Energy Technological Review - ENTRUST Project€¦ · Energy Technological Review Deliverable D2.2 Alberto Landini1, Tommaso Zerbi1, John Morrissey2, Stephen Axon2 ... Table 6: KPIs

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 657998

EnergyTechnological

ReviewDeliverable D2.2

AlbertoLandini1,TommasoZerbi1,JohnMorrissey2,StephenAxon2 1Stams.r.l.,Genoa,Italy2LiverpoolJohnMooresUniversity,Liverpool,UK

http://www.entrust-h2020.eu @EntrustH2020

Energy Technological Review

October 2016 Page 2 of 133

Document Information

History Date Submittedby Reviewedby Version(Notes)25Jan2016 AlbertoLandini(STAM) AllPartners A12Oct2016 AlbertoLandini(STAM) NiallDunphy(UCC) B(revisedandupdatedversion)

GrantAgreement#: 657998

ProjectTitle: EnergySystemTransitionThroughStakeholderActivation,EducationandSkillsDevelopment

ProjectAcronym: ENTRUST

ProjectStartDate: 01May2015

Relatedworkpackage: WP2:Mappingofenergysystem

Relatedtask(s): Task2.2Characterisationofthetechnologicalregime&emerginginnovations

LeadOrganisation: UniversityCollegeCork

Submissiondate: 15October2016(revisedandupdated)

DisseminationLevel: PU–Public



Table of Contents AbouttheENTRUSTProject.........................................................................................................6

ExecutiveSummary.....................................................................................................................7

1 Deliverablecontext..............................................................................................................81.1 OverviewofWorkPackage2.....................................................................................................81.2 ObjectivesofTask2.2................................................................................................................81.3 AimsofDeliverable2.2..............................................................................................................91.4 Deliverablestructure.................................................................................................................9

2 DefiningtheEnergySystem/Regime.................................................................................102.1 ProfilingtheEnergyRegimefortheENTRUSTProject...............................................................102.2 UnderstandingtheTechnologicalDimensionofEnergy:TheSupplyChainPerspective.............102.3 DefiningtheEnergySupplyChain.............................................................................................112.4 Overviewofcriticalenergysupplychainelements...................................................................122.5 RenewableEnergySupplyChains.............................................................................................14

3 MeasuringSupplyChainPerformance................................................................................153.1 SummaryofLiteratureFindingsonKeyPerformanceIndicators...............................................153.2 DefiningKPIsfortheEnergySupplyChain................................................................................183.3 SynthesisofReviewInsights:DefiningKPIsforENTRUSTTask2.2............................................193.4 KPIsevaluationprocess............................................................................................................24

4 Energyproduction..............................................................................................................254.1 Electricity.................................................................................................................................254.2 Districtheating.........................................................................................................................48

5 Energytransportationanddistribution...............................................................................555.1 Electricity.................................................................................................................................565.2 Oil............................................................................................................................................595.3 Gas...........................................................................................................................................625.4 Coal..........................................................................................................................................65

6 Energystorage....................................................................................................................686.1 Electricity.................................................................................................................................696.2 Oil............................................................................................................................................756.3 Gas...........................................................................................................................................766.4 Coal..........................................................................................................................................806.5 Heatstorage.............................................................................................................................81

7 Energyendusers................................................................................................................857.1 Lighting....................................................................................................................................877.2 MicroCHP................................................................................................................................927.3 Buildingheating.......................................................................................................................967.4 Ventilating.............................................................................................................................1027.5 Airconditioning......................................................................................................................1057.6 Buildingmonitoring,automationandcontrol.........................................................................1097.7 Transport...............................................................................................................................116

8 Conclusionandsynthesis..................................................................................................120

9 Bibliography.....................................................................................................................122



List of Tables

Table 1: Framework of Ideal KPIs to Characterise Energy Supply Chains ..................................... 20Table 2: Framework of Selected KPIs to Characterise Energy Supply Chains ............................... 21Table 3: KPIs for production, Transportation-Distribution and Storage phases .............................. 22Table 4: KPIs for End-user stage – HVAC systems ........................................................................ 23Table 5: KPIs for End-user stage – Lighting and Transport systems .............................................. 23Table 6: KPIs evaluation for non-renewable energies ..................................................................... 32Table 7: KPIs evaluation for renewable energies ............................................................................ 47Table 8: KPIs evaluation for district heating technologies ............................................................... 54Table 9: KPIs evaluation for electricity T&D .................................................................................... 58Table 10: KPIs evaluation for oil T&D ............................................................................................. 61Table 11: KPIs evaluation for natural gas T&D ............................................................................... 63Table 12: KPIs evaluation for coal T&D .......................................................................................... 67Table 13: KPIs evaluation for electricity storage ............................................................................. 74Table 14: KPIs evaluation for gas storage ...................................................................................... 79Table 15: KPIs evaluation for heat storage ..................................................................................... 84Table 16: KPIs evaluation for lighting technologies ......................................................................... 89Table 17: KPIs evaluation for lighting control systems .................................................................... 91Table 18: KPIs evaluation for micro CHP technologies ................................................................... 95Table 19: KPIs evaluation for building heating technologies ......................................................... 101Table 20: KPIs evaluation for ventilating solutions ........................................................................ 104Table 21: KPIs evaluation for air conditioning technologies .......................................................... 108Table 22: KPIs evaluation for building automation and control systems ....................................... 115Table 23: KPIs evaluation for private transport vehicles ............................................................... 118



List of Figures Figure 1: Generic Renewable Energy Supply Chain Process ........................................................ 15Figure 2: SMART criteria for KPI selection and application ............................................................ 16Figure 3: Production of primary energy, EU-28, 2013 .................................................................... 25Figure 4: Net electricity generation, EU-28, 2013 ........................................................................... 26Figure 5: Hydroelectric dam scheme .............................................................................................. 34Figure 6: Tidal barrage scheme ...................................................................................................... 36Figure 7: DTP scheme .................................................................................................................... 38Figure 8: Concentrator PV panel ..................................................................................................... 43Figure 9: Dry steam power station scheme ..................................................................................... 44Figure 10: CHP compared with separated power and heat generation ........................................ 50Figure 11 Coal stacking position .................................................................................................... 80Figure 12: Molten salt system ......................................................................................................... 82Figure 13: European final energy consumption by sector ............................................................... 85Figure 14: Stirling engine schematic view in Alpha, Beta and Gamma configurations ................... 94Figure 15: Condensing boiler scheme ............................................................................................. 98Figure 16: Heat pump cycle scheme ............................................................................................... 99Figure 17: Mechanical ventilation with heat recovery scheme ...................................................... 103Figure 18: Chiller process schematic view .................................................................................... 106Figure 19: HVAC control systems typologies ................................................................................ 111



AbouttheENTRUSTProjectENTRUST ismapping Europe’s energy system (key actors and their intersections, technologies,markets,policies,innovations)andaimstoachieveanin-depthunderstandingofhowhumanbehaviouraroundenergyisshapedbybothtechnologicalsystemsandsocio-demographicfactors(especiallygender,ageandsocio-economic status).Newunderstandingsofenergy-relatedpracticesandan intersectional approach to thesocio-demographicfactorsinenergyusewillbedeployedtoenhancestakeholderengagementinEurope’senergytransition.

Theroleofgenderwillbeilluminatedbyintersectionalanalysesofenergy-relatedbehaviourandattitudestowardsenergytechnologies,whichwillassesshowmultipleidentitiesandsocialpositionscombinetoshapepractices. These analyses will be integrated within a transitions management framework, which takesaccountofthecomplexmeshingofhumanvaluesandidentitieswithtechnologicalsystems.Thethirdkeyparadigminformingtheresearchistheconceptofenergycitizenship,withakeygoalofENTRUSTbeingtoenableindividualsovercomebarriersofgender,ageandsocio-economicstatustobecomeactiveparticipantsintheirownenergytransitions.

Centraltotheprojectwillbeanin-depthengagementwithfiveverydifferentcommunitiesacrossEuropethatwillbeinvitedtobeco-designersoftheirownenergytransition.Theconsortiumbringsadiversearrayofexpertisetobearinassistingandreflexivelymonitoringthesecommunitiesastheyworktotransformtheirenergy behaviours, generating innovative transition pathways and business models capable of beingreplicatedelsewhereinEurope.

Formoreinformation,seehttp://www.entrust-h2020.eu

ProjectPartners:

UniversityCollegeCork,Ireland

-CleanerProductionPromotionUnit(Coordinator)

-InstituteforSocialSciencein21stCentury

LiverpoolJohnMooresUniversity,UK

LGIConsulting,France

IntegratedEnvironmentalSolutionsLtd.,UK

Redinnsrl,Italy

EnerbyteSmartEnergySolutions,Spain

Stamsrl,Italy

CoordinatorContact:NiallDunphy,Director,CleanerProductionPromotionUnit,UniversityCollegeCork,Irelandt:+353214902521|e:[email protected]|w:www.ucc.ie/cppu



ExecutiveSummaryWP2aimstoundertakeanextensivecharacterisationoftheEuropeanenergysystem.Followingtheactorsandactor-networksanalysisrealisedduringTask2.1,theworkperformedduringTask2.2representsafurthersteptowardsthecompleteenergysystemcharacterisation,asitprovidesadetailedoverviewonthetechnologicalforcescurrentlydrivingit.

D2.2focusesonthetechnical/technologicalelementsoftheEnergySocio-Technicalregime,tocontributesignificantandrobustevidenceonwhatconstitutesaregime.Inordertodothis,asupplychainperspectivewasadopted.Therichliteratureonthetopicwasreviewedandsynthesised,andonthisbasisitwasdeemedmostappropriatetoapplyaKeyPerformanceIndicators(KPIs)approachinordertoassessandcharacterisetheenergysupplychain.AbestpracticemethodologyfordefiningandapplyingKPIswaspursued;forthisreason,anextensivereviewoftheacademicliteratureinthisareawasconductedandispresentedinthisdeliverable.Fromthisreview,ameansofidentifyingKPIstocharacterisetheEnergySupplyChainwasdeveloped,synthesisinginsightsfromstateoftheartknowledgeonthis.DevelopedKPIsrepresentacomprehensiveandinnovativemeansofcharacterisingtheEnergySupplyChainaccordingtoamyriadofmulti-dimensionalcriteria;typicallysupplychainsarecharacterisedonlyinnarroworsingledimensionalways.Throughthesesteps,evidenceonthetechnologicalelementsoftheEnergySupplyChainisproduced,enablingafullerunderstandingofthisaspectoftheenergyregime,andpresentingacriticalpartofthecase-bookthroughwhichtheEnergySocio-technicalregimewillbedefinedinENTRUST.

Inordertopresentthetechnologicalreviewinaclearandstructuredway,thecomplexandinterconnectedstructureoftheenergysupplychainwasdividedintoits4mainstages,(i.e.Production,Transportation&Distribution,Storage,andEndUser).Foreachstage,anintroductorydescriptionofthecurrentsituationatEuropeanlevelisprovided,inordertogivethereaderacontextualviewofthediscussedtopic.Then,themaintechnicalsolutioncurrentlyimplementedaredetailed,describingtheirfunctionalities,fieldsofimplementationandothercriticalaspectssuchas,forexample,environmentalimpact.

TheinformationprovidedduringthosesectionsisthencompletedthroughtheKPIstables,whichprovideaclearcomparisonbetweentheanalysedtechnologiesonamultiplelevel.ConsistencythroughallthedeliverableisguaranteedthankstothedefinitionofspecificthemesfortheKPIs,whichhavebeenusedasguidelinesforalltheevaluationtables.Inordertobetteraddresseachstageofthesupplychainandeachenergytypeparticularities,though,aspecificsetofKPIswasdefinedforeachconsideredgroupoftechnologies.

ThetechnologicalreviewprovidedinthisdeliverableD2.2,togetherwiththespecificKPIsevaluationproposedattheendofeachsection,givesaclearunderstandingofthecurrenttechnologicalforcesdrivingtheEuropeanenergysystemandassuchisfurthercontributiontothemulti-disciplinarycharacterisationapproachtakeninWP2oftheENTRUSTproject.



1 Deliverablecontext

1.1 OverviewofWorkPackage2AspertheDescriptionofAction:

WorkPackage2(WP2)seekstoinformandoutlinethescopeforsubsequentWPs.Itaimstoprovideaninitialmappingofsignificantfactorsthatneedtobetakenintoaccountwhenaimingtounderstandandfosteratransitionintheenergysystem.Itfocusesontwoperspectives inparticular–ontheactorsandtheirkeyinteractions;aswellasontechnological,economicandpoliticalsystems(energytechnologies,marketandpolicies).WP2proposestomapandillustratethecapacityofactorstochangetheenergysystem,aswellashowthesystemanditsoutputsconstrainactors’capacitytoact.Thetechnologicalreviewperformedthroughalltheenergysupplychainstageswillplayafundamentalroleinunderstandingwhicharetodayspossibilitiesandlimitationsoftheenergysystemanditspossiblefuturedevelopment.

1.2 ObjectivesofTask2.2AspertheDescriptionofAction:

T2.2“Characterisationof thetechnological regime&emerging innovations”aimsatmoving forwardtheenergysystemanalysisstartedwithT2.1,wherethemainactorsandactor-networkinfluencingtheEuropeanenergysystemhavebeeninvestigated.

InthisTaskthemainandemergingtechnologiesforeachstageofthesupplychainwillbeanalysed,providingdetailsontheirfunctioning,theiradvantagesanddisadvantagesandtheirroleinthecurrentenergysystem.Technologiesofthesamecategorywillbethencomparedthroughkeyperformanceindicators,inordertoprovideabetterviewofthepossiblefuturescenariosintheEuropeanenergysystem.

WP2aimstoundertakeanextensivecharacterisationofenergysystemactors.Abasicmapofenergysystemswillbeproducedconsistingofkeyactors,adescriptionoftheirkeyroles,andcriticalstrategicpointsofinteraction,consistentwithapracticebasedapproach.Actor-networktheorieswillbeappliedtodevelop insight intostakeholders’ interactions; communitiesof energyuseand the energysupplychainasacascading,interlinkedecosystem/networkoflinkedandinteractingstakeholders.Thisworkpackagewillinvolveacomparisonofenergysystemprofilefordiverseenergytechnologies,includingananalysis of how synergies can be found between them regarding evolution, market, policies anduptake/acceptance.

Task2.2aimstocharacteriseenergysystemtechnologicalregime,itsdrivingforcesandmainchallengesandopportunities.Thistaskwillidentifythemaintechnologiesusedalongtheenergysupplychain,fromgeneration,totransport,distributionuntiltheenduser.Newandemergingenergytechnologies,renewables,energyconservationmeasures(ECM)andretrofitsolutions,micro-generation,etc.willbeidentifiedthroughatechnologicalreview,augmentinginformationcapturedthroughthestakeholderanalysisfromtask2.1.Thesetechnologiesandprocesseswillbereviewedandkeyperformanceindicatorswillbedefinedtoascertaintheirpotentialvalue.



1.3 AimsofDeliverable2.2

Asdescribedinsection1.2,thisdeliverableisfocusedprimarilyontechnologicalaspects,butisdevelopedtosyncwith,andcomplement,outputscapturedthroughtheanalysisofstakeholdersproducedforTask2.1.Deliverable2.2reportsontheresearchactivitiesofTask2.2byconcentratingonthefollowingkeyareas:

• The primary technologies used along the energy supply chain across generation, transport,distributionandend-userstagesareidentified.

• Newandemergingenergyinnovationsaredescribed,includingnewtechnologies,renewableenergyinnovations,energyconservationmeasures(ECM)andretrofitopportunities.

• A review of best practice for the development of Key Performance Indicators is conducted tofacilitate state of the art regime characterisation, with goals of consistency, integration andrepresentativeness.

• AsetofKeyPerformanceindicatorsessentialforD2.2aredefinedonasystematic,targetedandstep-wisemanner;thesearedevelopedthematicallytoenablecomparisonacrossdisparatetechnologiesandspatialcontexts/countries.

• DiscreetKeyPerformanceIndicatorsaredevelopedandappliedforeachofthesupplychainstages.Particularattentionisgiventotheend-userstageduetotheuniquecharacterofthisstageanditscriticalimportantinbehaviourchangeinitiatives.

• Acomprehensiveandintegratedcharacterisationoftheenergysupplychainisproduced.

1.4 DeliverablestructureThedeliverableisbuiltasfollows:

• Supplychaindefinition:Thissectiongivesanoverviewonwhatisconsideredasenergysupplychainandwhattechnologicalcategorieshavebeenanalysedinthisdocument

• Key Performance Indicators definition: This part details the selection process for the keyperformance indicators that will be used throughout this deliverable to evaluate the reviewedtechnologies.

• Analysisoftheenergysupplychaintechnologies:Theenergysupplychainhasbeendividedintoits4mainstages(Production,TransportationandDistribution,Storage,Enduser)and,foreachoneofthose,themaintechnologieshavebeenconsideredandreviewed.

• Synthesisandconclusion



2 DefiningtheEnergySystem/Regime

2.1 ProfilingtheEnergyRegimefortheENTRUSTProject

Sustainabilitytransitionsarecharacterisedbysubstantiallyenhancedecologicalefficiencywithinnewsocio-technologicalconfigurations(Coenenetal.,2012).Withinasustainabilitytransitioncontext,anenergytransitioncanbedefinedasaswitchfromaneconomicsystemdependentononeoraseriesofenergysourcesandtechnologiestoanalternativeparadigm(Crabbéetal.,2013).Fromanenergyperspective,itisincreasinglyapparentthatcurrentenergysystemsareunsustainableacrossamyriadofsocial,economic,andenvironmentalcriteria(Grübler,2012),somuchsothatanenergytransitiontoalow-carbonmodelisnecessarytomeetthechallengeofclimatechangeandtobringhumanactivitiesbackwithinecologicalboundaries(Meadowcroft,2009;SolomonandKrishna,2011).

Withthetransitionsliterature,systemsintransitionarecommonlyrepresentedassocio-technicalregimes;definedasrelativelystableconfigurationsofinstitutions,techniquesandartefacts,aswellasrules,practicesandnetworksthatdeterminethe‘normal’developmentanduseoftechnologies(RipandKemp,1998;A.Smithetal.,2005).Afocusonregimesrecognisesthatorganisationsandtechnologiesareembeddedwithinwidersocialandeconomicsystems(Rip&Kemp,1998).Socio-technicalsystemsarethusconceptualisedasclustersofalignedelements,suchastechnicalartefacts,knowledge,markets,regulation,culturalmeaning,rules,infrastructure(Kern,2012).

ForthepurposesoftheENTRUSTproject,itisnecessarytodevelopacomprehensiveprofileofwhatwedeemtobetheenergysystemsocio-technicalregime.Thiswillbecompletedinanintegratedandmulti-dimensionalmanneracrossarangeofWorkPackagesandDeliverables;afullprofileofbothsocialandtechnicalelementswillemergeacrossthiswork,ultimatelycontributingtoacomprehensivewhole.Namely,WP2(T2.1&T2.2),WP3(T3.1-3.4),WP4(T4.1&T4.3)andWP5(T5.3)willallproviderobustevidencewhichcumulativelywillbeappliedtoinformtheENTRUSTproject’sprofileoftheEnergySystemsocio-technicalregime.

2.2 Understanding the Technological Dimension of Energy: The Supply ChainPerspective

Single,orstandalone,businessentitiesarealmostnon-existenttoday;morecommonly,organisationsbelongtoanetworkofentitiesatdifferentstagesinasupplychain1.Theoutputofonestageistheinputtoanother;consequently,theenvironmentaldecisionsmadeatonestageofasupplychainareaffectedbythosemadeatpriorstagesandwillaffectthosemadeinsubsequentstages(ElSaadany,Jaber,&Bonney,2011).Althoughnewtechnology,products,marketsandretailformatsremaincriticaltocompetitiveadvantage,supplychainperformanceimprovementsveryoftenpromisethegreatestpositiveimpactoneconomicprofitandshareholdervalue,duetoatraditionalunder-realisationofsupplychainpotentials(Stank,Dittmann,&Autry,2011).Sustainablesupplychains(SSC)areakeycomponentofsustainabledevelopmentinwhichkeyenvironmentalandsocialperformancemeasuresactaskeycriteriaforsupplychainmembership,whilecompetitivenessismaintainedthroughthedeliveryofvaluetoendusers(Taticchi,Tonelli,&Pasqualino,2013).However,extendingthesupplychaintoincludesustainabilityconcerns,includingissuessuchasremanufacturingandrecycling,addscomplexitytosupplychaindesignaswellaspotentialstrategicandoperationalissues(Sivadasan,Efstathiou,Calinescu,&HuacchoHuatuco,

1 Asupplychainisacomplexnetworkinvolvingmanystakeholders(ElSaadanyetal.,2011).



2004;Taticchietal.,2013).Theissueofcompetinggoalsandobjectiveswouldappeartobeacentralchallengetosustainabilitydebates,andthisiscertainlyevidentinthecaseofsustainablesupplychains(Shepherd&Günter,2006).Supplychainmanagersinteractwithmultipledecisionmakers.Inaddition,thereconciliationofthemitigationofenvironmentalimpactsanddeliveryofsocialbenefits,togetherwithvalueacrossstakeholdersinamulti-partysupplychainisaverycomplextask(Taticchietal.,2013).Practicessuchasjust-in-timeimplicitlyprivilegecertainmetrics,whichmayormaynotbealignedwiththecurrentstrategicobjectives(Shepherd&Günter,2006).Forexample,whilstjust-in-timeencourageslowinventorylevels,thismayconflictwiththestrategicgoalofincreasedsupplychainflexibility(Ibid.)orindeedwithde-materialisationandenergyreductionimperativesofsustainability.Inaddition,existingmeasurementsystemsforevaluatingtheperformanceofsupplychainstendtobestaticratherthandynamic(Shepherd&Günter,2006).

Coordinatingthelevels(suppliers,manufacturers,distributors,etc.)ofasupplychainisnecessarytodeliverproductsand/orservicestocustomersthatconformtotheirrequirements(includingenvironmentalones)(ElSaadanyetal.,2011).Asupplychaincanbedescribedasoptimisedwhentheoperationsofthemanufacturerandretailersarecoordinated(ElSaadanyetal.,2011).However,thereremainaplethoraofbarrierstosupplychainoptimisation,particularlywithregardtosustainabilitycriteria.Manyfirmsretainatraditional“functional”viewofthesupplychain,seeingitonlyasthearearesponsibleforthelogisticsofmaterialflow,andarethusunabletomakethestrategiclinkbetweensupplychainperformanceandshareholdervalue(Stanketal.,2011).Environmentalconcernshavebeenexaminedandtreatedseparatelyinsupplychainfunctionsandthereisasyetnointegrativeapproachnormechanismthatmeasures,controls,andimprovestheenvironmentalaspectsofanentiresupplychain(ElSaadanyetal.,2011).Infact,thereisadearthofresearchontheenvironmentalperformanceofthesupplychainasawhole.Nostudiesexistwhichquantifythequalityoftheenvironmentalperformanceofasupplychain(ElSaadanyetal.,2011).Optimisinginventoryinasupplychain,whiletakingenvironmentalfactorsintoconsideration,isavitalresearcharea;asmuchforenergysupplychainsasforsupplychainsofthemanufacturingsector(ElSaadanyetal.,2011).

2.3 DefiningtheEnergySupplyChain

Thetraditionalsupplychainisdefinedasanintegratedmanufacturingprocesswhereinrawmaterialsaremanufacturedintofinalproducts,thendeliveredtocustomers(viadistribution,retailorboth)(Beamon,1999b).Essentially,supplychainsrepresentthemovementofmaterialsastheyflowfromtheirsourcetotheconsumer.Thereare4mainelementsthatconstitutetheenergysupplychain.Theseare:(1)thegenerationofenergy;(2)transmissionofenergyoverlongdistances;(3)thedistributionofenergytoconsumers;and(4)theconsumptionofenergy.

Forsimplicity,asliteratureismuchmoreconsistentontheelectricitysupplychain,wearegoingtorefertotheelectricalcaseinordertoprovideaclearerexampletothereader.Thiscanbedonesince,withtheexceptionofthespecifictechnologiesconsidered,thestructureandstagesofthesupplychainarecomparableforalltypesofenergy.

Electricitycanbegeneratedfromfossilfuelssuchascoal,oilandgas,orrenewablesourcessuchashydroandwindpower.Followinggeneration,bulkelectricityistransportedviaextrahighvoltageelectricitytransmissionlines.Thevoltageofbulk-transmittedenergyisreducedviasubstationtransformersthatconverthighvoltageelectricitytolowvoltagefordistribution.Inmanyexamples,thereareoftenanumberofdistributionsubstationsthatreducedthevoltageofelectricityfordistributiontoconsumers.Followingthis,electricityisthencirculatedthroughdistributionlinesthatcarryenergytogroundleveltransformerstationsorlowvoltagestreetmainsthattravelalongundergroundwiresdirectlytohomesandbusinesses.Thisenergydirectlypassesthroughanenergymeter,whichrecordstheamountofenergyusedinhomes



andbusinessestoprovideanaccurateassessmentoftheamountofenergyconsumed,whichtheenergyprovidercanthenchargefor.

Inenergysupplyplanningandsupplychaindesign,thecouplingbetweenlong-termplanningdecisionslikecapitalinvestmentandshort-termoperationdecisionslikedispatchingpresentachallenge,waitingtobetackledbysystemsandcontrolengineers.Thecouplingisfurthercomplicatedbyuncertainties,whichmayarisefromseveralsourcesincludingthemarket,politics,andtechnology(Lee,2014).Supplychainsarecharacterisedbytheinteractionofmultiple-actors,whichisthecaseforenergysupplychainsasforanyother,andthelevelofco-operationacrossorganisationalboundariescanbeakeydeterminantofsuccess.Forinstance,Wagner&Schaltegger(2004)reportthatfirmswithshareholdervalue-orientedstrategieshaveamorepositiverelationshipbetweenenvironmentalperformanceanddifferentdimensionsofeconomicperformancethanfirmswithoutsuchstrategies.Manufacturersarelookingtosupplierstoworkco-operativelyinprovidingimprovedservice,technologicalinnovationandproductdesign,forinstance(Gunasekaran,Patel,&Mcgaughey,2004).Energysupplychainoptimisationnthereforepresentsamajorchallengeduetothemulti-scalenatureandsignificantuncertainties(Lee,2014).

2.4 Overviewofcriticalenergysupplychainelements

2.4.1 Introduction:Energyproduction

2.4.1.1 Electricity

Electricityisproducedbyrenewable(e.g.solar,bioenergy,wind)andnon-renewable(e.g.coal,oil,naturalgas)sourcesofenergy.AccountingfortheseelementsoftheenergysupplychainforthisDeliverable,thereareamultitudeofdifferenttechnologiesthatareusedincludingwindturbines;photovoltaicpanels;steamengines;fuelcells;dieselengines;solarpanels;groundsourceheatpumps;andelementsthatmakeuppowerplantsincludingalternators,turbinesandelectricalgenerators.

2.4.1.2 District heating

Traditionally,homeshavebeenheatedwithwood,themosteasilyobtainablesourceofheat,andmorerecentlywithnaturalgasandoil.TodayinEurope,thepredominantwayinwhichtoheathomesisthroughgasboilersratherthanelectricstorageheaterandoilburners,asthisisacheapersourceofheatingfordomesticbuildings.Thissectionconcentratesondifferenttechnologiesusedincentralisedsolutionsfordistrictheating.Whenitispossibletoimplement,districtheatingprovidessomeadvantagesoversinglebuildingsolutions,sinceithelpssaveenergyandthusreducingpollutantemissionsintheair.Thepresenceofasinglebiggercentralunitprovidesasimplerandmoreefficientcontrol,avoidingwastesinfuelconsumption.

Asaparticularwaytogenerateheatthroughrecoveryofelectricalpowerplantsexhaustgases,cogenerationisconsideredinthischapteraswell.Cogeneration,orcombinedheatandpower,istheuseofaheatengineorpowerstationtogenerateelectricityandusefulheatatthesametime.Itisathermodynamicallyefficientuseoffuel,asintheseparateproductionofelectricitysomeenergyisdiscardedaswasteheat.Commoncombinedheatandpowerplanttypesaregasturbines,biofuelengines,biomass,steamturbineandnuclearpowerplants.

2.4.2 Introduction:Energytransportationanddistribution

Energytransportationanddistributionusuallyoccursthroughaseriesoftechnologies.Afterelectricityisgeneratedatapowerstation,itistransportedthroughoverheadandundergroundcablestostepuptransformers,whichcarryelectricityacrosslargedistances,beforeenteringresidentialbuildingsthrough



step-downtransformers,transmissionsub-stations,andlocaldistributionsub-stations.Thesenetworksusecomponentssuchaspowerlines,cables,transmissionlines,substations,circuitbreakers,capacitorbanks,transformersandswitches.

2.4.3 Introduction:Energystorage

Oneofthedistinctivecharacteristicsofthepowersectoristhattheamountofelectricitythatcanbegeneratedisrelativelyfixedovershorttimeperiods,althoughdemandfluctuatesthroughouttheday.Electricitystoragedevicescanmanagetheamountofpowerrequiredtosupplycustomersattimeswhenneedisgreatestduringpeakload.Suchdevicescanalsohelprenewableenergy,whosepowercannotbecontrolledbygridoperators.Energystoragedevicescanprovidefrequencyregulationtomaintainthebalancebetweenthenetwork’sloadandpowergenerated;achievingamorereliablepowersupplyforhightechindustrialfacilities.Energystoragesystemsprovideanarrayoftechnologicalapproachesformanagingpowersupplytocreateamoreresilientenergyinfrastructure,bringingcostsavingstoend-users.

2.4.4 Introduction:EndusertechnologiesThisDeliverablefocusesonend-usertechnologies,especially‘privatecitizentechnologies’thatareshapedbytheenergy-specificbehavioursandpracticesofthesesameindividuals.Lighting,transport,heating,ventilation,airconditioningandcontrolsystemswereallconsidered,andarediscussedbelow.

2.4.4.1 Lighting

Lightingtechnologiesareheavilyinfluencedbysocialpracticesandbehaviours.TherelevanceofKeyPerformanceIndicators(KPIs)onlightingtechnologiesandcontrolsystemsisexplored,particularlythoserelatedtoefficiencyandenergyconsumption,includinghalogenandLEDlightbulbs.Otheraspectsoflightingcontrolsmayincludeoccupancysensors,time-locks,andphotocellshard-wiredtocontrolfixedgroupsoflightsindependently.Lightingcontrolsystems,however,referstoanintelligentnetworkedsystemofdevicesrelatedtolightingcontrol,includingdimmers,timers,photocells,occupancysensors.Increasingdemandforenergyefficiencyfromend-usersreflectsdesirestoreduceenergyconsumptionandcosts.

2.4.4.2 HVAC

Heating,Ventilation,AirConditioning(HVAC)andtheircontrolsystemsrelatetothetechnologiesofindoorandvehicularenvironmentalcomfort,notablytoensurethermalcomfortandacceptableindoorairquality.HVACsystemsareimportantinthedesignofbuildings,particularlylargedomesticbuildings,skyscrapersandoffices,ensuringsafebuildingconditionswithrespecttotemperatureandhumidity.HVACsystemsusemultipletechnologies,includingsolidfuel,liquidandgasheaters,heatpumps,dehumidifiers,fans,stand-aloneairconditioningunits,solarpanelsandmanyothers.

2.4.4.3 Transport

InmostWesternEuropeancountries,suchastheUK,overathirdofenergyconsumedbyindividualsisusedfortransportation.Thisisoftencharacterisedbyprivatetransportusesuchascarsratherthanpublictransportsuchasbuses,railandplane.Privatetransport,andsomepublictransport(e.g.,buses),canoperatewithdiesel,gasoline,hybridorelectricsourcesofenergy,yetsignificantcostbarriersexistwiththeadoptionofhybridandelectricvehicles.Whilstgasolineanddieselcarsarepredominant,thenumberofhybridandelectricprivatevehicleshasincreasedfour-foldacrosstheEuropeanUnion.Latestdevelopmentsinprivateandpublictransportuseincludeadvancedrangecapabilitiesforhybridandelectricvehicleswithouttheneedforaplug-incapability.



2.5 RenewableEnergySupplyChainsRenewableEnergy(RE)isaresourcethatisnaturallyregeneratedoverashorttimescaleandderiveddirectlyfromthesun(suchasthermal,photochemical,andphotoelectric),indirectlyfromthesun(suchaswind,hydropower,andphotosyntheticenergystoredinbiomass),orfromothernaturalmovementsandmechanismsoftheenvironment(suchasgeothermalandtidalenergy)(Cucchiella&Adamo,2013).Likemanytypicalsupplychains,theelementsofREsupplychainincludethephysical,information,andfinancialflows.Fromthephysicalflowperspective,industry’sincreasingawarenessofgreenmanufacturingprocesses,logistics,andproductshasbecomerelevanttoitssupplychainmanagementperformance(Wee,Yang,Chou,&Padilan,2012).TotalglobalinvestmentinREreachedUSD257billionin2011,upfromUSD220billionin2010.(Cucchiella&Adamo,2013).Recentestimatesindicatethatabout5millionpeopleworldwideworkeitherdirectlyorindirectlyintheREindustries:22%ofthesebasedintheEuropeanUnion(Cucchiella&Adamo,2013).CucchiellaandAdamonotethatthepotentialofrenewableenergyissignificantbutactiononmanyfrontsisrequiredforthispotentialtoberealised,including:

• FosteringthecompetitivemarketandresearchintheREsector

• Promotionofnetworksofdistribution,advancedstoragetechnologyandenergyefficiency

• Developmentofproductionprocesseswithalowcarbonfootprint

• Reuse,recyclingandenergyrecoveryfromgoods

• Participationofcitizensinenergysystemdesignandmanagement.

Thedesignandshapingofsupplychainsisofconsiderableimportanceinrenewableenergysectors.Theeffectivenessofsuchdesigneffortsmaydeterminetheestablishmentandgrowthofasustainableenergysubsystem(Genus&Mafakheri,2014).Forexample,designdecisionsdeterminetheoverallstructureofthebio-fuelproductionnetworkthroughcapacityinvestment,productiontechnologyandlocationchoices.Theycanbeconsideredasone-timedecisions,ormulti-stagedecisionstobemadeatvarioustimepointsoveraplanninghorizon.Ontopofthese,thereareshort-termdecisionsontheprocurementofbiomass,processing,anddistributionofproducts(Lee,2014).Thesupportstructurethatfeedsintothesuccessofallareasofrenewablepowermanufacturingisthereforethebackbonethatcreatessuccessorfailureformanufacturers.TosucceedintheREmarket,anymanufacturermustlookatwhotheychoosetopartnerwithforsupportandanswerthequestion:“Whatbenefitsdoesthiscompany,product,materialorserviceprovide?”(Laird,2012).Liketraditionalsourcesofelectricpowergeneration,eachREtypeislimitedbytheinherentcharacteristicsoftheenergysource.Intermittency,variability,andmanoeuvrabilityarethreekeyvariablesofREresourcesthatrequireeffectivemanagementandcontrol.Inaddition,duetothenatureofRE,asecondconversionprocesstosaveenergyforuseinoff-hoursisnecessary(Weeetal.,2012).TheREsupplychainlinksthesourceofenergywithotherapplications.TheperformanceoftheREsupplychainrelatestoitsconversionefficiencywhichincludesstorage,distribution,efficiencyandsecondaryapplicationefficiencies(Weeetal.,2012).Theincreasingroleofrenewablesourcessuchaswindandsolarnecessitatestheuseofafine-grainedtimescaleforaccurateassessmentoftheirvalues.Useofstorageintendedtoovercomethelimitationsofintermittentsourcesputsfurtherdemandsonmodellingandoptimisationnchallenges,includingnumericalchallengesthatarisefromthemulti-scalenatureanduncertainties(Lee,2014).



Figure1:GenericRenewableEnergySupplyChainProcess(Weeetal.,2012)

3 MeasuringSupplyChainPerformance

3.1 SummaryofLiteratureFindingsonKeyPerformanceIndicatorsSupplymanagementinvolvesmanagingupstreamsupplychain,includingprocurementorpurchasing;involvingmake-or-buydecisions,outsourcingdecisions,virtualenterpriseoperations,selectingsuppliers,in-sourcing,andoff-shoring(AngappaGunasekaran&Spalanzani,2012).Attheorganisationnallevel,competingincomplexandcontinuouslychangingenvironmentsrequiresadynamicapproachtomeasure,monitor,andmanageorganisationnalperformanceinitsmultipledimensions(Taticchietal.,2013).

Aperformancemeasure,orsetofperformancemeasures,isusedtodeterminetheefficiencyand/oreffectivenessofanexistingsystem,aswellascomparingalternativesystems(Beamon,1999b),includingmanagementalternativesacrossthesystem.Performancemeasuresandmetricsopenupthepossibilitiesoflookingatthebestalternativesanddecisions(AngappaGunasekaran&Spalanzani,2012).Animportantcomponentinsupplychaindesignandanalysisistheestablishmentofappropriateperformancemeasures.However,choosinganappropriatesupplychainperformancemeasureisdifficultduetothecomplexityofthesesystems(Beamon,1999a).Traditionalsupplychainsystemsidentifyanumberofmeasuresthataretypicallyconcernedwithcustomersatisfactionorcost.However,movingtowardsmorenuancedandmeaningfulperformancemeasuresarevitalforsupportingsustainableenergytransitions(Lehtonen,2013).Aneffectivesetofperformancemeasuresandmetrics(PMM)arecriticalforsuccessfulimplementationofsustainabilityprogrammesandactionsoverboththeshortandlongterm(AngappaGunasekaran&Spalanzani,2012).SuchKeyPerformanceIndicators(KPIs)havedifferenttypesofapplicationandinfluence;intheenergysupplychain,KPIscanbeappliedinternally(forownworkingsandcalculations);externally(e.g.,communicationwithpolicyinstitutionsandstakeholders);andsupportfurtherdecision-making(e.g.,useinofficialreportsandevaluatingprogress)(Lehtonen,2013).Goodperformanceindicatorsaredirect,objective,quantitative,disaggregatedaswellasbeingpracticalanduseable



(Carlucci,2010).ShahinandMahbod(2007)putforwardSMARTcriteriaforKPIselectionandapplication,thatisSpecific,Measurable,Attainable,RealisticandTime-sensitiveindicators(Figure2).

Figure2:SMARTcriteriaforKPIselectionandapplication,after(Shahin&Mahbod,2007)

PerformancemetricsorKPIsprovideuswithanoverallvisibilityofthesupplychainandhelpinassessingtheaccuracyofsupply/demandplan(e.g.,forecastaccuracy),andtheexecutionperformance(e.g.,actualsalesversusforecastplan).KPIsrevealthegapbetweenplanandexecutionandofferopportunitiestoidentifyandcorrectpotentialproblems(Chae,2009),ortohelpsteersupplychainperformanceinnewdirections(lowenvironmentalimpact)2.Performancemeasurementormonitoringoffervitalfeedbackinformationontheperformanceofthesupplychain(Chae,2009).Ameasurementsystemshouldfacilitatetheassignmentofmetricstowheretheywouldbemostappropriate.Foreffectiveperformancemeasurementandimprovement,measurementgoalsmustrepresentorganisationalgoals,andthemetricsselectedshouldreflectabalancebetweenfinancialandnon-financialmeasuresthatcanberelatedtostrategic,tacticalandoperationallevelsofdecisionmakingandcontrol(Gunasekaranetal.,2004).

Therehasbeenincreasingattentiongiventonon-financialperformancemeasuresalongsidefinancialmeasures(ElSaadanyetal.,2011),anaspectwhichtodate,hasseenadearthofresearch.LittleattentionhasbeengiventomeasuringperformanceinthecontextofSustainableSupplychainsforinstance(Taticchietal.,2013)3.Fewstudiesprovideaperformancemeasurement(PM)inter-organisationalperspectiveinvolvingthekeysupplychainstakeholders,forinstance(Taticchietal.,2013).Therehavebeenrelativelyfewattemptstosystematicallycollatemeasuresforevaluatingtheperformanceofsupplychains.Moreover,thereisalackofconsensusoverthemostappropriatewaytocategorisethem(Shepherd&Günter,2006).Consistentcriticismshighlightthelimitsofavailableperformancemeasurementforsupplychains(Shepherd&Günter,2006;Taticchietal.,2013).Theseinclude:

• Lackofconnectionwithstrategy;

2Theintegrationofsustainabilityconsiderationsurgentlyrequirestheadaptationofbusinessprocessesandnewwaysofthinkingaboutcorporateperformancemeasurement,accordingtoSearcyetal.(2005)3Performance measurements and metrics in SCM have not received due attention from both researchers andpractitioners(Gunasekaran&Chung,2004).



• Focusoncosttothedetrimentofnon-costindicators;

• Lackofabalancedapproach(e.g.,insufficientfocusoncustomersandcompetitors);

• Lackofsystemthinking(thatencourageslocaloptimisation).

Typicalmeasurementsystemsformanufacturingsupplychains,forexample,encourageshorttermism;theylackstrategicfocusandfailtoprovideadequateinformationonwhatcompetitorsaredoingthroughbenchmarking(Shepherd&Günter,2006).However,performancemeasurementsandmetricshaveanimportantroletoplayinevaluatingperformanceandsettingfuturecourseofactionsandobjectives(A.Gunasekaran&Chung,2004),particularlywhenaddressingpressingsustainabilityimperatives.TheSCORmodelproposedbytheSupply-ChainCouncil(2013)suggeststomeasureperformancebasedonfivekeysupplychainprocesses;plan,source,make,deliverandreturn(APICSSupplyChainCouncil,2015;Taticchietal.,2013).

From a business and economic perspective, Cabeza et al. (2015) suggest that a KPI is a performancemeasurementthatevaluatesthesuccessofaparticularactivity.Successcanbeeithertheachievementofanoperationalgoal(e.g.,zerodefects,customsatisfaction,etc.)ortheprogresstowardstrategicgoals.Selectingthe right KPI relies upon a good understanding of what is important to the application/technology/etc.AspectssuchasthepresentstateofatechnologyanditskeyactivitiesneedtobeassessedandarecoretotheselectionoftheKPIs (Cabezaetal.,2015).Cabezaetal. (2015)notethatKPIsareextensivelyused inbusiness and financial assessments, and are gaining more importance in technical assessments. KeycharacteristicsofKPIsinclude:

- Quantitative or qualitative indicators: The KPI may be measurable by giving a magnitude value(quantitative)orbygivingaqualitativedescriptionwithoutscale.

- Leading and lagging indicators: The KPI predicts the outcome of a process (leading KPI) or presentssuccessorfailureposthoc(laggingKPI).

- Processstageindicators:TheKPImeasurestheamountofresourcesconsumedduringthegenerationofanoutcome,representstheefficiencyoftheproductionoftheprocess,orreflectstheoutcomeorresultsoftheprocessactivities.

- Directionalindicators:TheKPIspecifieswhetherornotonetechnology/applicationisbeingpromotedand getting better – typically in the context of important performance parameters, e.g., carbonreduction.

- Financialindicators:TheKPItakesintoaccounttheeconomicaspectsofonetechnology/application.

UtilisingKPIsinameaningfulwayacrossthesupplychainisessentialtorecord,measureandmanageareasthatneedtobeimproved.Forexample,utilisingnumericalperformancesystemsorusingreadilyavailabledataappliedoveralongtime-period(orasatime-series)canprovideamoremeaningfulassessmentofenergysupplychainsthansimplisticqualitativeevaluationssuchas“good”,“adequate”and“poor”(Beamon,1999a).Yetsuchmeasurescanoftenbeimpracticalforusebycertainstakeholdersifthesedonotprovideclear,conciseandrelevantmessagesthatareaccessibletoawiderangeofenergyunderstandingsandliteracy.



AtypicalfirmalreadyhasacertainnumberofKPIs,suchasreturnoninvestmentforassessingitsfinancialperformance,butsupplychainrelatedKPIshavenotbeenwidelyadoptedandbusinessesaretypicallyuninformedofthem(Chae,2009).However,thereremainsalackofpracticalguidelinesonhowtodevelopKPIs,andanunderstandingofhowtodefineKPIsfortheirsupply/demandchainremainslackingattheoperationallevel(Chae,2009).

3.2 DefiningKPIsfortheEnergySupplyChain

3.2.1 KeyPerformanceIndicatorDesignandDevelopmentProcessAnindicatordesignprocessprovidesastep-by-stepguideforthedevelopmentofindicators(Searcy,Karapetrovic,&Mccartney,2005).Further,Searcyetal.(2005)forwardthefollowingprocessforindicatordevelopment:

• Developingaconceptualframework• Identifyingthekeyissuesthatmustbeaddressed• Developingindicatorselectioncriteria• Developingadraftsystemofindicators

Intermsofenergysupplychains,Gunasekaranetal.(2004)indicateanumberofareasthatcouldbeusedasaframeworkforsustainableenergysupplychainperformancemeasurement.Theseinclude:(1)anevaluationofthesupplylinks;(2)anevaluationofthedeliverylinks;(3)measuresfordeliveryperformance;(4)theflexibilityofthesupplychaintoprovideenergythatmeetstheindividualdemandsoftheconsumer;and(5)cost-basedanalysisthatrelatestoelementssurroundingreturnsoninvestmentandinformationprocessingcosts.Measuringthegreennessofasystemingeneral,oraspecificsupplychain,shouldbeflexibletoallowchangingprioritieswithchangingindustriesorproducts(ElSaadanyetal.,2011).Withrespecttothermalenergystorage(TES)KPIs,Cabezaetal.(2015)identifyasubstantialpolicyandpracticegap.Upuntilnow,onlyKPIsforTESinsolarpowerplantsandinbuildingscanbefound.WhileCabezaetal.(2015)quantifyandcomparetheseexistingKPIs,theyalsoindicatethatTEScanonlybeimplementedbypolicymakersifmoreKPIsareidentifiedformoreapplications.

Productionsustainabilityincludesmanagingtheprocesseswithsustainableinputssuchasenergy,people,equipmentandmachineswiththeobjectiveofreducingwaste,rework,inventoryanddelaysaswellasreducingcarbonemissions(AngappaGunasekaran&Spalanzani,2012).Measuringtheenergyefficiencyperformanceofequipment,processesandfactoriesisthefirststeptoeffectiveenergymanagementinproduction(Mayetal.,2015).Mayetal.(2015),addressthechallengewherebycurrentindustrialapproacheslackthemeansandtheappropriateperformanceindicatorstocompareenergy-useprofilesofmachinesandprocesses,andforthecomparisonoftheirenergyefficiencyperformancetothatofcompetitors’.Mayetal.(2015)thereforepresenta7-stepmethodwhichsupportsmanufacturingcompaniesinthedevelopmentofproduction-tailoredandenergy-basedperformanceindicators.This7-stepmethodinvolves:(1)adefinitionofthereferenceproductionsystem;(2)identificationofdifferentpowerrequirementsoftheproductiveresource;(3)analysisofmanufacturingstatesascausesofenergyinefficienciesoftheproductiveresource;(4)linkingmanufacturingstateswithenergystates;(5)buildingahierarchicalframeworkofmachine’senergyconsumption;(6)developmentofenvironmental-KPIs(e-KPIs);and(7)e-KPIdesignandmanagement.Examplesofsuche-KPIsmayincludeleanenergyindicators



calculatingthenetenergyconsumptionoveroverallenergyconsumptionandoverallenergyusagewherebynetusageenergyisdividedbyenergyinoperatingtime(Mayetal.,2015).

Manufacturingperformanceisusuallyassessedintermsofcost,quality,delivery,andflexibility,whereasenvironmentalperformancecommonlymeasurestheamountsofpollutantsreleasedintotheairfromindustrialplants,andhazardoussubstancestransferredfromandtootherplants/marketsthatprobablyend-upaslandfillaffectingsoilandwaterquality(ElSaadanyetal.,2011).TheproposedmethodbyMayetal.(2015)supportstheidentificationofweaknessesandareasforenergyefficiencyimprovementsrelatedtothemanagementofproductionandoperations.Additionally,thismethodalsostrengthensthetheoreticalbasenecessarytosupportenergy-baseddecision-makinginmanufacturingindustries.Step7isanimportantpartofthisapproach.OncetheKPIsystemisdesigned,itmustbemanagedforthepurposeforwhichithasbeencreatedinordertoenablethecontinuousimprovementofenergy-relatedindicators(Mayetal.,2015).Neglectingtodosowouldleadtoalackofmonitoringandmeasurementresultinginalackofprogresstowardssustainabilityintheenergysupplychain.

Finally,thefullsetofdevelopedKPIsneedstobelimitedandrestrictedinnumbertoalloweaseofuseandinterpretation,aswellastoenableregularupdatesandapplication/managementresponses.Forinstance,DEFRAreportthat80%ofbusinessesoftenhave5orfewerKPIsmonitoringenvironmentalperformance,DEFRA(2006)promoteavoluntarysetofguidelinesfor22KPIs(reportedinfullinDEFRA,2006).

3.3 SynthesisofReviewInsights:DefiningKPIsforENTRUSTTask2.2ThefollowingprocesswasappliedtoselectKPIsforthecharacterisationofenergysupplychains:

1. KeyThemesforKPIswereidentified,accordingtosustainability(triplebottomline)principles

2. ThemesweredividedintoStrategic,TacticalandOperationaldimensionsfollowinginsightsfromtheliterature,andallowingdifferentiationofindicatorsatarangeofscales

3. Foreachtheme,asetofIdealIndicatorswasdefinedforeachdimension

4. Thesewerereviewedbymultipleprojectpartnersandassessedforsuitability,levelofappropriatenessandpracticalityinimplementation

5. Followingtheinternalpeerreviewprocessandsubsequentbrainstormingconferencecalls,someadditionalindicatorswereincludedinthelistofIdealIndicators(Table3)

6. Criticalreviewidentifiedthoseindicatorsmostsuitabletothefullindicatordevelopmentstageaswellasthoseindicatorswhichweredeemedunsuitablefordevelopmentatthispointofanalysis.Atthispointofanalysis,certainindicatorswereexcludedforarangeofreasons,includingpracticalitiessuchasdataavailability,abilitytoconciselycommunicateindicatorsandreplicabilityacrossenergysupplychainstagesandtechnologies.

7. AfinalgeneralselectionofKPIswasderivedfollowingthisprocessandtheseweredevelopedtoprovideacomprehensivecharacterisationofenergysupplychains(Table4).MainaimofthisphaseisthedefinitionoftheKPIthemes,whichwillbeusedasacommonguidelinethroughallthedocument.

8. Separatetothisindicatordevelopmentprocess,adiscreetsetofindicatorswasdevelopedforeachspecificstageoftheenergysupplychain.Thisdeeperlevelofindicatorsdefinitionisduetotheassessmentoftheresearchteamthattheuniquecharacterofeachstageandofeachcategory



definedinthatstagecannotbeaddressedinageneralandintegrative/comprehensiveway.Thisisparticularlytrueforend-userstage,sinceitscriticalimportanceinbehaviourchangeinitiativeswarrantedspecificandtailoredcharacterisationthroughbespokeend-userkeyperformanceindicators.

9. KeyPerformanceIndicatorsfortheProduction,Transportation-DistributionandStoragestagesarepresentedinError!Referencesourcenotfound..KPIsforEnd-userstageoftheenergysupplychainarepresentedinTable4and

10. Table5.

Table1presentstheinitialFrameworkofIdealKeyPerformanceIndicatorstoCharacteriseEnergySupplyChains.Therationaleofthistableistomaintainthedefinedthemesasaguidingframeworkacrossallrelevanttechnologiesaddressed;toprovideconsistencyandastandardisedapproachtothecharacterisationoftheenergysupplychainasawholeandtoensurethatarangeofperspectives/scaleswasprovidedforeachthemeinvestigated.

Table1:FrameworkofIdealKeyPerformanceIndicatorstoCharacteriseEnergySupplyChains

Theme StrategicLevelIndicators TacticalLevelIndicatorsOperationalLevelIndicators

GreenhousegasContributiontonationalGHGprofile

Locationofemissionsarisinginsupplychain

GHGprofile@operationallevel

WasteGenerationContributiontonationalwasteprofile HazardousWaste?

Wasteprofile@operationallevel

Capitalinvestmentcost Costofproducedenergy Costperinstallation

Paybackfortypicalinvestor

Politicalcommitment Internationalarena Politicallandscape InvestmentsupportTechnologicalRegime InfrastructureLifespan Maturityoftechnology SocialAcceptability

ResourceOutlookResourceremaining@currentusage

Theoreticalresourceavailability

Levelofnewuptake/annum

PublicOpinion Nationalpublicsupport PublicsupportmonitoringAcceptanceoftechnology

ConsumerBehaviourNationalenergyprogramme

Energybehaviouralchangemonitoring Levelofnewuptake

Table2showsthefirststageof‘filtering’appliedtothefulllistofidealindicators,demonstratingtheselectionofthoseindicatorsdeemedmostsuitableforthepurposesofD2.2.Atthisstageofanalysis,practicalconsiderationssuchasdataavailability,abilitytoconciselycommunicateindicatorsandreplicabilityacrosstechnologieswereincorporated.Subsequenttothis,certainKPI’swerefavouredforparticulartechnologiesandenergysupplychainstages.WhileastandardisedandconsistentapproachwashighlyvaluedintheKPIdevelopmentprocess,anelementofKPIdifferentiationwasnowrequiredatthispoint,duetotheparticularcharacteristicsofeachtechnologycategoryanalysed.TechnologyspecificKPIswereselectedatthisstep,deemedmostcompatiblewiththetechnologyinquestionandbestsuitedtoperformvaluecomparisonswereselectedatthisstep.



Table 2: Framework of Selected Key Performance Indicators to Characterise Energy Supply ChainsTheme StrategicLevelIndicators TacticalLevelIndicators OperationalLevelIndicatorsGreenhousegas GHGprofile@operationallevel

indicators Tonnes GHG per unit of fuel/energyproduced

Environmentalimpact Impactlevel Typeofimpact

indicators High-Medium-Low Hazardouswaste,landscapeimpact,noise,visualimpact,etc.

Capitalinvestmentcost Costofproducedenergy indicators Levelisedenergycosts(LEC) Politicalcommitment Investmentsupportindicators AvailableGrants&PolicySupportTechnologicalRegime InfrastructureLifespan Maturityoftechnology indicators years/infrastructure yearssinceemergence ResourceOutlook Resourceremaining@currentlevelsofusage indicators Yearsworldwide PublicOpinion Nationalpublicsupport Publicsupportmonitoring

indicators Degreeofacceptanceofthetechnology(high-medium-low)

% change of acceptance during lastyears(growing-stable-decreasing)

This firsttablehasbeenusedasabasereferenceandmodified inordertobetteraddresseachsupplychaintechnologyparticularities.Table3showsthefinalguidelinesdefinedforEnergyproduction,storage,andtransportation&distribution.



Table3:KeyPerformanceIndicatorsforproduction,Transportation-DistributionandStoragephases

Theme Production Transportation-Distribution StorageEnvironmentalimpact

GHG profile / Other majortypeofimpact Majortypeofimpact Majortypeofimpact

indicatorsTonnes GHG per unit offuel/energyproduced/Impactlevel

Impactlevel Impactlevel

Capital investmentcost Technologyprice Technologyprice Technologyprice

indicators Levelisedenergycost(LEC) €/km-installation Levelised cost of storedenergy–installation

Performanceindex Efficiency in energytransformation

Efficiency in energytransformation Capacity

indicators Outputenergy/Inputenergy Energy carried/(carried +consumed+losses)

Resource outlook /Flexibility

Resource remaining @currentlevelofusage Technologyflexibility Technologyflexibility

indicators Yearsworldwide AbilitytoreachdifferentlocationsPossibility to installfacilities in differentlocations

TechnologicalRegime InfrastructureLifespan InfrastructureLifespan InfrastructureLifespan

indicators years/infrastructure years/infrastructure years/infrastructureTechnologicalRegime Maturityoftechnology Maturityoftechnology Maturityoftechnology

indicators yearssinceemergence yearssinceemergence yearssinceemergencePoliticalcommitment Policiessupport Policiessupport Policiessupport

indicators Available Grants & PolicySupport AvailableGrants&PolicySupport AvailableGrants&Policy

Support

PublicOpinion National public support &Publicsupportmonitoring

Nationalpublicsupport&Publicsupportmonitoring

National public support& Public supportmonitoring

indicators Degree of acceptance of thetechnology

Degree of acceptance of thetechnology

Degreeof acceptanceofthetechnology

Fortheend-userphaseofanalysis,auniqueKPIsetwasrequired.Aspecificandtailoredcharacterisationthrough bespoke end-user key performance indicatorswas produced. It isworth noting that, as alreadymentionedabove, theend-userstageof thesupplychain iscomprisedofagreatvarietyof technologies,whichservedifferentpurposesindifferentways.ThishasresultedinamorevariegatedandcasespecificdefinitionoftheKPIsusedtoanalyseeachcategoryoftechnologieswithinthisdocument.Themaindefinedthemeshavebeenkeptasacommonguidelinethroughtheentiredocument,whiledifferentKPIshavebeendefined for each specific case. For the sake of simplicity, not all the defined KPIs are presented in thisintroductory chapter, nonetheless, it is still possible to provide a general view of the themes and theapproachimplementedfortheend-usestage.Table4presentstheindicatorsdevelopedandappliedfortheend-userstage,focusingonHVACsystems.Table 5 presents the indicators developed and applied for the end-user stage, focusing on lighting andtransport.



Table4:KeyPerformanceIndicatorsforEnd-userstage–HVACsystems

Theme HVAC(Heating) HVAC(Ventilation) HVAC(AirConditioning)

Environmentalimpact Main type ofenvironmentalimpact

Main type ofenvironmentalimpact

Main type ofenvironmentalimpact

indicators Levelofimpact Levelofimpact Levelofimpact

Capitalinvestmentcost Technologyprice Technologyprice Technologyprice

indicatorsEnd user devicepurchase/installation cost[€/kWh]--payback

End user devicepurchase/installation cost[€/kWh]--Yearsofpayback

End user devicepurchase/installation cost[€/kWh]--Yearsofpayback

Performanceindex Enduserdeviceefficiency Enduserdeviceefficiency Enduserdeviceefficiency

indicators Output energy / Inputenergy

Output energy / Inputenergy

Output energy / Inputenergy

TechnologicalRegime InfrastructureLifespan InfrastructureLifespan InfrastructureLifespanindicators years/infrastructure years/infrastructure years/infrastructureTechnologicalRegime Maturityoftechnology Maturityoftechnology Maturityoftechnologyindicators yearssinceemergence yearssinceemergence yearssinceemergencePoliticalcommitment Policiessupport Policiessupport Policiessupport

indicators Available Grants & PolicySupport

Available Grants & PolicySupport

Available Grants & PolicySupport

PublicOpinion National public support &Publicsupportmonitoring

National public support &Publicsupportmonitoring

National public support &Publicsupportmonitoring

indicators

Degreeofacceptanceofthetechnology, increaseof thepurchasing (high-medium-low/growing-stable-decreasing)



Table 5: Key Performance Indicators for End-user stage – Lighting and Transport systems

Theme Lighting Transport

Environmentalimpact Presence of toxic material requiringdisposal Pollutinggasemission

indicators Yes/No KgofCO2/distanceCapitalinvestmentcost Technologyprice Technologyprice

indicators End user device purchase/installationinvestment[€/kWh]

End user device purchase/installationinvestment[€/kWh]--Yearsofpayback

Performanceindex Enduserdeviceefficiency Enduserdeviceefficiencyindicators EnergyUse(MJ/20millionlumen-hrs) Costof100kmTechnologicalRegime InfrastructureLifespan InfrastructureLifespanindicators Hoursoflifetime yearsTechnologicalRegime Maturityoftechnology Maturityoftechnologyindicators yearssinceemergence yearssinceemergencePoliticalcommitment Investmentsupport Investmentsupportindicators PolicySupport AvailableGrants&PolicySupport

PublicOpinion Nationalpublicsupport&Publicsupportmonitoring


indicatorsMarket share, increase of the purchasing(high-medium-low/growing-stable-decreasing)

Market share, increaseof thepurchasing(high-medium-low/growing-stable-decreasing)



3.4 KPIsevaluationprocessGiventhewidefieldcoveredbytheresearch,thegreatnumberoftechnologiesanalysedandthedifferentthemesconsideredinthedefinitionoftheKPIs,thedataresearchandfinalevaluationprocesshasproved

tobeacomplexone.Uniformityisneededamongthepresenteddataforalltheselectedtechnologies,

sincetheaimofthisevaluationistocomparetheperformancesandpeculiaritiesofdifferenttechnological

solutions.

Existingliteratureperformingsuchanextensivecomparisonoversuchawiderangeoftechnological

solutionisalmostentirelyabsent,howeveritispossibletofindmorespecificstudiesonasingletechnology

oramorelimitedcomparisonoffewertechnologies.Whenanextensivecharacterisationoftheenergy

supplychainisperformed,mostofthetimeeachtechnologyisanalysedbyitself,withoutperformingaglobalcomparison,asinthecaseoftheIEATechnologyroadmaps.

Forthisreason,theevaluationprocesshasresultedinthecollectionofextensivedatafrommanydifferent

sources,andthereportedvaluesarerepresentativeofameanvaluebetweenthevarioussources.Thisisparticularlytrueforless-technicaldata,suchasestimatesofthemostsignificantenvironmentalimpacts,

grantsandpolicysupports,andpublicopinion.Inparticular,publicopinionstatisticswereextremely

difficulttofind,especiallyfortransportorstoragetechnologies,asthemediaandresearchattentionis

mainlyfocusedonelectricalpowerproduction.GiventheselimitationstheassessmentoftheKPIofpublicopinionhasbeenproducedbyevaluatinganumberofdifferentparameterssuchas:

• Primaryenergysource:asstatisticaldataonpublicopinionforenergyproductionareavailable,thetypeofprimaryenergythatthetechnologyusescanbetakenasanindicatorofpublicopinion.

• Marketshare:Especiallyfortheenduser,marketshareisastrongindicatorofhowmanypeopleareinfavourofthattechnology.

• Protestmovements:Fortransportationandstoragetechnologies,thepresenceofprotestsagainstnewinstallationshasbeenconsideredasanegativeindicatorofpublicacceptance.

Thefinalevaluation,publicopinion,cannotbedefinedwithaprecisevalueduetothelackofconsistent

andofficialdata,andsohasbeendefinedbygivingavalueonascalefrom1to5(Low,Low-Medium,Medium,Medium-High,High).

Forthesakeofsimplicity,theKPIstablesrepresentfunctionalgroupsoftechnologiesanddonotprovide

dataforeverysingletechnologydescribed.ThereadercanmakeuseoftheKPIstablestohavean

immediateandclearcomparisonbetweendifferenttechnicalenergysolutions,withamoredetaileddescriptionprovidedineachspecifictechnologysection.Herethedifferentexistingapproachesare

presentedanddetaileddescribingwhatmakesthemdifferent,theirspecificapproach,andwhattheyare

mostsuitablefor.InordertobetteraddressthegeneraltargetoftheKPIstables,oftenarangeofvaluesareproposedtothereader(e.g.efficiencyvalueof15-30%),representingthevariationbetweentheleast,andthemost,performingsolution.Forsomeparticularcases,twodifferentvaluesareproposedforasingle

KPI,clearlyindicatingtowhichtechnologytheyrefer.



ThesourcesusedforcompletingtheKPIstablesarethesameasthosereferencedinthedescription

sections,unlessspecifieddifferently.

4 Energyproduction

Figure3:Productionofprimaryenergy,EU-28,2013(Eurostat,2015b)

PrimaryenergyproductionintheEU-28isspreadacrossarangeofdifferentenergysources.Eurostatdata

from2013showthatthemostimportantprimaryenergysource,intermsofthesizeofitscontribution,wasnuclearenergy(28.7%ofthetotal).ClosetoonequarteroftheEU-28’stotalproductionofprimary

energywasaccountedforbyrenewableenergysources(24.3%),withapredominanceofBiomassand

wasteamongthem.Overall,renewablesourcesexperiencedafastgrowthovertheperiod2003-2013,with

anincreaseof88.4%.Theshareforsolidfuels(19.7%,largelycoal)wasjustbelowonefifthandthesharefornaturalgaswassomewhatlower(16.7%).Crudeoil(9.1%)wastheonlyothermajorsourceofprimary

energyproduction.Withanoppositetrendwithrespecttorenewableenergies,theproductionofother

primarysourcesgenerallydecreasedinthisperiod,mainlyforcrudeoil(-54%),naturalgas(-34.6%)and

solidfuels(-24.9%).

4.1 ElectricityWhenconsideringonlyelectricalenergyproduction,morethanonequarterofthenetelectricitygeneratedintheEU-28in2013camefromnuclearpowerplants(26.8%),whilealmostdoublethisshare(49.8%)camefrompowerstationsusingcombustiblefuelssuchasnaturalgas,coalandoil(Eurostat,2016).Figure4clearlyshowsthegreatpredominanceofnuclearandfossilfuelsintheEuropeanenergymix.

Naturalgas17%

Crudeoil9%

Solidfuels20%

Nuclearenergy28%

Other1%

Renewableenergiy25%

EnergyproductioninEU

Geothermalenergy Solarenergy Wind Hydropower Biomassandwaste



Figure4:Netelectricitygeneration,EU-28,2013(Eurostat,2015b)

ThisdataisadirectrepresentationofhowthecurrentEuropeanenergysystemisstronglycharacterisedbyacentralisedproductionofelectricity.Bigfossilfuelled,nuclearandhydroelectricpowerplantproduceelectricityinspecificrestrictedareasandsubsequenttransportanddistributionisessentialtoprovideelectricalenergytothewholeterritory.Lookingatthetraditionalpowerplants(fossilfuelled,nuclearandhydroelectric)installedinEurope,itisevidenthowcentralgenerationhaveecentralroleintheEuropeanenergyproductionsystem(Hansen,2001).

FollowingthegrowingconcerntowardsenvironmentalproblemsandGHGemissionintheatmosphere,renewableenergyhasbeenstronglypromotedinEuropeduringthelastdecades.Amongtherenewableenergysources,thehighestshareofnetelectricitygenerationin2013wasfromhydropowerplants(12.8%),followedbywindturbines(7.5%)andsolarpower(2.7%)(Eurostat,2016).

TherelativeimportanceofrenewableenergysourcesinrelationtoEU-28netelectricitygenerationgrewbetween2003and2013from12.6%to23.2%,whiletherewasarelativelysmalldecreaseintherelativeimportanceofcombustiblefuelsfrom56.4%to49.8%andalargerreductionintheamountofelectricitygeneratedfromnuclearpowerplantsfrom30.9%to26.8%.Amongtherenewableenergysources,theproportionofnetelectricitygeneratedfromsolarandwindincreasedgreatly:from0.01%in2003to2.7%in2013forsolarpowerandfrom1.4%in2003to7.5%in2013forwindturbines(Eurostat,2016).

Thefastgrowthofrenewablesisresultinginanimportantchangeintheenergygenerationanddistributionsystem,duetothedifferentnatureofmostrenewableenergytechnologieswithrespecttotraditionalfossilfuels,withandincreasingpopularityofDistributedGeneration(DG).

DGischaracterisedbyavarietyofenergyproductiontechnologiesintegratedintotheelectricitysupplysystem,andtheabilityofdifferentsegmentsofthegridtooperateautonomously.

Energysystemscanbemademorerobustbydecentralisingbothpowergenerationandcontrol,resultinginanimprovedprotectionoftheconsumersagainstpowerinterruptionsandblackouts,whethercausedbytechnicalfaults,naturaldisastersorterrorism.Itislikelyinthefuturethatmanyconsumerswillhaveintelligentenergymanagementsystemsbasedontwo-waycommunicationwithenergysuppliers,butimprovementsinthisdirectionstillneedtobedoneatEuropeanlevel.

DistributedGenerationcanprovidedifferentadvantageswithrespecttothetraditionalCentralisedGeneration(IEA,2012):

Combustiblefuels49.8%

Nuclear26.8%

Hydro12.8%

Wind7.5%

Solar2.7%

Geothermal0.2% Other

0.1%

NetelectricitygenerationinEU,2013



• GHGemissionsreduction:DGisbasedonastrongimplementationofsmallscalerenewableenergies,inparticularwindandsolar,whichcanguaranteelowtoalmostnullairpollution.

• Improvedsecurity:Thepresenceofmanydifferentgenerationpointsinterconnectedonthesamegridalloweasilyovercomingfailuresandavoidingblackouts.

• Improvedefficiency:Localgenerationofenergyavoidtheenergylossesduetotransportationanddistributionphases,whichusuallyrangearound10%.

• Reducedfinalcosts:Consumerscanprovidetheirownenergy,savingtransmissionanddistributioncosts,whichcanaccountforupto30%ofthefinalenergyprice.Theycanalsosellelectricitybacktothegridwhentheirproductionexceedstheirdemand,resultinginaconsistentreductionoftheenergybill

Ontheotherhand,thepathtoacorrectDGimplementationisnotstraightforward.Theelectricalgridneedstobeamplifiedandupgradedtoallowfrequentelectricitydirectionreversion,duetothestrongvariabilityofwindandsolar,andbiginvestmentareneededtoperformthisrestructuration.Moreover,smallscalegenerationdonotalwaysresultinareducedenvironmentalimpact;whenusingthesameenergysource,bigplantcanreachhigherefficienciesthanindividualsolutions,resultinginanoverallcleanersystem.

DGisgoingtohaveacentralroleintheEuropeanenergysysteminthenearfuture,butagoodcoordinationwithcentraldistributionisneeded,atleastforthenextdecade.TheincreasinguseofnaturalgasinsteadofcoalincombinationwithCarbonCaptureandStoragetechnologies,whicharethoughstillfarfromcommercialisation,willcontributetodecreasetheGHGemissionsoftraditionalplants,whilemaintainingastrongbasetoaddresstheenergydemandandprovideback-uptovariablerenewableenergies.

4.1.1 CoalCoalhasthelargestshareamongfossilfuelsforelectricitygeneration.In2013theamountofelectricityproducedincoalfiredpowerplantswasthe26.7%ofthetotalEuropeanproduction(Eurostat,2016),secondonlytoNuclearpower.Thisisduetothefactthat,eventhoughEUisgoingtowardsacarbonfreefuture,coalremainsnowadaysaveryreliableandcheapwaytoproduceelectricity.ItisalsoimportanttonoticethatcoaldepositsarepresentinEuropeaswell,makingcoalanevenmoreeconomicallyattractivesolution,sinceithelpsreducingtheenergyimportdependencyofmanyEuropeanCountries.

Coalfiredpowerplantshave,ontheotherhand,severalnegativeimpactontheenvironment(Lako,2010):

• GHGemissions:Firingcoaltogeneratepowerproducesalargeamountofgreenhousegases.Coalplantsaretheprimarycauseofglobalwarming,withatypicalplantgeneratingaround3.5milliontonsof!"#inayear.

• Coalstorage:Coalburnedbypowerplantsistypicallystoredonsiteinuncoveredpiles.Dustblownfromcoalheapsirritatesthelungsandoftensettlesonnearbyhousesandyards.Rainfallcreatesrunofffromcoalheaps.Thisrunoffcontainspollutantsthatcancontaminatelandandwater.

• Waterpollution:Inthesamewayasotherconventionalsteamtechnologies,coal-firedplantsrequirelargeamountsofwaterforsteamandcooling,andcannegativelyaffectlocalwaterresourcesandaquaticecosystem.

• Coalmining:Surfacecoalmininghaveastrongimpact,dramaticallyalteringthelandscape,whileundergroundminingisoneofthemosthazardousofoccupations,killingandinjuringmanyinaccidents,andcausingchronichealthproblems.



4.1.1.1 Pulverised Coal combustion (PCC) power plants

PulverisedCoal(PC)combustionisthetechnologymostwidelyusedtodayforpowergeneration.Thousandsofunitsexistworldwide,accountingforwellover90%oftotalcoalfiredcapacity.DifferentcoalscanbeburnedinPC,butthistechnologymaynotbebestforcoalswithhighashcontent.

Thecoaliscrushedandmilledtoafinepowderandblownintotheboiler,whereitisburned.Theheatproducedintheboilergeneratessteam,whichisusedtodriveasteamturbineandgenerateelectricity.

Grindingthecoalintopowderincreasesitssurfacearea,whichhelpsittoburnfasterandhotterandreducingwaste.Excessairisrequiredtoobtainascompleteaspossiblecombustionofthecarbon(>99%),butmoderndesignsaresuchtocontrolandstagetheadditionofairinordertominimisetheformationofNOx.However,ade-NOxplantmaystillbenecessarytocomplywithenvironmentalrequirements(VV.AA.,2004).

Burningcoalgeneratesash,whichisremovedandisusuallysoldtothebuildingindustry,whereitisusedasaningredientinvariousbuildingmaterials,likeconcrete.Theexhaustgasesarefilteredintheexhauststack,beforebeingemittedintotheatmosphere.Theexhauststacksofcoalpowerstationsarebuilttallsothattheexhaustplumecandispersebeforeittouchestheground.Thisensuresthatitdoesnotaffectthequalityoftheairaroundthestation.

Super-criticalpulverisedcoal(SCPC)powerplantsusesupercritical1steamastheprocessfluidtoreachhightemperaturesandpressures,andefficienciesupto46%(lowerheatingvalue,LHV).Newultrasupercritical(U-SCPC)powerplantsmayreachevenhighertemperaturesandpressure,withefficiencyupto50%.

4.1.1.2 Integrated gasification combined cycles (IGCC)

Inintegratedgasificationcombinedcycles(IGCC)athermo-chemicalreactionwithoxygenandsteamisusedtoconvertcoal(orliquidfossilfuels)intoahigh-pressuresyngasconsistingofcarbonmonoxide(CO),hydrogen(H2),andcarbondioxide(!"#),withsmallamountsofhydrogensulphide(H2S).Afterbeingfilteredtoremoveimpurities,thegasisfiredinagasturbineandsuperheatedsteamisgeneratedwiththeexhaustgasintheheatrecoverysteamgenerator(HRSG),whichdrivesaconventionalsteamturbineandproduceselectricityinaconnectedsecondgenerator.Theuseoftwothermodynamiccyclesincascade(fromwhichthenameof"combinedcycle")allowsgasification-basedpowersystemstoachievehighpowergenerationefficiencies,withvaluesratingfrom39%to45%(Lako,2010).

4.1.2 OilEventhoughithasapplicationinalmosteveryaspectofourlife,oilisnotusedsomuchinelectricitygenerationinEurope.In2013,only1.9%oftotalelectricalproductioncamefromoilfiredpowerplantsandthispercentageisdecreasing(Eurostat,2016).Thishappensbecauseoilismoreexpensivethancoal,whilehavingsimilarperformancesandenvironmentalimpacts.

Burningoiltogenerateelectricityproducessignificantairpollutionintheformsofnitrogenoxides,and,dependingonthesulphurcontentoftheoil,sulphurdioxideandparticulates.Similartocoal-firedplants,pollutedwaterusedintheprocesscanbereinsertedintheenvironment.Sludgeandoilresiduesthatarenotconsumedduringcombustionrepresentatoxicandhazardouswaste.

Drillingnotonlycancauseseriousgeologicalproblems,butalsoproducesalonglistofairpollutants,affectingthehealthandsafetyofworkersandecosystem.Refineries,too,spewpollutionintotheair,waterandland(intheformofhazardouswastes).Oiltransportationaccidentscanresultincatastrophicdamagekillingthousandsoffish,birds,otherwildlife,plantsandsoil.



4.1.2.1 Oil-fired power plants

Oil-firedpowerplantsworkinawaysimilartocoal-firedones.Themaindifferenceoccursatthebeginningoftheplantprocess,sincetheoilcanbedirectlypumpedintheboiler,whilethecoalneededtobecrushedandmilledfirst(EDFEnergy,2016a).

Themaintypesofoil-firedpowerplantsare:

• Conventionalsteam:Oilisburnedtoheatwater,creatingsteamthatdrivesasteamturbinetogenerateelectricity.

• Combustionturbine:Oilisburnedunderpressuretoproducehotexhaustgases,whichdirectlyspinaturbinetogenerateelectricity.

• Combined-cycletechnology:Oilisfirstcombustedinacombustionturbine,usingtheheatedexhaustgasestogenerateelectricity.Aftertheseexhaustgasesarerecovered,theyheatwaterinaboiler,creatingsteamtodriveasecondturbine

4.1.3 GasNaturalgasisthecleanestenergysourceamongthefossilfuelsandthesecondmostusedaftercoal.In2013,the16.6%ofthetotalEuropeanelectricityproductionwasobtainedfromnaturalgaspowerplants(Eurostat,2016).

Overthelastfewdecades,impressiveadvancementintechnologyhasallowedasignificantincreaseofnaturalgasplantefficiency,withsimultaneousreductionofinvestmentcostsandGHGemissions.Electricalefficiencyofnewplantsisexpectedtoincreaseupto64%by2020(Seebregts,2010).Oneoftheadvantagesofnaturalgasplantsisflexibilityandafastresponsetoelectricitydemandchanges.Ingeneral,theyhavelowerinvestmentcostsandhigherfuelcostwithrespecttocoal-firedpowerplants,andtheoveralleconomicaspectsmakecoalamoreconvenientchoice.Nonetheless,naturalgashaslowerGHGemissions,bettermeetingH2020targets,and,thanksalsotothereductionofgaspricesinrecentyears,isgraduallyreplacingcoalinelectricityproductioninEurope.

Inparticular,someoftheadvantagesofnaturalgaswithrespectofcoalare:

• LowerGHGemissions:Combustionofnaturalgas,usedinthegenerationofelectricity,industrialboilers,andotherapplications,emitslowerlevelsofNOx,CO2,andparticulateemissions,andvirtuallynoSO2andmercuryemissions.

• Sludgereduction:NaturalgasemitsextremelylowlevelsofSO2,eliminatingtheneedforscrubbers,andreducingtheamountsofsludgeassociatedwithpowerplantsandindustrialprocesses.

• Cogeneration:Naturalgasisthepreferredchoicefornewcogenerationapplications.

• Higherefficiency:Naturalgasplantscanreachhigherefficiencythancoal-firedpowerplants,upto60%against48%(Seebregts,2010).

Evenifcleanerthantheotherfossilfuels,naturalgasstillhasanegativeimpactontheenvironment.Theprinciplegreenhousegasesemittedincludewatervapour,carbondioxide,methane,nitrogenoxides,andsomeengineeredchemicalssuchaschlorofluorocarbons.Whilemostofthesegasesoccurintheatmospherenaturally,levelshavebeenincreasingduetothewidespreadburningoffossilfuelsbygrowinghumanpopulations.Oneissuethathasarisenwithrespecttonaturalgasandthegreenhouseeffectisthefactthatmethane,theprinciplecomponentofnaturalgas,isitselfapotentgreenhousegas.Methanehasanabilitytotrapheatalmost21timesmoreeffectivelythancarbondioxide.



4.1.3.1 Open cycle gas turbines (OCGT)

Opencyclegasturbines(OCGT)forelectricitygenerationconsistbasicallyofanaircompressorandagasturbinealignedonasingleshaftconnectedtoanelectricitygenerator.Naturalgasispumpedintothegasturbine,whereitismixedwithairandburned,generatingheat.Burningnaturalgasproducesamixtureofgasescalledthecombustiongas,which,expandedbyheat,movetothegasturbine,providingtheneededpowertomakeitspinandmechanicalelectricity.Thismechanicalenergyisthenconvertedintoelectricity.

Almosttwo-thirdsofthegrosspoweroutputofthegas-turbineisneededtocompressair,andtheremainingone-thirddrivestheelectricitygenerator,resultinginarelativelylowelectricalefficiency,rangingbetween35%and42%(Seebregts,2010).

4.1.3.2 Combined-cycle gas turbines (CCGT)

Combined-cyclegasturbines(CCGT)isnowadaysthestandardtechnologyfornewbuiltgas-firedpowerplants.CCGTplantsconsistofcompressor/gas-turbinegroups–thesameastheOCGTplants–butinsteadofdischarginghotgas-turbineexhaustintotheatmosphere,theyarere-usedinaheatrecoverysteamgenerator(HRSG).Here,waterisheatedtogeneratesteamthatdrivesasteam-turbinegeneratorandproducesadditionalpower.Gas-turbineexhaustsarethendischargedintotheatmosphereatabout90°C.StandardCCGTplantscommonlyconsistofonegasturbineandonesteamturbine,whilelargeplantsmayhavemorethanonegasturbine.Approximatelytwothirdsofthetotalpowerisgeneratedbythegasturbineandone-thirdbythesteamturbine.Atfull-load,CCGTcanreachelectricefficiencyupto60%(VV.AA.,2004).

CCGTisamaturetechnology,withmanyCCGTplantsbuiltallovertheworldinthelast10-15years.Itisoneofthedominantoptionsforbothintermediate-load(2000to5000hrs/yr)orbase-load(>5000hrs/yr)electricitygeneration(Seebregts,2010).

4.1.4 NuclearenergyNuclearpoweristhesinglemostusedenergysourceforelectricityproductioninEurope.In2013,26.8%ofthetotalelectricityproducedinEuropecamefromnuclearpowerplant(Eurostat,2016).Itisoneofthecleanestwayofproducingelectricity,withalmostnoGHGemissions,muchlessthanmostrenewableenergiesandsecondonlytowind.TheuseofnuclearpowerplantscanalsorepresentapowerfulmeantoimproveenergyindependenceofaCountry,reducingtheneedforfossilfuelimportation.Thisisthecase,forexample,ofFrance,whichhasastrongbaseofnuclearpowerplantsinitsownterritory.

Theadvantageofnuclearpowerwithrespecttorenewabletechnologiesisthatitisacontinuoussourceofenergy,unlikesunandwind,andcanallowfortheproductionoflargeamountofelectricityinordertocoverthenationaldemand.

Ontheotherside,nuclearpowerpresentsomeverystrongdrawbacks,suchasthecreationoflong-lastingradioactivewastes,whichrequirehundredsofthousandsofyearstodisappear,andthecatastrophicriskpotentialifnuclearfuelcontainmentfails.DisasterssuchasChernobylin1986orFukushimain2011haveshockedthepublic,whichisnowafraidofnuclearpower.

Itisclearhownuclearpowerisacontroversialtechnology,providingatthesametimehighadvantagesandpotentiallycatastrophicdisadvantages.Inrecentyears,importantEuropeancountries,suchasFranceandGermany,havestartedaprogramofnuclearpowerabandoning,followingtherisingoppositionofpublicopinion.

4.1.4.1 Nuclear fission power plant

Anuclearpowerstationmakesuseofthenuclearenergyinuraniumatomstogenerateelectricity.Thecorepartoftheplantisthereactorvessel:thisisatoughsteelcapsulewheretheuraniumisstoredasrodsinto



metalcylinders.Whenaneutronhitsauraniumatom,theatomsometimessplits,releasingtwoorthreemoreneutrons.Thisprocess,calledfission,releaseagreatamountofheatenergy.Thefissionprocessisacceleratedhavingthefuelassembliesarrangedinsuchawaythattheneutronsreleasedbyanatomofuraniumarelikelytohitotheratomsandmakethemsplitaswell.

Theheatgeneratedbythefissionreactionisexchangedwithhigh-pressurewater,sincewaterneedstostayinliquidformforthepowerstationtowork.Thispressurisedwater,withatemperaturearound300°C,ismovedfromthereactorvesseltothesteamgenerator,whereitexchangeheatwithanothercircuitoflowerpressurewater.Duetothemuchlesspressure,waterinthissecondcircuitisevaporatedandsteamthenpassesthroughaseriesofturbinesinordertogeneratemechanicalenergythatwillbeconvertedtoelectricity.Thethermalefficiencyofaconventionalnuclearpowerstationisaround33%.

Nuclearpowerstationsrequiresignificantinvestmenttoconstruct,duetothehighleveloftechnologyandhighsecuritystandardsrequired,buttheirrelativelylowrunningcostsoveralongoperationallifemakethemoneofthemostcost-effectivesolutionsforelectricityproduction.

Asalreadysaid,nuclearpowerhasoneofthesmallestcarbonfootprintsofanyenergysource,withthemajorityof!"#emissionscomingfromconstructionandfuelprocessingphases,notduringelectricitygeneration(EDFenergy,n.a.).

4.1.4.2 Fusion power

Nuclearfusionisoneofthemostpromisingoptionsforgeneratinglargeamountsofcarbon-freeenergyinthefuture.Itistheprocessthatheatsstars,whereatomicnucleicollidetogetherandreleaseenergyintheformofneutrons.

ThewaythisprocessisreplicatedonEarthtoproduceenergyisbyfusinglightatomssuchashydrogenatextremelyelevatedpressuresandhightemperatures(100milliondegreesCelsius).Onepromisingwaytoachievesuchextremeconditionsisaparticulartechniquecalled‘magneticconfinement',whereextremelyhotgasintheformofplasmaiscontrolledwithstrongmagnets.

Powerstationsusingfusionwouldhaveanumberofadvantages:

• Nocarbonemissions:Fusionreactionsonlyemitsmallamountsofhelium,whichisaninertgasthatwillnotaddtoatmosphericpollution.

• Abundantfuels:Deuterium,theelementusedfornuclearfusion,canbeextracteddirectlyfromwaterandtritiumisproducedfromlithium,whichcanbeextractedfromtheearth'scrust.Duetotheeaseofprovision,fuelsuppliesarealmostunlimited.

• Energyefficiency:Nuclearfusionisanincrediblyefficientprocess.Onekilogramoffusionfuelcanprovidethesameamountofenergyas10millionkilogramsoffossilfuel.

• Nolong-livedradioactivewaste:Differentlyfromnuclearfission,alimitedamountofradioactivewasteisgenerated.Inparticular,onlyplantcomponentsbecomeradioactive.Thesecanberecycledordisposeofconventionallywithin100years.

• Safety:Sinceonlyaverysmallamountsoffuelisusedinfusiondevicesalarge-scalenuclearaccidentisnotpossible.

• Reliablepower:Inthesamewayasnuclearfissionplants,fusionpowerplantscangenerateelectricityincontinuousandcontrolledway,atcostssimilartoothertraditionalenergysources.Nuclearfissioncanthereforebecomeanexcellentsolutiontorenewableenergiesvariability.



Nuclearfusioniscurrentlyatanexperimentalphase.TheInternationalThermonuclearExperimentalReactor(ITER)isanexperimentalfusionreactorinthesouthofFranceaimingtodemonstratethefeasibilityoffusionasaviablesourceofenergy(CulhamCentreforFusionEnergy,2012).

4.1.5 KPIsevaluationfornon-renewableenergiesInthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthenon-renewableenergyproductiontechnologiesintroducedintheprevioussectionisproposed.Ithelpsgivingaclearandsimpleunderstandingofeachtechnologystrengthandweaknesstowardsalowcarbonfuture.

ThemainsourcesthatinformTable6,below,comefromthesamereferencesquotedineachspecifictechnologysection,withtheadditionofLCOE(2014),Schlömeretal.(2014),Shahriar(2008),Lazard(2014),Honorio(2003)andEuropeanCommission(2007).

Table6:KPIsevaluationfornon-renewableenergies

Theme Typeofindicator Coal Oil Gas Nuclear

GHGemissions

Life-cycleemissionslevel

(g!"#%&/kWh)1001 840 469 16

Environmentalimpact

TypeGHG

emissionsGHG

emissionsGHG

emissionsHazardouswaste

Environmentalimpact

Level High HighMedium-high

High

Capitalinvestmentcost

Levelisedenergycost(€/MWh)

66-151€ 297-332€ 102-171€ 92-132€

Performanceindex Efficiency 35-48% 35-45% 32-60% 33-36%

Technologicalregime

Infrastructurelifespan(years)

40 40

20(gasturbine)

40

30-40

Technologicalregime

Maturityoftechnology

Mature Mature Mature Mature

Resourceoutlook

Resourceremaining

worldwide(yearsleftatcurrentusagelevel)

107 35 37 -

Politicalcommitment

AvailableGrants&Policysupport

EnergyRoadmap20502030climate&energyframework



(Eachmemberstateisfreetotakeindividualdecisionsonthemeasurestoreachthesetobjectives)

PublicopinionDegreeof

acceptanceofthetechnology

Low Low Medium Low

Non-renewableenergiesstillrepresentnowadaysthegreatmajorityofsourceofelectricalenergyin

Europe.InordertoreachtheEurope2020targetofa20%reductioninGHGemissions,naturalgasis

increasingitsmarketsharereplacingcoal.Itiswellvisiblefromthetablethatacompletereplacementofcoalwithnaturalgascoulddecreasethepowerplantsemissionsbyhalf,withoutevenconsidering

renewableenergies.Thelowercostofcoaliswhatkeepsitstrongonthemarket.Duetoanenvironmental

impactandperformancessimilartocoal,butahigherfuelcost,oilisnotmuchusedasasourceofenergyin

powerplants.Thesituationofnuclearenergy,asalreadysaid,isverycontroversial:itisoneofthetechnologieswiththelowestGHGemissionrateanditsperformancesaresimilartofossilfuels,allowingfor

bigplantsandhighlevelofenergyproduced.Themaindrawbackofnuclearenergyisthehazardouswaste

itproduces,whichisthemostdangerousamongallenergytechnologies.

4.1.6 HydraulicHydropoweristhemostcommonrenewablesourceusedforelectricityproduction,withashareofaround

13%fornetelectricitygenerationatEUlevel.Whenconsideringonlyrenewableenergies,Hydraulicpower

accounts,asof2013,forthe45.5%ofthetotalelectricityproducedinEurope(Eurostat,2016).

Ithasbeenusedsinceancienttimesforseveralapplications,suchasdrivingwatermillsorothermechanical

devices,andinthelate19thcentury,hydropowerbecameasourceforgeneratingelectricity.Todaythe

termisusedalmostexclusivelyinconjunctionwiththedevelopmentofhydroelectricpower.

Thereareseveralwaystogenerateelectricitythroughtheuseofmovingwaterforce,themostknownand

commonbeingariverflowstreamchannelledintoapowerplantturbine.Morerecently,followingthe

needforcleanerandrenewableenergy,improvementshavebeenmadeintideandwaveenergy

conversion.

4.1.6.1 Hydro Electric power plants

4.1.6.1.1 ConventionalimpoundmentThemostcommontypeofhydroelectricpowerplantisanimpoundmentfacility.Animpoundmentfacility,typicallyalargehydropowersystem,usesadamtostoreriverwaterinareservoir.Waterreleasedfrom

thereservoirflowsthroughaturbine,spinningit,whichinturnactivatesageneratortoproduceelectricity.



Figure5:Hydroelectricdamscheme(Tomia,2007)

Thewatermaybereleasedeithertomeetchangingelectricityneedsortomaintainaconstantreservoir

level.

Conventionalimpoundmentpowerplantspresentseveraladvantageswithrespecttofossilfuelones,but

alsosomeimportantdrawback.Inparticular,themainprosare:

• Flexibility:Hydroturbineshaveastart-uptimeoftheorderofafewminutes,muchshorterthan

forgasturbinesorsteamplants.Hydropowerstationscanalsoberampedupanddownveryquicklytoadapttochangingenergydemands.

• Lowpowercosts:Themajoradvantageofhydroelectricityiseliminationofthecostoffuel,makingitsoperatingcostnearlyimmunetoincreasesinthecostoffossilfuelssuchasoil,naturalgasor

coal.Theaveragecostofelectricityfromahydrostationlargerthan10megawattsis3to5euro-

centsperkilowatt-hour(WorldwatchInstitute,2012).Operatinglabourcostisalsousuallylow,asplantsareautomatedandhavefewpersonnelonsiteduringnormaloperation.

• Reducedairandwaterpollution:Sincehydroelectricdamsdonotburnfossilfuels,theydonotdirectlyproducegreenhousegases.Alsothewaterpassedthroughtheturbineisguidedbackinto

theriveruncontaminated.

Ontheotherside,themainconsofthistechnologyare:

• Ecosystemdamageandlossofland:Theconstructionoflargedamsresultinsubmersionof

extensiveareas,sometimesdestroyingbiologicallyrichecosystems,andcausinglanderosion.Thedownstreamriverenvironmentcanbealteredaswell,sincethewaterexitingaturbineusually

containsverylittlesuspendedsediment,whichcanresultinscouringofriverbedsandlossof

riverbanks.



• Siltationandflowshortage:Heavyparticles,transportedbythewaterflow,tendtoaccumulateinthereservoir.Siltationcanfillareservoirandreduceitscapacitytocontrolfloodsalongwith

causingadditionalhorizontalpressureontheupstreamportionofthedam.

• Relocation:Duetothesubmergingofawideareawhichwaspreviouslyhabitable,allthepeoplelivingwherethereservoirsareplannedneedtoberelocated.

• Failurerisks:Duetothehugeamountofwaterconfinedinareservoir,failuresduetopoorconstructionornaturaldisasterscanhavecatastrophicconsequences.Damfailureshavebeen

someofthelargestman-madedisastersinhistory.

Asof2015,thelargesthydroelectricpowerstationistheThreeGorgesDaminChina,withagenerating

capacityof22500MW(NewsXinhuanet,2015).Overall,thankstothegreatpowergeneratedbyfalling

waterandthehighenergytransformationefficiency,hydropowerissuitableforlargepowerplant,

accountingforthefivelargestpowerstationsintheworld,intermsofcurrentinstalledelectricalcapacity.

4.1.6.1.2 Run-of-the-riverhydroelectricityRun-of-the-river(ROR)hydroelectricityisatypeofhydroelectricgenerationplantwherebylittleornowaterstorageisprovidedandis,therefore,subjecttoseasonalriverflows.Onlyasmalldamisusuallybuilt

toensurethatenoughwaterentersthepenstockpipesthatleadtotheturbines.Thistechnologyiswell

suitedforstreamsthatcannaturallysustainaminimumflowthroughoutthewholeyears.

Whendevelopedwithcaretofootprintsizeandlocation,RORhydroprojectscancreatesustainableenergyminimisingimpactstothesurroundingenvironmentandnearbycommunities.Itstillpossessestheabilityto

producecleanenergywithnoGHGemissions,whileatthesametimeavoidingmanyofthenegative

impactsthatdamshaveonthelandscapeandecosystem.

Ontheotherside,theplantwilloperateasanintermittentenergysource,highlydependentonseasonalflowandwithnopossibilitytofollowtheenergydemand.Moreover,evenifittruethatRORhavea

reducedimpactontheecosystem,itisnoteasytofindgoodareasfortheirimplementationandlarge

plantsstillpresentenvironmentalconcerns,duetotheirdimensions.

4.1.6.1.3 Pumped-storageAnothertypeofhydropowercalledpumpedstorageworkslikeabattery,storingtheelectricitygenerated

byotherpowersourceslikesolar,wind,andnuclearforlateruse.Whenthedemandforelectricityislow,apumpedstoragefacilitystoresenergybypumpingwaterfromalowerreservoirtoanupperreservoir.

Duringperiodsofhighelectricaldemand,thewaterisreleasedbacktothelowerreservoirandturnsa

turbine,generatingelectricity(Energy.gov,2016).

4.1.6.2 Tidal power

Tidalpowerisaformofhydropowerthatconvertstheenergyobtainedfromtidesintousefulformsofpower,mainlyelectricity.Oneofthemainadvantagesoftidalpoweristhattidesaremorepredictablethan

otherrenewablesourceslikewindandsolar.

Nowadaystidalenergygeneratorsarenotyetwidelyused,duetoarelativelyhighcostandlimitedavailabilityofsiteswithsufficientlyhightidalrangesorflowvelocities.Thosefactorshavebeenastrong



limittotidalpowergrowth,butthankstorecenttechnologicaldevelopmentsandimprovements,together

withtherenewablenatureoftidepower,thistypeofenergysourcecouldplayanimportantroleinafuture

Europeanlowcarbonenergysystem(Kempener,2014).

4.1.6.2.1 TidalbarrageAtidalbarrageisadam-likestructurethatisbuiltacrossthemouthofariverorbayinordertoharvest

energyfromtheebbandflowoftidesinthelocation.

Atidalbarrageisusuallypositionedatanestuary,bay,river,orotheroceaninletandcontainsgatescalled

sluicesthatcanopenandclose,inordertocontrolthewaterflow.Atlowtide,thegatesopenandallow

thetidetoflowintotheriverasnormalasthetiderises.Whenhightideisreached,thegatesareclosedandpreventthewaterfromretreatingbacktotheoceanasitnormallywould.Instead,thewaterisforced

throughspecificchannelsthatdirectitthroughturbinesinordertoproduceelectricity(Evans,2007).Figure

6showaschematicviewofthisprocess.

Figure6:Tidalbarragescheme

Tidalbarrageisasimpleandmaturetechnologyandisthemostsimilartootherformsofhydroelectricgeneration,astheoneseeninthepreviouschapter,thatinvolveadamtocontrolthewaterflow.

Unfortunately,thereareanumberofdisadvantagestotidalbarragesthathavekeptthemfrombecoming

morepopular.Thefirstdisadvantageiscost.Buildingalargedamacrossthemouthofariverortheinletof

abayismorecomplicatedandcostlythanbuildingadamonariver.

Morethantheeconomicimpact,theenvironmentalimpactoftidalbarragesisaseriousconsiderationin

theirconstruction.Estuaries,rivermouths,andbaysaresensitiveecosystemsthatoftenrepresentthe

spawninggroundsforspeciesthatmaynotbreedanywhereelse.Alteringtheflowofseawaternegatively



affectsanumberofmarinemammalsaswellasfish,crustacean,andplantlife(RenewableNorthwest

Project,2006).

4.1.6.2.2 TidalstreamgeneratorsTidalStreamGenerators(alsocalledTidalEnergyConverters)aresimplemachinesthatextractenergyfrom

themovementofwaterwiththetides.Thenamederivesfromthefactthatthemachinesareplacedinthe

pathofthetide,calledthetidalstream.Theyarethecheapestandmostcommontypeelectricitygenerationfromtidalpower.

Certaintypesofthesemachinesfunctionverymuchlikeunderwaterwindturbines,andarethusoften

referredtoastidalturbines.Infact,tidalstreamgenerationismoresimilartowindenergythanitistohydroelectricpowergeneration.Turbinescomeinmanyshapes,withbothhorizontalandverticalaxis.The

formertypeisthemostcommonlyused,duetoitssimplicity,whilethelatteristobepreferredinsettings

wherethedirectionofthetidalstreamvaries,sinceverticalaxisturbinesdonotneedtobedirected

perfectlyintothestreamofthetide.Manyturbinescanruninbothforwardandreversedirections,inthiswaytakingadvantageofbothphasesofthetide.Sincewateris800timesdenserthanairandthusprovides

morecontactwiththebladesoftherotor,awaterflowrateof2-3meterspersecond(whichisabout

averageinmostplacesexceptatneaptide)wouldtranslateintofourtimesmoreenergyforeveryturnof

theturbineascomparedtowind(TidalPower,n.d.).

Sincetheydonotneedtheconstructionofadamtowork,tidalstreamsgeneratorsareeasyandcheapto

implement,canbeimplementedinalreadyexistingstructuresandtheirmodularityallowssmallsitetobe

easilyexpanded.Ontheotherside,duetothesmallervelocityofstreaminvolved,theygenerallycannot

produceasmuchpowerasbarragesystems.

4.1.6.2.3 DynamicTidalPowerDynamicTidalPowerorDTPisthemostcomplicated,leastwellunderstoodtidalpowerschemeyetconceived.Itmakesuseofthefactthatoceantidesdon’toperatestrictlyperpendiculartotheshore,but

alsoflowinparalleltotheshore.Thisphenomenonisparticularlystronginsomeareas,suchassome

ChineseandnorthernEuropeancosts.Buildingabarrageperpendiculartothecoast,asshowninFigure7,

itwouldbepossibletoharvestenergyfromthistypeoftidesastheyflowparalleltotheshore.



Figure7:DTPscheme(TidalPowerUK,n.d.)

Theredrepresentsrelativehighwaterandbluerepresentsrelativelowwater.Shiftinginthetidedirection,andconsequentlyintheheightsides,usuallyhappensevery12hours.

Thesystemonlyworksifthebarrageisatleast30kilometreslongandonlyiftheturbinesworkinboth

directions.Sofar,thesystemhasbeenprovenintheory,butithasneverbeenputtothetestandthereis

nowaytobecertaintheschemewillreallyworkwithoutexperiments.

Themainadvantageofdynamictidalpoweristhatasingleinstallationcouldproducefrom8to15GWof

power,ordersofmagnitudemorethananyothertidalenergysystem(Kempener,R.,&Neumann,F.2014).

An8GWinstallationcouldgenerateenoughelectricityinayearformorethanthreemillionEuropeans.

Sinceitgeneratespowerinbothtidedirections,DTPisstableandmorecontinuousthanotherformsoftidalenergy.Finally,duetoitslargedimensions,DTPcanbecombinedwithothersolutionsuchaswind

turbines,solarpanels,aquacultureandresearchfacilities,andmore.

ThemaindisadvantagewithDTPisthatthereisnowaytobecertainitwillworkwithoutbuildingafacility,whichisveryexpensive(tensofbillionsofeuros)andpresentsmanyengineeringdifficultiesassociated

withbuildinga30kmdamoutintotheocean.Environmentalimpactscannotbedeterminedaswell

withoutbuildingoneDTPstructure,andblockingalargeportionofcoastalflowmayhaveatremendous

ecologicimpact.

4.1.6.3 Wave power

Wavepowerisgeneratedfromthebobbingmotionofobjectsthatfloatintheocean.Energyfromthewavecrestitselfliftstheobjectagainstgravityendowingitwithpotentialenergy.Whenthewavecrestpasses,

theobjectfallsintothewavetrough,whichtranslatesitsenergyfrompotentialtokinetic.Withamechanicaldeviceitispossibletoconvertthisenergyintoelectricity.



Anothermethodofgeneratingenergyfromwavesinvolvesacombinationofwindandwaterenergy.Water

fromthewaverisesupinsideachamber,thusdisplacingair.This,inturn,pushesasmallfanthatgenerates

electricity.Whenthewaterfalls,airrushesbackintothechamberandturnsthefanonceagain.Suchsystemsaregenerallyonlyfoundinsmall-scaleapplications(RenewableNorthwest,2009).

Theconceptofwaveenergyhasgoodpotential,especiallyduetothefactthatwavesalmostconstantly

providepower,buthasgainedlittleinterestcomparedtootherformsofenergygenerationduetothe

difficultyofmaintainingequipmentandgeneratinglargeenoughquantitiesofelectricityatanaffordableprice.WavefarmsthatareusedfortestingtheconceptofwavepowercanbefoundinPortugal,theUnited

Kingdom,Australia,andtheUnitedStates.Currently,theonlyrealapplicationofwavepowerisinbuoys

thathavelightsorGPStrackingembeddedinthem.

4.1.6.4 Ocean Thermal Energy

Oceanthermalenergyreliesonthedifferenceintemperaturebetweenthecooldeepwateroftheoceanandwarmersurfacewater,providingpowertoaheatengine,whichcaninturnbeusedtogenerate

electricity.Warmoceanwateriseitherallowedtoboilitselforisusedtoboilasecondarylow-boiltemperaturefluid.Thegasthatisgeneratedisusedtoturnaturbineandgenerateelectricityandthen

condensedbacktoliquidbycoldoceanwatersothatthecyclecanrepeatitself.Oceanthermalenergyisa

continuousrenewableenergy,sincedifferenceinoceantemperatureatdifferentdepthsisalwayspresent,

makingitagoodpotentialsolutiontoprovideanelectricalbaseloadwhenothersourcesassolarorwindarenotworking(VV.AA.,2011c:87).

ThemaintechnicalchallengeofOceanthermalenergyconversion(OTEC)istogeneratesignificantamounts

ofpowerefficientlyfromsmalltemperaturedifferences.Moderndesignsallowperformanceapproaching

thetheoreticalmaximumCarnotefficiency.Anotherissueisthatgettingcoldwatertothesurfacerequiresenergy,sosomeoftheenergyproducedfromthesesystemsislost,makingthemnecessarilylessefficient

thanwave,tidal,ortraditionalhydropower.

4.1.7 WindWindpoweristhesecondmostusedrenewableenergysourceforelectricityproduction,withamarket

share,amongrenewables,of26.5%in2013.Between2000and2010theglobalcapacityofwindindustry

hasincreasedanaverageof30%peryear,reaching200GWinstalledin2010,anditisstillgrowingfast

today.2012wasarecordyearfornewonshorewindinstallationswithover46GWofcapacitybuiltintheyear.Offshorewindhashadaslowergrowthduetohigherinstallationandrunningcosts,butitisforeseen

itwillreachnearly50GWofglobalcapacityby2020(Eurostat,2016).Itisnosurprise,then,thatwind

powerisbecominganincreasinglyimportantinmanycountriesaspartofastrategytoreducetheir

relianceonfossilfuelstowardsEU2020objectives.

Themainadvantageofusingwindpoweristhatwindisabundant,inexhaustible,andaffordable,makingit

agoodalternativetofossilfuels.Itisalsooneofthecleanestandmostsustainablewaystogenerate

electricityasitslifecyclegreenhousegasemissions(11.5gCO2eq/kWh)arethelowestamongrenewablesandcomparabletonuclearpowerones.



Ontheotherside,windisnotcontrollablenorpredictable,makingitnecessarytouseitinconjunctionwith

other,morecontrollable,waysofgeneratingelectricity,inordertobeabletoalwayssustainthegrid

energeticdemand.Themainenvironmentalissuerelatedwithwindpoweristurbinessoundandvisualimpact.Somepeoplelivingclosetowindfacilitieshavecomplainedaboutsoundandvibrationissues,

while,whenitcomestoaesthetics,windturbinescanelicitstrongoppositereactions(IEA,2013a).Inany

case,anynewinstallationneedstobediscussedinadvancedwiththelocalcommunities,inordertoavoid

NIMBYreactions.

4.1.7.1 On-shore wind turbines

Windturbinesaredevicesusedtoconvertwindkineticenergyintothemechanicalrotatingenergyandfinallyintoelectricity.Eachwindturbineisastandaloneindependentunit,thisprovidinghighmodularityto

thetechnology.Theycancomeinseveraldimensionsandshapes,allbelongingtotwomainconcepts,horizontalandverticalrotationaxis.Horizontalaxisturbines(withthreeblades)arethemostefficientand

commontype,andhaveadominantshareontoday’smarket,whileverticalaxisones,thoughpresenting

someadvantageswithrespecttotheothertype,arealmostabandoned(IEA,2013a).

4.1.7.2 Off-shore wind turbines

Offshorewindpoweroroffshorewindenergyreferstotheconstructionofwindfarmsoffshoretogenerateelectricityfrommarinewind.Theadvantageofthisapproachisthatwindspeedsaregenerallystronger

offshorecomparedtoonland,sooffshorewindpowercanmanagetoprovideagreateramountofelectricalpower.Inaddition,offshorebreezescanbestrongintheafternoon,matchingthetimewhen

peopleareusingthemostelectricity.Anotherpointinfavourofoffshoreturbinesisthattherisingof

NIMBYoppositiontotheirconstructionisusuallymuchweakerthanwithonshoreones,duetothe

distanceoftheoffshorewindfarmstopeopleactivities.

Whiletheoffshorewindindustryhasgrowndramaticallyoverthelastseveraldecades,especiallyin

Europe,offshorewindfarmsarestillrelativelyexpensive.AccordingtotheUSEnergyInformationAgency,

offshorewindpoweristhemostexpensiveenergygeneratingtechnologybeingconsideredforlargescale

deployment.Pricescanbeintherangeof2.5-3.0million€/MW(EWEA,2015),withtheturbinerepresentingjustonethirdtoonehalfofthecostandtherestcomingfrominfrastructureand

maintenance.

Environmentalimpactofoffshoreturbinesandoftheassociatedinfrastructuresisstillnotcompletelyclearanddiscussionarerisingonhowtheconstructionandoperationofthesewindfarmsaffectthemarine

ecosystem.Commonenvironmentalconcernsinclude:

• Theriskofseabirdsbeingstruckbywindturbineblades

• Theunderwaternoiseassociatedwiththeturbineoperation

• Thephysicalpresenceofoffshorewindfarmsalteringthebehaviourofmarineanimalswithbothpossibilitiesofattractionandavoidance;

• Thepotentialdisruptionofthelocalmarineenvironmentfromlargeoffshorewindprojects.



4.1.7.3 Vortex bladeless

Vortexisanewtechnologycurrentlyunderdevelopment,consistingofawindgeneratorwithoutblades.

Insteadofcapturingenergyviatherotationalmotionofaturbine,theVortextakesadvantageofthesocalled‘vorticity’,anaerodynamiceffectthatoccurswhenwindbreaksagainstasolidstructure.TheVortex

structurestartstooscillate,andcapturesthemechanicalenergythatisproducedtotransformitinto

electricity.AnadvantageofVortextechnologyisthatitisdesignedtohavenopartsincontactatall(no

gears,linkages,etc.)inordertomakeitcheapandeasytomaintain.Thistechnologyshouldbeabletoproduceenergyata40%lowercostthanacomparablewindinstallationand,thankstotheeliminationof

mechanicalelementsthatcansufferwearandtearfromfriction,itisestimatedtoreducemaintenancecost

by80%.

Finally,Vortexissilent,sinceitoscillatesatafrequencythatdoesn'tproduceaudiblenoise(itisbelow20Hz),hassmallerdimensionsthananormalwindturbineandit’salsosaferforbirds,eliminatingthe

possibilityofcollisionwithturbineblades.

Thereducedcostanddimensionsallowforahigherdensityofinstallation,whichcompensatesforalowerefficiencyofenergyconversion(30%less).Computationalmodellingestimatesoperationallifetimeofthe

installationtobebetween32and96years(Indiegogo,2016).

4.1.8 SolarSolarenergyisthemostabundantrenewableenergysourceavailableonEarth.Just18daysofsunshinecontainthesameamountofenergyasalloftheplanet'sreservesofcoal,oil,andnaturalgas.Solarpower

hasincreasedrapidlyitsmarketshareinrecentyearsand,in2013,accountedfor10%ofallrenewable

electricity,2.7%ofthetotalEuropeanelectricityproduction.Also,in2013theelectricitygeneratedfromsolarenergysurpassedwoodandothersolidbiomass,becomingthethirdmostimportantcontributorto

theelectricityproductionfromrenewablesources(Eurostat,2016).

Likewindpower,thesunprovidesatremendousresourceforgeneratingcleanandsustainableelectricity.

Solarpowerdoesnotleadtoanyharmfulemissionsduringoperation,butsomepollutionisgeneratedduringthesolarpanelsproductionphase,makingitalesscleanenergythanwind.

Anotheradvantageofsolarsystemsisthattheycanbebuiltbothinsmallinstallations,toprovideelectricity

forhomes,buildingsandremotepowerneeds(thisisparticularlytrueforpoorregions),andatutility-scale,

toproduceenergyasacentralpowerplant.

Differenttypesofsolarpanelsarepresentonthemarket,havingaverageefficiencyrangingfrom15%to

25%,respectively(Honorio,2003:11).Efficiencyishighlydependentfromtheamountofsunraysthathit

thepanels,andthereforevariesalotdependingonthegeographicalregionandtheperiodoftheyear.This

hasconsequencesalsoonthepaybacktimeofthesystem.InsouthernEurope,thisisapproximately1to2yearsandincreasesathigherlatitudes(IEA,2013d,31).Thisisaveryfastpaybackperiod,consideringan

averagesystemlifeexpectanceof30years.

Theenvironmentalimpactsassociatedwithsolarpowercanincludelanduseandhabitatloss(inparticularforlargesolarplants),wateruse,andtheuseofhazardousmaterialsinpanelsmanufacturing,thoughthe

typesofimpactsvarygreatlydependingonthescaleofthesystemandthetechnologyused.



4.1.8.1 Photovoltaic

Photovoltaicisatechnologythatconvertslightintoelectricalenergythankstoaphotovoltaicsystemcalled

solarcell.Bothaphysicalandchemicalprocesstakeplace,generatinganelectriccurrent.MultiplesolarcellsaremutuallyconnectedinaphotovoltaicmodulethustotalcapacityofPVsystemisincreased.PV

modulesproducedirectcurrent,whichthenneedstobeconvertedintoalternatingcurrentbyaninverter.

TypicalconversionefficienciesforPVmodulescanreachvalesupto20%andover(IEA,2013d,29).

PVsystemcanbeusedasgridconnectedsystems,andasoff-gridsystems.Thesesystemsaremainlyinstalledonroofsandhaverelativelysmallcapacity.Whenavailabletheyareconnectedtothegrid,

especiallyindevelopedcountrieswithlargemarkets,inordertoselltheelectricitywhenproductionexceed

theneeds.BuildingintegratedPVsystemsareagreenandcosteffectivesolution,sincetheyallowon-site

electricitygenerationanddeploymentofunusedroofarea.Incertainapplicationssuchaslighthouses,orindevelopingcountries,exceedingproducedelectricitycanbestoredinbatteriesoradditionalpower

generators,inordertoallowoperationsatnightandatothertimesoflimitedsunlight.Withintroductionof

incentiveschemeforRESelectricityproduction,gridconnectedsystemforelectricitygenerationbecomemainapplicationofPV(IEA,2012d).

4.1.8.2 Concentrated solar power

Concentratingsolarpower(CSP)systemsusemirrorstoconcentratetheenergyfromthesuntodrive

traditionalsteamturbinesorenginesthatcreateelectricity.Themainsolarconcentratingtechnologiesusednowadaysare:

• Parabolic trough: itconsistsofa linearparabolic reflector thatconcentrates lightontoareceiverpositionedalongthereflector'sfocalline.

• Compact Linear Fresnel Reflectors: It’s a system which use many thin mirror strips instead ofparabolicmirrorstoconcentratesunlightontotwotubeswithworkingfluid.

• Stirlingsolardish:itcombinesaparabolicconcentratingdishwithaStirlingenginewhichnormallydrives an electric generator. The advantages of Stirling solar over photovoltaic cells are higherefficiencyofconvertingsunlightintoelectricityandlongerlifetime.

• Solarpowertower:Anarrayoftrackingreflectorsisusedtoconcentratelightonacentralreceiverpositionedatthetopofatower.

Forallofthesetechnologiesitispossibletousevarioustechniquestotrackthesunandfocuslightinasinglepoint,improvingtheoverallsystemefficiency.Theconcentratedsunlightisthenusedtoheata

workingfluid,whichgeneratespowerthroughaturbine(EnergyGov.,2016a).

Environmentalimpactislow,butduetothehighconcentratedheatgeneratedbythistypeoftechnology,

therehasbeennumerousreportsofbirdsinjuredorkilled.

4.1.8.3 Concentrator photovoltaic

Concentratorphotovoltaics(CPV)systemsemploysunlightconcentratedontophotovoltaicsurfacesforthepurposeofelectricalpowerproduction.Theybasicallycombinetogetherphotovoltaicandconcentrating

solarsystems,usinglensesandcurvedmirrorstofocussunlightontosmall,buthighlyefficientsolarcells.Solarconcentratorsareoftenmountedonasolartrackerinordertokeepthefocalpointuponthecellas



thesunmovesacrossthesky.ThissolutioncandrasticallyimproveefficiencyofPV-solarpanels(IEA,

2013d).

Figure8:ConcentratorPVpanel

4.1.8.4 Floatovoltaics

FloatovoltaicsareanemergingformofPVsystemsthatfloatonthesurfaceofwater.Theadvantageofthesesystemsissimilartotheonesofoffshorewind:theyreducetheneedofvaluablelandareaand,as

thepanelsarekeptatacoolertemperaturethantheywouldbeonland,theyallowahigherefficiencyof

solarenergyconversion.Floatovoltaicpanelsalsomakeitpossibletosavedrinkingwaterthatwouldotherwisebelostthroughevaporation.Thisisagreatadvantageforpoorcountrieswithlimitedaccessto

bothcentralisedpoweranddrinkingwater(Energynnovation.it,2016).

4.1.8.5 Fully transparent solar panels

ItconsistsofasolarcellthatabsorbinfraredandUVlight,lettingvisiblelightpassthroughandthereforelookingtransparent.Untilnow,solarcellsofthiskindhavebeenonlypartiallytransparentandusuallyabit

tinted,butaMichiganStateUniversityresearchteamhavemanagedtocreatenewonesthataresoclear

thatthey’repracticallyindistinguishablefromanormalpanelofglass.Thistechnologyiscurrentlyatresearchstage,anditcanachieveonly1%efficiency,butthehopeistoreach10%afterindustrialisationn.

Therangeofpossibleapplicationishuge,suchasforexamplewindowsandsmartphonescreens

(ExtremeTech,2015).

4.1.9 GeothermalGeothermalpowertakeadvantageofthenaturalheatgeneratedfromradioactivedecayinsideEarth.Ithas

beenusedforbathingsincePalaeolithictimesandforspaceheatingsinceancientRomantimes.Nowadays



itisusedforbothelectricityandheatproduction.In2013,0.2%oftotalelectricityinEuropehasbeen

producedthroughgeothermalpower(Eurostat,2016).Thankstotechnologicalimprovement,itispossible

tobuildgeothermalelectricplantsnotonlyonareaswherehightemperaturegeothermalresourcesareavailablenearthesurface,butoveramuchgreatergeographicalrange.

Thethermalefficiencyofgeothermalelectricplantsislow,around10–23%,becausegeothermalfluidsdo

notreachthehightemperaturesofsteamfromboilers.Whenpossible,exhaustheatcanbeusedlocallyto

provideheatingtonearbuildings.Sincetheheatfromgroundisconstantlyavailable,themaineffortsinimprovementsarenotonsystemefficiencybutratheronoperationalcosts,inordertoreducethepayback

period.Geothermalplantsregularlyoperatingat90%ormoreoftheirratedcapacity,beingthereforemost

oftenusedforprovidingbaseloadenergy,increasingsystemreliabilityandloweringoveralloperatingcosts.

Whilenotrequiringanyfueltoproduceheat,geothermalheatingsystemscontainpumpsandcompressors,whichmayconsumeenergyfromapollutingsource.Fluidsdrawnfromthedeepearthcarryamixtureof

gases,notablycarbondioxide(CO2),hydrogensulphide(H2S),methane(CH4)andammonia(NH3).Another

importantenvironmentalimpactofgeothermalpowerisrelativetotheplantconstruction,whendrillingoperationcancausesubsidence,tectonicupliftortriggerearthquakesaspartofhydraulicfracturing(Kagel,

BatesandGawell,2007).

4.1.9.1 Dry steam power station

Drysteamstationsarethesimplestandoldestdesign.Theydirectlyusegeothermalsteamof150°Corgreatertogenerateelectricityfromturbines.Thissolutionisapplicablewhenanaturalunderground

resourceofsteamisavailableatthepropertemperature.Forthisreason,therearenotmanypowerplants

ofthistypeintheworld(IEA,2012b:15).

Figure9:Drysteampowerstationscheme

4.1.9.2 Flash steam power station

Inaflashsteamprocess,waterfromundergroundwellsisseparated(flashed)intosteamandwater.Thewaterisdirectlyreturnedtothegeothermalreservoirbyinjectionwells,whereitcanbeheatedagain,



whilethesteamisusedtodriveaturbineandgenerateelectricity.Afterpassingthroughtheturbine,the

steamiscooledagaintoliquidformandthenalsore-injectedintothegeothermalreservoir.

Inordertooperatecorrectly,anygasesorpollutantinthesteamareremoved.Forveryhightemperatureresources,thewatercanbecontrolledtoflashmorethanoncetorecoverevenmoreenergyfromthe

sameresource(IEA,2012b:14).

4.1.9.3 Binary cycle power station

Abinarycyclepowerplantisusedformoderate-temperatureresources.Thehotwaterfromageothermalsourceisusedtoheatasecondaryworkingfluidinaclosed-loopsystem.Theworkingfluidisvaporisedina

heatexchangerandisthenusedtodriveaturbinegenerator.Acoolingsystemisusedtocondensethe

vaporisedworkingfluidbackintoliquidformtobegintheprocessagain.Thehotwaterfromthe

geothermalresourceisinjectedbackintothereservoirwhereitcanbere-heated.Thehotwaterandtheworkingfluidarekeptseparate,sothatenvironmentalissuesareminimal(IEA,2012b:15).

4.1.10 BioenergiesBioenergy,theenergyfromplantsandplant-derivedmaterials,hasbeenusedinhistorysincepeoplebeganburningwoodtocookfoodandkeepwarm.Woodisstillthelargestbiomassenergyresourcetoday,but

manyothersarecommonlyusedsuchasfoodcrops,residuesfromagriculture,oil-richalgae,andthe

organiccomponentofmunicipalandindustrialwastes.

Theuseofbiomassenergyhasthepotentialtoreducegreenhousegasemissions.Eventhoughbiomassgeneratesaboutthesameamountofcarbondioxideasfossilfuels,thisamountofpollutionis

compensatedbynewplants,whicharegoingtoabsorbthesameamountofcarbondioxide.Thefinalnet

emissionofcarbondioxidewillbezeroaslongasplantscontinuetobereplenishedforbiomassenergypurposes(RenewableEnergyWorld.com,2016).

Ithastobeconsidered,though,thattheevaluationisnotthateasilycomputedas1:1betweenemitted

!"#andnewbornplantabsorbed!"#.Clearingforeststogrowbiomasscouldresultinacarbonpenalty

thattakesdecadestorecover,soenvironmentalagenciessuggesttousebiomasstohelpinthepathtowardsalow-carboneconomy,butnotasafinalsolution.Itisalsopossibletoreducetheenvironmental

impactgrowingbiomassonpreviouslyclearedland,suchasunder-utilisedfarmland,insteadofclearing

forests.

4.1.10.1 Direct biomass combustion

Mostelectricitygeneratedfrombiomassisproducedbydirectcombustionusingconventionalboilers.Theseboilersprimarilyburnwastewoodproductsfromtheagricultureandwood-processingindustries.

Whenburned,thewoodproducessteam,whichspinsaturbine.Thespinningturbinethenactivatesa

generatorthatproduceselectricity.

4.1.10.2 Biomass co-firing

Co-firinginvolvesreplacingaportionofthepetroleum-basedfuelinhigh-efficiencycoal-firedboilerswith

biomass.Co-firingbiomasscansignificantlyreducethe'"#emissionsofcoal-firedpowerplantsandisaleast-costrenewableenergyoptionformanypowerproducers(IEA,2012a:15).



4.1.10.3 Biomass gasification

Gasificationisathermochemicalprocessinwhichbiomassistransformedintoamixtureofseveral

combustiblegases,calledfuelgas.Gasificationisahighlyversatileprocess,duetothefactthatalmostanydrybiomassfeedstockcanbeconvertedtofuelgas.Theadvantageofgasificationisthatusingthesyngasis

thatitcanbecombustedathighertemperaturesthantheoriginalfuel,resultinginamoreefficientprocess.

Theproducedgascanbeusedtogenerateelectricitydirectlyviaenginesorbyusinggasturbines,withthe

possibilitytoguaranteehigherefficiencythanviaasteamcycle,particularlyinsmall-scaleplants(IEA,2012a:15).

4.1.10.4 Anaerobic digestion

Anaerobicdigestionisacommontechnologyusedtoconvertorganicwastetoelectricityorheat.Inanaerobicdigestion,someparticularbacteriadecomposeorganicmatter,intheabsenceofoxygen,

producingmethaneandotherby-productsthatformarenewablenaturalgas(IEA,2012a).



4.1.11 KPIsevaluationforrenewableenergiesInthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweentherenewableenergyproductiontechnologiesintroducedintheprevious

sectionisproposed.Ithelpsgivingaclearandsimpleunderstandingofeachtechnologystrengthandweaknesstowardsalowcarbonfuture.Themainsources

thatinformTable7,below,comefromthesamereferencesquotedineachspecifictechnologysection,withtheadditionofSchlömeretal.(2014),Lazard(2014),Honorio(2003)andEuropeanCommission(2007).

Table7:KPIsevaluationforrenewableenergies

Theme Typeofindicator Hydro Tide Solar Wind Geothermal Bioenergies

GHGEmissionsLife-cycleCO2emissions

(gCO2eq/kWh)24 17 45 12 38 20

Environmentalimpact Mainenvironmentalimpact Landscape Landscape Hazardouswaste Visual-Noise GHGEmissions GHGEmissions

Environmentalimpact Level High High Low-medium Medium Low-Medium Low-Medium


Levelisedenergycost(€/MWh) 86.4 450 210.7

97(onshore)

243.2(offshore)101.7 112.5

Performanceindex Efficiency 95% 85-90% 12-20% 30-45% 25-60% 35-40%

Technologicalregime Infrastructurelifespan 40 40-50 25-30 30 20-30 25

Technologicalregime Maturityoftechnology High Medium Medium Medium High High

Politicalcommitment AvailableGrants&Policysupport



Publicopinion Degreeofacceptanceofthetechnology Medium-High Medium-High High High Medium Medium



Multipledifferentsolutionsexistforelectricityproductionthroughrenewablesources.Themostrelevant

oneishydroelectric,whichisamaturetechnologywithlowGHGemissionandverygoodperformances.Its

efficiencyisveryhigh,itguaranteesgoodperformancesandtheuseofsuchasourceinbigplants,while

providingaverylowrateofGHGemission.Themaindrawbackofsuchatechnologyisthatithasalmostno

moremarginfornewplantsinstallations,sinceplantshavealreadybeenbuiltinallthesuitablenatural

spots.Afterhydroelectric,themostusedandpromisingtypesofrenewablesaresolarandwindenergies,

withthelatterprovidingthelowestGHGemissionlevelamongallthepowergenerationsolutions.

Thefastgrowthoccurredtowindandsolarinthelastdecadeiswellrepresentedinthepercentageof

peopleinfavourtothosetechnologies,whicharethehighestamongallsources,beingsolaratthefirstand

windatthesecondplace.Windandsolargenerationtechnologies,though,stillneedtoimprovetheir

performancesandcosts,inordertobecomereallycompetitivewithtraditionalplantswithouttheneedof

financialsupportanddedicatedpoliciesfromEuropeanCountries.

Geothermalandbioenergiesallowfortheuseinbiggerplantsasheatsources,bothaloneortogetherwith

fossilfuels,inordertoreducetheGHGemissionmaintaininghighperformancesandpowergeneration

levels.Theyarelesssupportedbythecommunitysincetheyemithigherlevelofgreenhousegasesthan

windandsolar.Themaindrawbackofbioenergiesarethedeforestationissueandthefactthat,even

thoughGHGemissionsresultingfromburningbiomasscanbeequilibratedbygrowingnewplants,itcan

takefromdecadestoacenturytodothat.

4.2 DistrictheatingEurostatdatashowthatalmost50%ofthetotalenergyconsumedinEuropeisusedforthegenerationof

heat.Renewableenergyalreadycontributestoheatgenerationwithanimportantshare,withbiomass

accountingfor55%ofallRES.WhentalkinginparticularaboutDistrictHeating(DH),over80%ofheat

suppliedbyDHoriginatesfromrenewableenergysourcesorwasteheatrecoveryfromcombinedheatand

powerplantsofindustrialprocesses.

DHnetworkarepresentthroughallEuropeandcurrentlycoveraround10%ofthetotalannualheat

demand.However,marketpenetrationofDHisunevenlydistributed.WhileDHhasanaveragemarket

shareof10%inEurope,itisparticularlywidespreadinNorth,CentralandEasternEurope,where

temperaturecanreachmuchlowervalueduringwinter,withamarketsharesoftenaround50%andmore

(CrossBorderBioenergy,2012).

InSouthernandWesternregions,whereDistrictHeatingisnotwidespread,eachsinglebuildingprovidesits

ownheating.Thisisgenerallyproducedusingboilers,whicharedimensioneddependingonthespecific

buildingneeds.Thissystemmakesuseofaround75-85%oftheenergycontainedinfossilfuelwhennew

technologiesareinstalled,whichinmanycasedoesnothappen,sinceitisdifficulttoconvincepeopleto

faceabiginitialinvestmentrequiredtoupgradetheboiler.Moreover,boilersusehigh-valueenergysuchas

heatat1.200-1.500°Ctoprovideindoorheatingataround20°C.

Districtheating,ontheotherside,makeuseofasinglecentralorafewbigplantsthatprovideheatto

multiplebuildings.Thisallowforthecontemporaryproductionofheatandpower,resultinginagreattotal

efficiencyimprovement,sinceCHPplantsdonotdisperseprocessheatintheenvironment,butmakedirect



useofitforbuildingheating.Moreover,centralheatproductionensuresbettercontrolontheheatplant,

reducingmaintenancecosts,andallowsfortheuseofenergysourcessuchasMunicipalWaste,thatwould

beotherwiseuseless.

Forthosereasons,topromotetheuseofDistrictHeating,inparticularwithheatsuppliedbyrenewablesor

wasteheatrecovery,isoneofthetargetsoftheEURES-Directivefor2020.

Today,heat-onlytechnologiesandplantsarethemostcommon,whiledistrictcoolingislesscommon,but

isslowlyincreasingitspopularityduringthelastdecades.CombinedHeatandPowerhasalreadygainedthe

largestshareamongdistrictheatingsolutions,eventhoughtheyaretraditionallyfossilfuelledandmany

plantsrunobsoletetechnology.Newsolutionsareslowlybeingintroducedintothemarket,whichmake

prevalentlyuseofbiomasses,i.e.bioCHP,pellets,biofuelsorfuelmixes(CrossBorderBioenergy,2012).

Ingeneral,astrongeruseofrenewablesisforeseenforDH,inparticularofbiomassesandmunicipal

wastes,whichallowssimilarperformancesasfossilfuelsandtheuseinCHPplants,butstronglyreducethe

environmentalimpactandGHGemissions.Othereco-friendlysolutions,suchassolarheating,arealso

gainingmoreandmoreimportanceand,eventhoughthepresenceofaback-upheatgenerationsystemis

stillrequired,theycanprovidegreatadvantages,furtherreducingGHGemissionsandenergydependency

fromfossilfuels.

4.2.1 NaturalgasTheuseoffossilfuelisdominantinheatinggenerationasitisinelectricitygeneration,with70%ofthe

totalEuropeanheatpowergeneratedin2013comingfromnon-renewablesources.Naturalgasisthemost

commonlyused,withmorethan40%ofthetotalshare(Eurostat,2016).

Whenusedforthesolepurposeofheatinggeneration,naturalgasisburnedinaheat-onlyboilerstation,

whichgeneratesthermalenergyintheformofhotwaterforuseindistrictheatingapplications.District

heatingsystemshaveatypicalheatgeneratingcapacitybetween0.5to20MW,withsupplyandreturn

temperaturesof80°C/40°C.Itispossibletoreachhighersupplytemperatures,upto120°Corevenhigher,

inpressurisedsystems(EuropeanCommission,2012a).

Boilersfordistrictheatingareamaturetechnologyandhavebeenusedformorethanthreedecades.

Nowadays,duetotheflexibilityofnaturalgas,mostboilersareusedtomeettheheatingdemandduring

peak-loadperiodsorasaback-upsystemtosupplyenergywhenrequired.Theefficienciesaretypicallyin

therangeof97–105%,basedonnetcalorificvalues(EuropeanCommission,2012b).

Theadvantageofusinggasfiredboilersfordistrictheating,aswehavealreadydiscussedfortheelectricity

production,isthatitcanproduceheateasily,withcompletecontrolontheamountofenergyprovided.For

thisreason,itiscommonlyusedforbackupcapacityindistrictheatingsystemsinwhichthemainpartof

theheatcomesfromothersourcessuchaswastesorbiomass.Themaindisadvantageofthetechnologyis

thatitisbasedonburningafossil-basedenergysource,withtheconsequentemissionofhighlevelof

greenhousegassesintheair.Asaconsequence,EUispromotingtheimplementationofdifferentcleaner

typesoftechnologiesforheatproduction,reducingtheuseofnaturalgasonlyforbackupcapacity.



4.2.2 Combinedheatandpower(CHP)Combinedheatandpowerconsistsinthesimultaneousproductionofusableheatandpower(electricity),inone single,highlyefficientprocess. In conventionalwaysofgeneratingelectricity,avastamountofheatremainsattheendoftheelectricityproductioncycleanditissimplywasted.Thislostheat,oftenwellvisibleasa cloudof steamrising fromcooling towers,usually representsup to two thirdsof theoverallenergyconsumedbycoalandgasfiredpowerplants.

CHP, therefore, is an interesting solution since it efficiently uses theotherwisewasteheat generatedbyelectricalpowerplants,withaconsequentreductionoffinalCO2emissions.Byusingwasteheat,CHPplantscanhighlyimprovetheoverallplantefficiency,reachingratingsevenhigherthan80%.Theimprovementisclearifweconsiderthatelectricalandthermaltotalefficiencyofgaspowerstationrangebetween49%and52%,whileforcoal-firedplantitisevenlower,withanefficiencyofaround38%(Rezaie,&Rosen,2012:4).

Figure10:CHPcomparedwithseparatedpowerandheatgeneration(NorthernUtilities,2015)

CHPisfirstofallanenergyefficiencytechnologyandcanbeappliedtobothrenewableandfossilfuels.The

specifictechnologiesemployed,andthefinalefficienciesachievablewillvaryfromcasetocase,butinall

casesCHPoffersthecapabilitytomakemoreefficientandeffectiveuseofvaluableprimaryenergy

resources.

Whenprovidingalsocooling,togetherwithpowerandheating,aCHPprocessiscalled‘trigeneration’.An

importantexampleoftrigenerationapplicationsinamajorcityistheNewYorkCitysteamsystem.

DirectbenefitsofCHPincludeupto30%energyandcarbondioxidereduction,highoverallefficiencyand

costsavingsaround30%overelectricitysourcedfromthegridandheatgeneratedbyon-siteboilers.Itis

alsoamatureandreliabletechnologywidelyusedworldwide(VV.AA.,2015b:31).

Animportantdrawbackofthetechnology,whichiscommontoalldistrictheatingtechnologies,thatheatis

difficulttotransportforlongdistanceswithouthavingbiglosses.ThismeansthatCHPplantsarean

economicallyvaluablesolutionwhenthereisahighconcentrateddemandforheatclosetotheplant.



4.2.3 SolidbiomassSinceancienttimes,humanbeingshaveusedwoodtoproducefireforheating,cookingandmanyother

purposes.Nowadays,burningwoodisstilltheeasiestandmostimmediatewaytoproduceheating.Among

renewableenergysources,solidbiomasshasthehighestshareonthemarketinderivedheatproduction,

with74.7%in2013(Eurostat,2015).

Thewoodusedinthistechnologycanderivedirectlyfromchippedtrees,fromwoodindustryintheformof

pelletsandfromindustrialwastes.Pelletsareaprocessedformofwood,whichmakethemmore

expensive,buttheircostiscompensatedbythefactthattheyaremuchmorecondensedanduniform,and

thereforemoreefficient.Inaddition,theyprovideseveraladvantagesrelatedtohandling,shippingand

storage,alargecalorificvalue,animprovedpossibilityoftransportingthematerialforlongdistancesand

aneasierimplementationinautomatedlines.

Asalreadyseeninthepreviouschapter,biomassisarenewableenergy,althoughlimitedintheamountof

biomassavailable,andcanbeconsidereda!"#neutralsource.Theenergyproducedfrombiomasshasa

costssimilartoothertraditionalenergysourcessuchasnaturalgas,sometimesevenlower,whichmakesit

notonlyenvironmentallyfriendly,butalsoeconomicallycompetitive.

Atechnologywithpotentialforgrowthinthefutureisbiomassgasification,whichproducesawiderangeof

fuelalternativeslikemethanol,syntheticnaturalgas(SNG)andFischer–Tropschdiesel.

Theadvantageofthetechnologyisthatitcanusewasteproducts,ithelpsreducingtheamountof!"#emittedintheair,eventhoughtherecanbeaminoruseoffossilfuelforrelatedoperationssuchaswood

transportation.Inwell-designedsystems,efficienciesabove110%areachievable.

Thedisadvantagesincludethehighinvestmentcostandtheavailabilityoftheenergysource,whichis

limitedduetotheannualgrowthrateofbiomass.Eventhoughbiomassisconsidereda!"#neutralsource,itmayrequiremanydecadestoequilibratetheamountof!"#introducedintheair.Anotherimportant

issueisthenegativeimpactharvestinghasonforestsandtherelativeecosystem.

4.2.4 WasteUsingwastefordistrictheatingisanefficientwaytoaddressgovernmentpoliciesaimedatreducingfossil

fueluseforspaceheatingandcorrespondingCO2emissions,usingwastescomingprimarilyfromindustry

andhouseholds.Wastefiredplantsareusuallydesignedforincinerationofnon-hazardouswastes,even

thoughincertaincasesitispossiblethatsometypesofhazardouswastesmayalsobeincinerated.

Threecategoriesaredefinedtoclassifythetypesofwaste(EuropeanCommission,2012b):

• Industrialwastes:Wastesofindustrialnon-renewableorigincombusteddirectlyfortheproductionofheatorelectricity.

• Municipalsolidwaste(renewablesources):Wasteproducedbyhouseholds,industry,hospitalsandthe tertiary sector, which contains biodegradable materials that are incinerated at specificinstallations.

• Municipal solidwaste (non-renewable sources): Theyare the sameasmunicipal solidwaste,butcontainsnon-biodegradablematerials.



Thissystemhasvariousadvantages.Wastefiredplantallowtoreachhightemperatures,makingitpossible

tohavecombinedheatandpowergeneration.Producedhotwatercanbeusedforindustrialapplications,

whiledistrictheatingoperationsareperformedwithlowertemperaturewater.Ituseswasteasanenergy

sourceinsteadofusingfossilfuelsorotherenergysourcesand,sincealargepartofthemunicipalsolid

wasteisconsideredasrenewableenergy,itresultsinareductionofCO2emissions.Incinerationofwaste

residuescanalsobeusedforconstructionworks.

Thedisadvantagearethehighinvestmentcostsfortheplantconstructionandoperation,theextensive

treatmentneededtocontrolthepollutedfluegasesandthefactthatthesourceofenergy,evenif

renewable,islimitedtotheamountofcollectedwaste.Moreover,inorderfortheplanttoworkefficiently,

therehastobeasystematiccollectionofwaste,whichneedtobesortedinordertoremovenon-

inflammablewastesuchasglassandmetal.

4.2.5 GeothermalHeatfromundergroundwaterreservoirscanbeutiliseddirectlythroughaheatexchangerandusedina

districtheatingsystem.However,thissolutionishighlydependableonthepresenceofanatural

geothermalsourceintheareaandonthetemperatureitprovideswater.Generally,then,itispreferable

andmoreeconomicallyconvenienttoextractheatfromreservoirslocatedathigherlevels,whichhave

lowertemperatures,andusethatheatinheatpumpsystemstoprovideheating.Thetypicalsystemfor

districtheatingisaclosed-loopsystem,whichtransferstheheattothedistrictheatingnetworkthrough

heatexchangersand/orheatpumps,andthenreinjectionthecooledwatertothereservoirtobere-heated

(GEODH,2016).

Theadvantageofthesystemisitsgoodperformanceandthatitusesanaturalenergysourcewithnoneed

forcombustion,withconsequentreducedCO2emissions.Thedisadvantagesaretheinvestmentcosts,the

possibilityofpollutantspresenceinthegeothermalwaterandthelimitstotheavailabilityoftheenergy

source.Thetechniqueis,infact,onlyapplicableatthespecificgeographiclocationswheregeothermal

sourcesarepresent,sinceheattransportationismuchlessefficientthanelectricityone(European

Commission,2012b:20).

4.2.6 SolardistrictheatingThistypeoftechnologyisrelatedtolargeinstallations,whichareusedforproducingheatfordistrict

heatingsystems.Solarheatingsystemsusesolarcollectorsandaliquidhandlingunittotransferheattothe

loadgenerallybyusingstorage.Aswehavealreadydiscussedforsolarelectricity,sincesolarpowerisan

intermittentsource,thissystemrequiresadditionalheatgenerationcapacityinordertomeetallthe

heatingneedsofthecommunityduringperiodsofinsufficientsunshineorduringwintertime.This

additionalheatcanbeobtainedbyotherbackupenergysource,whichcanbebasedonbiofuels,waste,or

fossilfuelsasnaturalgas,oilorcoal.Otherpossibilityisthecogenerationwithheatandpower(CHP)orthe

useofheatpumps(EuropeanSolarThermalIndustryFederation,2016).

Thesolarcollectorstypicallyusedarehighlyefficientflatplatecollectors.Othersystemssuchasthe

concentratingsystemscangeneratehighertemperaturesandaremostusedinareaswithahighlevelof

directsolarirradianceforpowergenerationorhigh-temperatureapplications.Theefficiencyishigherifthe



temperaturelevelofthedistrictheatingsystemisrelativelylow.Duetotheclimaticvariationsduringthe

year,itislesscosteffectivetohave100%coverageoftheheatingdemandthantohavepartloadcoverage.

Thesesystemsareapplicablewherevertherearedistrictheatingnetworks,inorderforthesolarheating

systemtoconnecttoit.Usuallysuchnetworksexistincoldclimates,wherethereisasubstantialdemand

forheatduringautumnandwinter.Althoughitmaybeconsideredthatusingsolarthermalenergyinsuch

climateswouldbeneitherfeasiblenorcompetitive,therealityprovestheoppositetobetrue.Themain

disadvantagesareitshighinvestmentcostandtheneedforalargeareaforthepanelinstallation,since

highquantityofheatareneededfordistrictpurposes(EuropeanCommission,2012b:12).

4.2.7 HeatpumpfordistrictheatingHeatpumpsusuallydrawheatfromtheambientandconverttheheattoahighertemperaturethrougha

closed-loopprocess.Wearegoingtodiscussheatpumpsinmoredetailswhentalkingaboutbuilding

heatingintheEndUserchapter.Thisbecauseheatpumpsareatechnologybettersuitedforsmaller

installationsthandistrictheatingduetothefactthatitishardertoregulateandcontrol.Evenso,this

technologystillfindssomeapplicationindistrictheatingandseveraltypesofinstallationsareavailable:

• Largeelectricalheatpumpsfordistrictheatingsystems:theyabsorbheatatambienttemperatureor,ifavailable,fromwasteprocessheat.Supplytemperatureisaround80°C,withatypicalcapacityof1to10MWofgenerationheat.Dependingontheworkingfluid,theCOP(CoefficientofPerformances)mayvary,reachingvaluesupto4.5.

• Largeabsorptionheatpumps–biomassheatsource:Theyusuallyworkinconnectionwithmunicipalsolid waste and biomass plants, but natural gas might also be used. They provide district heatingtemperaturearound80°C,withatypicalcapacityof2to15MWofheatgeneration.TheCOPisusually1.7.

• Largeabsorptionheatpumps–geothermalheatsource:Geothermalwaterisusedtoheatwaterforadistrictheatingsystemaround80°C,withatypicalcapacityof2to15MWofheatgeneration.TheCOPisaround1.7.

Theadvantageofaheatpumpsystemisthatitusesfreeambientenergyorwasteheatandtransformsitto

ahighertemperaturesuitableforheatingpurposes.Thedisadvantageistheenergyneededforthe

transformation(electricityorhigh-temperatureheat),whichmaycomefrompollutingsources,andthecost

ofthenecessaryequipment.Theadvantageoftheelectricallydrivenheatpumpscomparedtoabsorption

heatpumpsisahigherefficiency.However,whentheheatneededtoruntheabsorptionheatpumpsis

availablealowercost,e.g.industrialwasteheat,absorptionheatpumpsmaybeafavourableoption

(EuropeanCommission,2012b:14-17).

4.2.8 KPIsevaluationfordistrictheatingtechnologiesInthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweendistrictheating

productiontechnologiesintroducedintheprevioussectionisproposed.Asalreadydonefortheelectricity

productiontechnologies,ahighlevelcomparisonisperformedhere,dividingthedependingonthesource.

Theproposedtablehelpsunderstandingeachtechnologygroupprosandcons.Themainsourcesthat

informTable8,below,comefromthesamereferencesquotedineachspecifictechnologysection,withthe

additionofPöyryEnergyConsulting(2009),VV.AA.(2015b).



Table8:KPIsevaluationfordistrictheatingtechnologies

Theme Typeofindicator Naturalgas CHP Solidbiomass Waste Geothermal Solarthermal Heatpump

GHGEmissionsLife-cycleCO2emissions

(gCO2eq/kWh)469

30%reductioncomparedtoonlyelectric

plant

20

40(MSW)200(Non

biodegradablewastes)

45 22Indirectfromelectricity

consumption

Environmentalimpact Mainenv.impact GHG

Emissions

Noadditionw.r.t.electric

plantGHGEmissions GHGEmissions Releaseof

pollutant - -

Environmentalimpact Level Medium-High - Low-Medium Medium Low-Medium - -


Investmentcost(€/MWh) 130-155 115

155-185250(Anaerobic

digestion)260 65-200 100-130 110-130

Performanceindex Thermalefficiency 97-105%70-90%(Totalelectrical+thermal)

10-30%(traditional)90%(pellet)

90% 15-30% 25-30%

COP=1.7(Absorption)COP=4.5(Electrical)

Technologicalregime

Infrastructurelifespan(years) 40 40 25 15 20-30 25 15

Technologicalregime

Maturityoftechnology High High High High High Medium-High High

Politicalcommitment


EnergyRoadmap2050|2030climate&energyframework(Eachmemberstateisfreetotakeindividualdecisionsonthemeasurestoreachthesetobjectives)


acceptance(%citizensinfavour)

Medium Medium-High Medium Medium Medium High Medium-High



Naturalgasisthemostusedenergysourcefordistrictheating.Evenif,asalreadysaidfortheelectricity

generation,naturalgasprovideslowerpollutantemissionsthancoalandoil,therearestillmoreclean

solutionstoapply.Combinedheatandpowerplantisthemosteffectivesolution,whenthereistheneed

fordistrictheatingclosetoapowerplant.CHPhighlyimprovespowerplantstotalefficiency,reducingthe

GHGemissionsby30%.Itisalsoasimpleandmaturetechnology,whichdoesnotaffecttheplantlifespan.

Themostusedrenewablesourceforheatingisbiomass,whichcanachieveveryhighefficiencythankto

modernsolutionssuchastheconversionofwoodintohighlycompressedanddrypellets.Themain

drawbackremainthetimeneededtoequilibratetheGHGemittedwithanew-grownplant.

Solarthermalprovidesagoodsolutionasacomplementtoanalreadyexistingdistrictheatinggrid.Ithas

evenlowerlife-cycleGHGemissionsthanphotovoltaicandarelativelowcost.Thetechnologyisnot

matureyettocompetewithfossilfuelsandprovideatotalheatbasefordistrictheating.

Whengeothermalsourcesarenaturallypresent,thistypeofsolutionprovestobeaveryefficientchoice,

characterisedbyparticularlylowcost.Moreover,geothermalismoresuitedtoheatpurposesthanpower

generationones,sincelowertemperaturesareneededindistrictheatingthaninpowerplantstogenerate

thesteamthatmovestheturbines.

5 Energytransportationanddistribution

Thesecondstepoftheenergysupplychainisconstitutedbytransportation.Itaimstotakeanenergy

sourcefromitsextractionorproductionsite,andmoveitthroughthebignationalortransnational

infrastructurestocentraliseddistributionfacilities.

Thedistributionstepcoversamorecapillarynetworkofthesupplyinfrastructure,takingtheenergysource

totheendusers(residentialbuildings,industries,services,etc.).

Itisveryimportanttotechnicallyevaluatethesetwophasesoftheenergysupplychain,becausethe

transportationanddistributionaspectscanhavehugeimpactsonseveralcrucialpointsofthisindustrial

field.Theycanaffectthefinalenergycosttotheenduserandlandscapeimpactscanbecausedbythe

transportationanddistributioninfrastructures,withsubsequentsocialchangesthatarenoteconomically

computable(residentialvaluedecreasing,lifequalityworsening,etc.).Moreover,environmentalimpacts

suchascarbonemissionsandotherpollutantsareworthevaluating,togetherwiththeriskofserious

environmentalaccidentsassociatedwiththetransportationanddistributionofenergysources,likeinthe

caseofoiltankervesselsdamages.

Transportationanddistributiontechnologiescanactontwodifferentsegmentsoftheenergychain:

• primaryenergysourceslikecoal,oil,gas(i.e.,thosewhichhavenotbeentransformedintoany

otherenergyformyet)arecarriedfromaplacetoanotherandthendistributedtotheir

transformationsitesandplants(i.e.,thermalpowerplants,residentialbuildingsheatingplants,

publicservicesbuildings,etc.)

• alreadytransformedenergy(e.g.,electrichighvoltage)istransportedanddistributedtoendusers(houses,industries,etc.).



Inthissection,anoverviewofthemainenergytransportationanddistributiontechnologiesispresented.

Then,theKeyPerformanceIndicatorsdefinedinChapter3areusedinordertoquantitativelyand

qualitativelyevaluateeachlistedtechnology,withacomparativeanalysisoftheenergytransportationand

distributionscenario.

5.1 ElectricityElectricitypoweriswidelyusedineverysocial,workingandproductionaspectofhumanlife.Itisproduced

intheformofapotentialdifferentialbetweentwoormoreconductors,andunderthesameformitis

transportedanddistributedfromthepowerplanttothegridnodesandtheperipheralendusers’sites.

Thepresentparagraphdifferentiatessometechnologywhichisusedinthisfield.

5.1.1 3-phaseOverheadTransmissionThe3-phaseoverheadtransmissionisthemostusedtechnologytofacetheproblemoflongdistancestobe

coveredwhenacertainamountofelectricalenergyhastobetransportedtothedistributionssites.This

technologyisadoptedwithhighvoltagetobepassedthroughtheconductors,duetothelongdistances

whichcouldcausetoohighleakagesincaseoflowvoltagetransmission(infact,longconductorsmeanhigh

resistancesandsubsequentlyhighvoltagedrops).

When3-phaseoverheadtransmissionisadopted,highvoltageisconductedthroughamaterialwhichoften

isanaluminiumalloy,whichallowslowweight(importantaspectforoverheadinfrastructureinstallation)

andlowcostsifcomparedtootherconductorslikecopper.Theconductinglineiscomposedbymetal

strandswhicharemechanicallyreinforcedbyintroductionofsteelstrands.Theresistanceiskeptlowby

usingveryhighconductorsections,upto750mm2.

Themainissueofsuchatechnologyisthelandscapeimpact,togetherwiththeenvironmentpollutiondue

toitsinstallationphase(componentstransportation,industrialmachineryutilisationnforassemblyand

mounting).Electricfieldcreatedbythehighdifferentialpotentialisanotherimpactingaspectofthis

technology.Moreover,badweatherconditionscanaffecttheconductionperformance(Betzetal.,2009).

Thiskindofinfrastructureisadoptedforboththeelectricitytransportationanddistributionphases.

5.1.2 BundleConductorsDuetotheso-calledskineffect,electriccurrentflowsmoreclosetotheconductorsurfaceratherthan

internallyinthematerialbulk.Thisphenomenonisexploitedbybundledconductorsinfrastructure,which

areusedinordertooptimisetheperformanceofhighvoltageelectricitytransportation(Graingeretal,

1994).

Thebundledconductorsaremultipleparallelcablesoftenusedinsteadofsinglecablesforoverhead

transmission.Thistechnologyaimstoreduceatminimumtheenergylossesduetocoronadischargeeffect,

bywhichthehighpotentialvoltagecablecausesthesurroundingairionisationn,aswellasmaximisingthe

surfaceandcapacityoftheconductors,thuscreatinganelectricarc,dischargingapartofelectricenergyto

theground(Freimark,2007).



5.1.3 3-phaseUndergroundTransmissionThissolutionisadoptedtofacewithelectricitytransportationanddistributionproblems.Itistechnically

thesameasthealreadyseenoverheadtransmission,butitisinstalledafterexcavationsunderground.

Differentlyfromtheoverheadtransmission,thiskindofhighvoltagetransportationismorestable(i.e.,itis

notaffectedbyweatherconditions),anditdoesnotneedpylons.Asaconsequence,itcanbeinstalledin

particularsituationssuchastocrossshortseaareas,makingitamoreflexiblesolutionforenergy

transportationanddistribution.Moreover,thehugelandscapeimpactduetooverheadinstallationsis

avoidedbyundergroundlines.

Ontheotherhand,installationactivitiessuchasexcavationsandcablescreatehighercoststhan3-phase

overheadtransmissionslines.

5.1.4 VoltageTransformersThetransportanddistributiongridischaracterisedbyseveraltechnicalparametersthatneedtobetaken

intoaccountinordertohavegoodperformances.Then,voltagetransformersstationsareneededtoload

thegridwiththerightvoltagerange.

Infact,theelectricpowerisproducedatthepowerplantsbetween2.3kVand30kV,anditneedstobe

increasedbecausethelongdistancesofthetransportationgridcauselossesandvoltagedrops.So,the

transformer’stechnologyisusedtotakethevoltageupto115kV/765kVACbeforeloadingthegridwith

it.

5.1.5 SubtransmissionAftercrossingthetransportationlevelofthepowergrid,electricityfeedsdistributionramificationsinorder

tograduallyreachthemostperipheralareasandrespectiveendusers.

Subtransmissionisthepartofpowertransmissionworkingatmediumandlowvoltages(VV.AA.,2011b).

Substationsareconnectedtohighvoltagetransmissionline,andtransformersdecreasethevoltagefora

shorterdistancedistribution.Smallersubstationsattownlevelarethenconnectedtothismediumvoltage

lines,wherethevoltageissteppeddownagain(Finketal.,2007).

Then,bymeansofvoltagetransformerstation’stechnology,acompletetransportationanddistribution

gridismanaged.

5.1.6 TransmissionGridExitFinally,whentheelectricpowerhastoexitthedistributiongridinordertofeedthesingleendusers

(buildings,industries,transportservices,etc.),thevoltageisoncemoretakendowntoalevelwhichis

nationallyregulatedandvariescountrybycountry(e.g.,220V-50HzinItaly).

5.1.7 KPIsevaluationforelectricitytransmissiontechnologiesInthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthedifferent

analysedtechnologiesforelectricitytransportationanddistributionisproposed.TheproposedKPIsand

theirvaluescangivesomeclarificationsabouteachtechnologystrengthandweaknesstowardsalow

carbonfuture.



ThemainsourcesthatinformTable9,below,comefromthesamereferencesquotedineachspecific

technologysection,withtheadditionofEuropeanCommission(2015)andEASAC(2009).

Table9:KPIsevaluationforelectricityT&D

Theme Typeofindicator3-phaseOverhead

Transmission

BundleConductors

3-phaseUndergroundTransmission

Subtransmission

Environmentalimpact

Majorimpacttypegenerated

High

landscape

(visual)

impact,high

electromagnet

icinduced

field

High

landscape

(visual)

impact,high

electromagnet

icinduced

field(for

overhead

application)

CO2

emissions,

yardlogistic

impacts,

noiseimpact.

CO2emissions,

yardlogistic

impacts,noise

impact

(underground

transmissionin

urbanareas)


Costoftransported

energy

1.5M€/kmfor

installation

More

expensiveto

installthan

normal

overheadline

40M€/kmfor

installation

50k€-1

M€/kmfor

installation

Performanceindex

EfficiencyEnergy

carried/(energycarried+energyconsumed+

losses)

0.94 0,96 0,96 0.94-0.96

Technologicalregime

InfrastructureLifespan(years) 80 80/40 40 40

Technologicalregime

Maturityoftechnology High Medium High High

Technologyflexibility

Possibilitytoreachdifferent

locationsMedium Medium High High

Politicalcommitment

AvailableGrants&PolicySupport IntegratedEuropeangriddevelopmentsupportedbyEU



Medium,

stable High,stable High,stable High,stable



Themaindifferencesbetweentheperformanceoftheelectricitytransportanddistributiontechnologies

regardtheenvironmentalimpactandcostaspects.

Inparticular,the3-phaseoverheadtransmissiontakesthebiggestlandscapeimpact,butthisisnotthe

mostpollutingtechnology:duringtheinstallationphaseofanundergroundtransmissionline,indeed,the

highCO2emissionsduetotheexcavationmachineriesrepresentthemainenvironmentalimpact.

Moreover,theyardsetupduringthisphasecancauselogisticissuessuchasthetransportationand

disposalofexcavatedmaterial.

Theyardlogistics,furthermore,causethemuchhighercostsofanundergroundlineinstallationif

comparedtoanyotherelectricitytransmissionsolution,asshowninTable8.Thecorrosionactionofthe

undergroundenvironmentmakesithaveashorterlifespanthanoverheadlines.

Ontheotherhand,themainadvantageof3-phaseundergroundtransmissionisthetechnologyflexibility,

beingabletoreachzoneswhereanoverheadinstallationwouldbeimpossibleorverydifficulttorealise

(e.g.,transmissionthroughasea).

Fromapolicypointofview,theEUhasdesignated€70milliontofinance9innovativeprojectstoimprove

electricitytransmissiongrid,inordertocreateanintegratednetworkatcommunitylevel,tomeetthe

increasingenergyexchangeneeds.

5.2 OilOilisaprimaryenergysourcelargelyadoptedfortransformationintoelectricenergyinoilpowerplants,

refinementintofuelforvehiclemovementanddirectburninginheatingsystems.

Thisenergysourceisextractedfromsoilandunderwaterdepositsinlimitedareas,andithastobe

transportedthroughlongdistancesinordertobeavailableforendusers(i.e.,refineries,industries,heatingsystems).

Inthissection,themostexploitedtechnologiesforoiltransportationanddistributionarelisted.

5.2.1 PipelinesUsually,thefirstsegmentofcrudeoiltransportationstartingfromtheextractionsiteisperformedbymean

of pipelines, which are constituted by tubes with a pressure differential that makes the fluid flow in a

determineddirection.

Thissolutioniswidelyadoptedintheoiltransportationand,onaton-milebasis,ithasbeenestimatedthat

71%ofcrudeoilistransportedbythismethod.

Themainadvantagesofpipelinesarebotheconomicandenvironmental: infact,thistechnologyrequires

significantlylessenergytomoveacertainoilamountalongadetermineddistance,ifcomparedtoothertools

liketrucksorvessels(Trench,2001).Furthermore,ithasamuchlowercarbonfootprintontheenvironment.

Fromareliabilitypointofview,pipelineshavegoodperformancestoo,duetothelowriskofenvironmental

damagesandaccidents.

Themaindisadvantageofthistechnologyisitslowflexibility,beingafixinfrastructureabletomovecrude

oilforlongdistancesbutonlytodeterminedareasreachedbytheline.Anotherdrawbackisrepresentedby



thehigh installationcosts (Karangwa,2008),with theneedingofbigstarting investments tobuildsucha

facility.

5.2.2 PumpStationsTheoilflowthroughthepipelinesisassuredbypumpsystemsoperatingbothbeforeenteringthepipeline,

afterhaving collectedcrudeoil from fieldgathering systems,andalong thepipeline itself.Here,booster

pumpsarelocatedinordertomaintaintherightpressure(i.e.,upto150atm)andkeeptheoilflowing.

5.2.3 TankerShipsTheproblemoftransportingcrudeoilthroughtheoceans,fromacontinenttoanother,canonlybefacedby

tankervessels.Thismethodallowstosimultaneouslycarrymanybarrelsofoil,makingthetransportation

priceperbarrelverylowifcomparedtolandtransportvehicles.

Analternativetothebig,propelledtankershipsarebarges,whicharesmalleranddonothaveanypropulsion

system;theyareusedtomovecrudeoilincalmwatersandforshortdistances,andarepushedortowedby

tugs(PetroStrategies,2015).

Obviously,themaindrawbackofthistechnologyisrepresentedbytheflexibility,beingabletocarryoilonly

through the sea and rivers. It has to be used in combination with another technology when the oil is

downloadedattheharbour.

Marineoiltransportationwithvesselshasalsothehighestimpactanddamagepotentialincaseofaccident,

withmanybarrelsofoilwhichcanpolluteoceansifatankerhasleakagesorsinks.

5.2.4 TankTrucksAfterlong-distancetransportphases,primaryenergysourcessuchascrudeoilanditsderivativefuelsare

distributedtotheendusersbytanktrucks,whichrepresentthemostflexibletechnologytomovethem.In

fact,tanktruckscanpotentiallyreacheveryplacewherethereisaroad,thusmakingitparticularlysuitable

forretaildistributionpurposes.

Themaindisadvantagesofusingthiskindofvehiclearethelowstoragecapacity(only80or100barrelsof

oilforeachtruck)andthehighcostsandcarbonfootprintduetothetrucksfuelconsumption(PPIAF

website,2016).

5.2.5 RailsSimilartothetanktrucksdistributionmethod,crudeoilanditsderivativescanbemovedbyusingtrains:

thistechnologyisgenerallyhaslessofanimpactcomparedtothepreviousone,andtakestheadvantageof

therailway,analreadyexistinginfrastructurebuiltformoregeneralpurposes.Thismakesrailtechnology

moreflexiblethanthepipelines,eveniftanktruckssystemisthemostflexibledistributionmethodatall.

Asingletrain(about8,000barrels)cancarryquitealargeamountofcrudeoil,whichkeepsdistribution

costslow(PPIAF,website,2016).

5.2.6 KPIsevaluationforoiltransmissiontechnologiesInthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthedifferent

analysedtechnologiesforcrudeoiltransportationanddistributionisproposed.TheseKPIscanhelpinthe

characterisationnofeachtechnologyundertechnical,economicalandenvironmentalaspects.

ThemainsourcesusedtofillinTable10comefromthesamereferencesquotedineachspecifictechnology

section,withtheadditionofDirectorategeneralforInternalPolicies(2009)andKiefner&Rosenfeld(2012).



Table10:KPIsevaluationforoilT&D

Theme Type Pipelines+pumpstations TankerShips TankTrucks Rails

EnvironmentalimpactMajorimpact

typegenerated

Yardlogistic

andnoise

impactduring

installation,

landscape

impact

CO2

emissions,

environment

aldisaster

risks

CO2

emissionsLogistic

issues


Costoftransported

energy€/(barrel*km)

0,0020,00005

considering2

Mbarrelship0,00325 0,008

Efficiencyintransportandconsumption

Energycarried/(energycarried+energy

consumed+losses)

-

0,98

(considering

2Mbarrel

shipand

10000km

shipping)

0,96

(considering

2000km

driving)

0,99

(considering

2000km

transportatio

n)

InfrastructureLifespan years/infrastructure 80 30 15 20


yearssinceemergence 150 150 110 150

TechnologyflexibilityPossibilitytoreachdifferent

locationsLow Low High Medium

PoliticalcommitmentAvailableGrants&

PolicySupport - - -

Publicopinion

Degreeofacceptanceof

thetechnology

Medium-

decreasingLow Medium Medium

Asshowninthetableabove,allthepresentedoiltransportanddistributiontechnologieshaveastrong

historicalmaturity,sinceallofthemhadtobestudiedanddevelopedintheperiodofoilextractionand

consumptionincreasing(1860s).

Oilpipelines,ifcomparedtoothersolutions,haveahigherimpactintermsoflandscapedamagesandyard

logistics,andithasaverylow,practicallynull,flexibility:itcantakeoilonlywherededicatedinfrastructure



hasbeenbuilt.Ontheotherhand,oncebuilt,thistransportmethodhasamuchhigherlifespanthanother

ones(ifthepipelineiswellmaintained,otherwisetheriskofaccidentgreatlyincreases).

Everyconveyance-basedmethodischaracterisedbyahighefficiency(railwaydistributionbeingthe

highest),duetothelargenumberofbarrelsthatcanbecarried.

Referringtothetransportationanddistributioncosts,vesselshippingisthecheapestwaytomovetheoil

massunitalongacertaindistance(becausetheshippingcostisdistributedoverahugeamountofoil,e.g.,2millionbarrels).Pipelinesalsohavequitealowcosttoointermsof€/(barrel*km);tanktruckandrailhavehighercostsduetothelimitedcapacityoftheseconveyances.

5.3 GasAnotherprimaryenergysourceisnaturalgas,whichisextractedfromthesoilandhastobedeliveredto

distributionfacilitiesandendusers.

Itismainlyusedintheheatingsystemsforresidentialbuildingsandindustrialsites,furtherthaninelectric

powerplantstoproduceelectricity.

Inthepresentsection,differentadoptedtechnologiesareshowninordertoevaluatetheirpeculiaritiesand

theirimpacts.

5.3.1 Pipelines-GatheringSystemOncethenaturalgashasbeenextractedfromthewellhead,inordertotransportittoprocessingfacilities,

smalldiameter(from6to48inches)carbonsteelpipelinesareused.Thisrepresentsthesafestmethodof

gastransportation,andinordertoreducetheriskofleakageswhenthepipeisputintotheground,itis

coveredwithaspecialisedcoating,whosepurposeistoprotectthepipefromthegroundmoisture,which

couldcausecorrosionandrusting.

Asmentionedforoilpipelines,thiskindofinfrastructurehasthedisadvantagesofalowflexibilityandhigh

investmentcostforitsinstallation(Karangwa,2008).

5.3.2 Pipelines-InterstateSystemInterstatepipelinesareconceptuallythesametechnologyasgatheringpipelines,butinthiscasethe

infrastructuregridsarelargerandtheyareaimedattransportingnaturalgasthroughcountriesandtheir

boundaries,inordertoallowrawgascommerce.

Interstatepipelinesincludeagreatnumberofvalvesalongtheirlength,workinglikegateways;theyare

usuallyopenandallownaturalgastoflowfreely,ortheycanbeusedtostopgasflowalongacertain

sectionofpipe.

5.3.3 CompressorStationsNaturalgasinthepipelinesneedstherightpressurelevelinordertocorrectlyflowtowardsthegathering

systems,processingunits,distributionpointsandendusers.Inordertoachievethispressure,compressor

stationsaresetupalongthelines.Thesefacilitiesareequippedwithgastreatmentunits,aircoolers,shut-

offcontrolvalves,lubricationsystems,fuelandimpulsegasmake-upunits,andpowersupply.

Compressorstechnologyisadoptedforbothgastransportationanddistributionphases.

5.3.4 LNGTankersFurtherthanwhatalreadymentionedforcrudeoil,shipscanbeusedtotransportnaturalgas.Toexploit

thistechnology,thegasisshrunkto1/600ofitsoriginalvolume,inordertotransportareasonablemassof

gasononeship.Duringtheshrinkingoperation,thegasisliquefiedandbecomesLiquefiedNaturalGas



(LNG),whichcanbestoredinpressurisedandrefrigerated(thetemperatureofthegasistakendownto-

162°Ctoliquefyit)tanks,andthentransportedonvessels(USDept.ofEnergy,2005).

Aspreviouslymentioned,themaindrawbackofshiptransportationisthelowflexibilityandtheneedof

otherlandtransportation/distributiontechnologiesincombinationwithit.

Atthedeliverypoint,theLNGisre-gasifiedintonaturalgasandaddedintoagaspipelinesystem.

5.3.5 GasHydrateTransportationApossiblefuturealternativetothepreviouslymentionednaturalgastransportationmethodsisbeing

studiedinthisperiod:naturalgashydratesareindeedconsideredasapossibilityforthestorageand

subsequentlyforthetransportationofnaturalgas.

Severaltechnologiesareunderresearchinordertofindthebestwaytoproduce,shipandregasifysuch

materialscontainingnaturalgasmolecules.

Atthemoment,naturalgashydratesislesscost-effectivethantheLNGtransportationmethod,duetothe

lowerdensityofnaturalgaswhichcanbestoredinthem.However,thissolutioncouldbeeconomically

viableforsmallcapacitypeak-shavingplantsandnaturalgasstorageduetothecostsassociatedwith

naturalgashydratesynthesis,whicharelowerthantheLNGproductioncosts(HydraTech,2016).

5.3.6 KPIsevaluationforgastransmissiontechnologiesInTable11themainKPIsforatechnical,economicandenvironmentalcomparisonbetweenthedifferent

analysedtechnologiesfornaturalgastransportationanddistributionisproposed.Thesefigurescanhelp

assessingthevarioustransportationmodes.

Themainsourcesusedtofillinthetablecomefromthesamereferencesquotedineachspecific

technologysection,withtheadditionofKiefner&Rosenfeld(2012),INSEE(n.d.),Directorate-Generalfor

InternalPolicies(2009),NaturalGas,(2016).

Table11:KPIsevaluationfornaturalgasT&D

Themes Type Pipelines LNGonships GasHydrateonships

Environmentalimpact Majorimpacttypegenerated

Yardlogistic

andnoise

impactduring

installation,

landscape

impact

CO2emissions CO2emissions


Costoftransported

energy€/(m3*km)

0,00003

€/(m3*km) 115*10

-9€/(m3/km)

WorsethanLNG,

because1m3of

gashydrate

contains150m3

naturalgasPerformanceindex

Efficiency(Energy

carried/(energycarried+energyconsumed+losses))

0,95 0,998(considering

10000kmshipping)

Technologicalregime InfrastructureLifespan(years) 80 30 30



Themes Type Pipelines LNGonships GasHydrateonships

Technologicalregime Maturityoftechnology High High Low


locationsLow Low Low

Politicalcommitment AvailableGrants&PolicySupport

BalticEnergyMarket

Interconnection

Plan,with

constructionofa

LNGterminal

servingBaltic

countriesand

Finland

HYDRATECHEU

project



Medium,stable Medium,stable -

InTable11thetraditionalpipelinetransporttechnologyiscomparedtotechniquesofcarryingnaturalgas

afteraphysicalstatuschange.Thesetechniques(LNGandhydrates)areconsideredwithmarinevessel

transportation,inordertohaveacomparisonbetweentheirgeneralcostsandefficiencies.Thesame

considerationsarestillvalidforthelanddistributionmethods(trucksandtrains),sincecostsandenergy

consumptionarestrictlyrelatedtotheadoptedtechnology.

LiquefiedNaturalGasisthecheapestlongdistancetransporttechniqueofall,becauseoftheveryhigh

volumeratiobetweennaturalgasandLNGtransported(600/1).Thisextremeshrinkageallowsasingle

vesseltocarryahugeamountofnaturalgasthatcanberegasified(upto3x109m3),withasubsequent

lowpriceandlowenergyconsumptionforeachcubicmetreofnaturalgas.Thisenergydensityisbetterin

thecaseofnaturalgashydratesonavessel,aseachcubicmeterofmaterialcontainsupto150m3of

naturalgas.

Pipelinesinfrastructuresarecharacterisedbyhighertransportationcosts,buttheyhaveamorestable

technologicalmaturityandalongerlifespan.Moreover,theyhavealowerCO2footprintascomparedto

theothertwopresentedtechnologies(theirmainimpacts,indeed,arerepresentedbylandscapeand

logisticissues).TheEUCommissionispushingR&Dactivitiesoninnovativegastransportanddistribution

methodswithprogramslikeBEMIPandHYDRATECHproject.



5.4 CoalThissectionisdedicatedtocoal,anotherprimaryenergysourcewidelyusedinelectricityproduction.

Sincethedistancebetweenthesupplypointandthedemandpointisoftenlong,coaltransportation

technologiesfacecostswhichareoftenhigherthanminingcoststhemselves,andenvironmentalimpacts

includingairpollution,solidwastes,noiselevels,safetyandtraffichazards.Directenvironmentalimpacts

canoccuratthemine,wherethecoalisbeingtransferred,transportedorloaded.Indirectimpactsfrom

coaltransportationlargelyresultfromthecombustionoffuelforthetransportationitself.

Severaltechnologiesareusedforitstransportationfromtheminingsitestothedistributionfacilitiesand

powerplants,whereitisburnedtoconvertthecombustionheatintoelectricpower.

5.4.1 RailroadTrainsBothfortransportationanddistributionpurposes,railwayinfrastructuresareusedwithinthecoalsupply

chain.Coalcanbemovedfromtheextractionsitetoadistributionplace,ortotheenduser(i.e.,powerplant)byageneralfreighttrainoradedicatedtrain.Themaindifferencesbetweenthesetwosolutionslie

intheflexibilityandinthetransportationcosts:adedicatedcoaltrainonlyhandlescoalfromasingleorigin

toasingledestinationsothatitismuchfasterandcheaperthanthegeneraltrain,whichisamoreflexible

waytousethiskindoftechnology.

Generalpurposefreighttrainstypicallyhandlefrom1,500to6,000nettons,withanaverageofabout

3,000nettons.Incontrast,dedicatedtrainscancarry7,500to12,500nettonspertrip(McKetta,n.d.).

5.4.2 CoalPipelinesAswellasfortransportingoilandgas,pipelinetechnologycanbeusedtotransportanddistributecoaltoo.

Inparticular,twodifferentmethodsaresuitableformovingcoalfromwhereitisminedtowhereitis

consumed:coalslurryandcoallog.

Inthecaseofcoalslurrypipelinetransportation,aslurryofmixedwaterandpulverisedcoalispumpedinto

theline,havingamixingratioof1to1byweight(OTA1978).Afterthetransportationthroughlong

distances,theslurryneedstobewelldried,otherwiseitselectricitygenerationpotentialwillbelower.

Coallogpipelinesusecoalthathasbeencompressedintologswithadiameter5to10%smallerthanthe

pipelinediameter,andalengthabouttwicethepipelinediameter.Alsointhiscasewaterisusedinorder

tomovethecoal,andthecoal/waterratiois3or4to1(Marrero).Duetothetightcoalcompressioninto

logs,itdoesnotabsorbmuchwater,sothistechnologydoesnotneedthesamedryingprocedureascoal

slurry.

Coalpipelinescanbeusedwhereinfrastructuresuchasrailwaysormarinetransportationarenotpresent,

withouthavingagreatflexibilityfromapointofviewofreachableplaces.

5.4.3 BargesTransportMarinecoaltransportationisasolutiontomovecoalworldwide,fromacontinenttoanotherone.Inthis

case,coalisusuallymovedinopenbargeshavingcapacityrangingfrom1,000to3,000nettons,withan

averageof1,500nettons(McKetta,n.d.).10–14bargesarenormallylocatedinseries,sothemain

advantageofthiskindoftransportationisthelargeamountofcoalthatcanbemovedwithasingle

shippingsinceatypicalshipmentcancontainupto30,000nettonsofcoal(McKetta,n.d.).

Terminalfacilitiesforcoaltransportareinvolvedwitheithertheloadingorunloadingofbarges,with

loadingcapacitiesforcoalrangingfrom1,000to4,000tonsperhour.Unloadingofcoalcantakeplaceby

bucket,orrevolvingscoop,withsubsequentconveyormovementtostoragesilos,loadingfacilities,orend-

usepoints.



5.4.4 HighwayTruckMovementThemostversatilemethodofcoaltransportationanddistributionisrepresentedbyroads,onwhich

vehiclesliketruck,havingcapacitiesbetween15and30tons,cancarrythisprimaryenergysourcealmost

allovertheworld.Ontheotherhand,thelogisticsolutionisaffectedbytherelativelylowcapacityofa

singletruck,whencomparedtoothertechnologieslikebargetransportationorcoalpipelines(McKetta,

n.d).

Otherissueslikethehighcarbonfootprint,fuelconsumptionandconsequenthightransportationcosts

havetobetakenintoconsideration,togetherwiththedamagesandaccidentriskduringcarrying.

5.4.5 ConveyorBeltTransportSomecoalpowerplantsaredirectlylocatedclosetotheminingsites,whichfacilitatesthelogistical

problemofrawmaterialtransportationfromtheminingareatothestorageandend-userfacilities.Insuch

cases,ifhillyterrainmakesroadsunsuitableforthispurpose,conveyorbeltsareinstalled.

Themainadvantageofadoptingthistechnologyisthereliability(conveyorbeltsarealmostmaintenance

free).However,installingsuchamachinerydoesnotrepresentaflexiblesolution,carryingcoalonlyfrom

onelocationtoanotherone(Vogel&Roberts,1979).

5.4.6 KPIsevaluationforcoaldistributiontechnologiesIn,thetablebelow,themainKPIsforacomparativeassessmentbetweentheanalysedtechnologiesfor

coaltransportationanddistributionisproposed.TheseKPIscanhelpcharacterisingthevarious

transportationmodes.

ThemainsourcesusedtocompleteTable12comefromthesamereferencesquotedineachspecific

technologysection.



Table12:KPIsevaluationforcoalT&D

KPI Type CoalSlurryPipelines CoalLogPipelines RailroadTrains Barges Trucks Conveyor

Belts

Environmentalimpact Majorimpacttypegenerated

Yardimpactduring

installation,landscapeimpact,

highwaterdemand

Yardimpactduringinstallation,

landscapeimpact,waterdemand

Logisticissues,electricitydemand

GHGemissions GHGemissions -


Costoftransported

energy€/(ton*km)

0,4 0,2 0,007 0,005 0,09 0,015

Performanceindex

Efficiency(Energy

carried/(carried+consumed+losses))

0,98(considering2000km

transportation)

0,99(considering2000km)

0.99(considering2000km)



0,97(considering

1km)

Technologicalregime InfrastructureLifespan(years) 30 20 30 15 5

Technologicalregime Maturityoftechnology Medium-High Medium High High High High


locationsLow Medium Low High Low

Politicalcommitment AvailableGrants&PolicySupport - - - - - -


Degreeofacceptanceofthe

technologyLow-Medium/decreasing



AsshowninTable12,coalpipelineshavehighercostscomparedtoothermoretraditionalcoaltransportationmethods.Thesehighcostsareduetothecomplexcrushinganddewateringoperationsthatareperformedbeforeandafterthetransportationrespectively,whichhavetobeaddedinfrastructure(pumpingstationsandpipelines)installationcosts.Theirmainadvantageisthepossibilitytobeusedwhereotherinfrastructuresarenotpossibleortooexpensivetobebuilt.

Ontheotherhand,transportationcostsarelowerwhentheyaredistributedoveralargeamountofcoal.Asabargecancarryupto30,000tonsinasingleshipping,thismakesitthecheapestwaytotransportthisprimaryenergysource.However,theselowcostscomewiththeverylowflexibilityofthistechnology,needinginfrastructurelikeharbours,loadinganddownloadingfacilities,etc.Landtransportationmethodsliketrucksorrailwaysarecertainlymoreflexible.

Fuel-basedtechnologies(i.e.,bargesandtrucks)arecharacterisedbythelowestefficienciesbecauseofthehighconsumptionfortheamountofcoalcarriedinasinglejourney.Moreover,fromanenvironmentalpointofview,theyhavethehighestcarbonfootprint.

Slurryandlogpipelinemethodsarequiteinnovativefromatechnologymaturitypointofview.

6 Energystorage

Energystorageinvolvesthecaptureoftheenergyproducedatonetimetobeusedatalatermoment.Tomakethispossible,theenergycapturedneedstobeconvertedfromformsthatmightbedifficulttostoretomorestorableforms.

Theconversionisdonewithvarioustypesoftechnology,whichcanprovideadifferentrangeofstorages,fromlongtoshortterm.Storageisusedattimeswhenconsumption,thatcannotbedeferredordelayed,exceedsproduction.Inthisway,electricityproductiondoesnotneedtobedrasticallyscaledupanddowntomeetmomentaryconsumptionbutinstead,transmissionfromacombinationofgeneratorsandstoragefacilitiesismaintainedatamoreconstantlevel.

Tomeettheneedsofthepopulation,whichisbeingprogressivelysensitisedtotheissuesaroundenergyconsumption,alargenumberofmanufacturerslaunchedrechargeablebatterysystemsforstoringenergy,generallytoholdsurplusenergyfromhomesolar/windgenerationplants,thatcouldbeintegratedintothetraditionalsysteminordertoallowhomeuserstostore,monitorandmanageelectricity.

Gridenergystorage(alsocalledlarge-scaleenergystorage)canbedefinedasagroupofmethodsandsystemsusedtostoreelectricalenergywithinanelectricalpowergrid.AsmartgridcommunicationinfrastructurethatenablesDemandResponse(DR),canbeused,alternativelyandcomplementary,toachievethesameeffect:infact,boththesetechnologiesshiftenergyusageandtransmissionofpoweronthegridfromonetime(inwhichitisnotusefulanditwouldbewasted)toanother(inwhichit'srequired).

Thepurposeofanyelectricalpowergridistobalanceenergyproductiontoenergyconsumption,byfollowingandbeingflexibletotheirvariationovertime.Anycombinationofenergystorageanddemandresponsehasitsadvantages.Someexamplescanbefoundbelow:

• electricitygeneratedbyintermittentsourcescanbestoredandusedlater,otherwiseitwouldhavetobetransmittedforsaleelsewhere,orsimplywasted



• fuel-basedpowerplants,suchascoal,gas,oil,canbemoreefficientlyandeasilyoperatedatconstantproductionlevels

• transmissioncapacityorpeakgeneratingcanbereducedbythetotalpotentialofallstorageplusdeferrableloadssavingexpenseofthiscapacity

• Reducingthevarianceintheenergyproductionneedsreducestheproductioncosts,resultinginamorestablepricingforthecostumersandahigherincomefortheutilities

• Incaseofemergency,vitalneeds(suchaselectricityinanhospital)canbemetreliablyevenwithnotransmissionorgenerationgoingon

Energystorageisparticularlyimportantinanenergysystemdominatedbyrenewablesources,suchastheoneEUisaimingat.Energyproducedfromphotovoltaicandwindsourcesinherentlyvaries:theamountofelectricalenergyproducedvariesaccordingwithtime,season,dayoftheweek,andweather.Therefore,renewablespresentspecialchallengestoelectricutilities.Whilehookingupmanywindsourcescanreducethevariability,actuallysolarisconsideredareliablesourcebutisnotavailableatnightandtidalpowershiftswiththemoonthereforeisneverreliablyavailableonpeakdemand.

Inanelectricalpowergridwithoutenergystorage,energysourcesthatrelyonenergystoredwithinfuels(coal,gas,oil,nuclear)mustbescaledupanddowntomatchtheriseandfallofenergyproductionfromintermittentenergysources.Whilecoalandnuclearplantstakeconsiderabletimetorespondtoload,oilandgasplantscanbescaledupwhenwindintensitydiesdownquickly.Utilitieswithlessgasoroilpowergenerationare,forthisreason,morereliantondemandmanagementandgridstorage.

Energystoragesystemsmaybringbenefitsonasmallorlargescale:

• Commercialconsumersconnectstoragewithrenewablesordemandresponse.

• ResidentialconsumersmatchstoragewithPVinstallationsinordertocollectmaximumbenefitfromsolarsystems.

• Utilitiesusuallyusestorageasreservecapacitynotonlytoholdpeakloadsbutalsotoimprovegridresilience.

Despitethefactthatbasictechnologieshavebeenaroundforyears,energystorageisstilladifficultproblemtosolve.Inrecentyears,though,therehavebeenmanyimprovementsintermsofcost,effectivenessandsafetythatmakesitpossibletohopeforaspeedupinfutureimplementationtowardsaDGsystem.

6.1 ElectricityEnergystoragesolutionscanbedeployedindifferentapplications.Intermsofthetechnologiesthemselves,someofthemcanbeusedacrossarangeofapplications,whileothersareuniquelyappropriatetospecificapplications.Akeyfactortosuccessistoincreasethemarketpresenceofenergystoragetechnologies,whichwillresultincapacitymatchingtheapplicationofthetechnologyinthebestwaypossible,especiallyintermsofeffectivenessandeconomy.

6.1.1 Pumped-storagehydroelectricity

TheelectricpowersystemsforloadbalancinguseatypeofstoragenamedPumped-StorageHydroelectricity(PSH,orPHES).Themethodaccumulatesenergyusingthegravitationalpotentialenergyof



water,pumpedfromalowerelevationreservoirtoahigherelevation.Inordertorunthepumpsalow-costoff-peakelectricpowersourceisused.Thestoredwaterisreleasedthroughturbinestoproduceelectricpowerduringperiodsofhighelectricaldemand.Despitethelossesthepumpingprocessmakesintermsofnetconsumptionofenergyoverall,thesystemisabletoincreaserevenuebysellingmoreelectricityduringperiodsofpeakdemand,whenelectricitypricesaremoreexpensive.

Electricitymustbeusedasitisbeinggenerated,orconvertedinstantlyintoanotherformofenergysuchaskinetic,potentialorchemical.Theuseofpumped-storagehydroelectricityrepresentsatraditionalwayofstoringenergyonalargescale.SomeareasoftheworldsuchasNorway,WalesintheUnitedKingdom,aswellasWashingtonandOregonintheUnitedStates,haveusedthetopographytheretostorelargequantitiesofwaterinelevatedreservoirs,usingexcesselectricityduringperiodsoflowdemandtopumpwaterupintotheirreservoirs.Thefacilitiesthenreleasethewaterwhichpassesacrossturbinegeneratorsandconvertsthestoredpotentialenergybacktoelectricityduringelectricaldemandpeaks.

Theworld’slargestpumpedhydroplanthasacapacityof2,862MW(VV.AA.,2012b:31),whichisaproofthatpumpedhydroplantshaveahugepotentialintermsofenergyandpowercapacity;theycanaccommodateenergyspikesassociatedwithgenerationfromintermittentrenewableenergysources.Pumpedhydropresentsseveraladvantages:acycleefficiencyofapproximately75%,alonglifespan,andnolifecyclelimitations,givenacontinuoussupplyofwater.Anothersignificantadvantagetoconsideristhefactthatenhancinganexistingprojectcanresultinlargesavingsoncapitalexpendituresandatthesametimereduceenvironmentalandplanningissues(VV.AA.,2012b).

6.1.2 Compressedairenergystorage(CAES)

(CAES)isaprocesstostoreenergygeneratedatonetimeinordertobeusedinanothermomentusingcompressedair.CAESplantsarelargelyequivalenttopumped-hydropowerplantsintermsoftheirapplications,outputandstoragecapacity.

Thetechnologystoreslow-costoff-peakenergy,intheformofcompressedairinanundergroundreservoir.Theairisthenreleasedduringpeakloadhoursandheatedwiththeexhaustheatofastandardcombustionturbine.

Thisheatedairisconvertedtoenergythroughexpansionturbinesinordertoproduceelectricity.

OneofmostimportantcharacteristicsofCAESisthefactthathasahigh-energystoragepotential;nearlyallCAESfacilitiesareatleast100MWinsize(VV.AA.,2012b:37);theuseofexistinggeologicalstructuresforstoragereducesenvironmentalimpactsandfootprintsofCAESfacilities.

Ontheotherside,CAESrequiresasuitablesitethatmustfulfilspecificundergroundgeologicalcharacteristics(verylargesubterraneancavernsofsuitablegeologicstrata,ancientsaltmines,orundergroundnaturalgasstorage,etc.)and,takinginconsiderationeconomiesofscaleandthecostsoffacilities,undergroundcavernshavetobequitelargeinordertomakeCAEScosteffective(EEG,2012).

6.1.3 Flywheelenergystorage

Aflywheelenergystorage(FES)isachemical-freemechanicalbatterythatharnessestheenergyofarapidlyspinningwheelandstoresitasrotationalenergy.Theenergyisconvertedbackbydeceleratingthe



flywheel.Theflywheelsystemitselfisakinetic,ormechanicalbattery,spinningatveryhighspeedstostoreenergythatisimmediatelyavailablewhenneeded.

Beingacompletelymechanicalsystem,flywheelsarenotaffectedbytemperaturechanges,nordotheysufferfrommemoryeffect.Theycausepotentiallylessdamagestotheenvironment,becausetheyaremadeoflargelyinertorbenignmaterials.Anotheradvantageofflywheelsisthatitispossibletoknowtheexactamountofenergystoredbyasimplemeasurementoftherotationspeed.

Flywheelsareconsideredagreentechnology,havingpracticallynoenvironmentalimpactsduetothebenignmaterialsthattheyareconstructedofandalsoduetotheirrathercompactdesign.

OtheradvantagesarerepresentedbythefactthatFlywheelsdoesnotrequireatemperaturecontrolledenvironmentandneedlittlemaintenance(Devitt,D.,2010;VV.AA.,2012b;CalnetixTechnologiesLlc.,2016).

6.1.4 Gravitationalpotentialenergystoragewithsolidmasses

Thistechnologyusesthemovementofsolidmassesfromlowertohighelevations.Solidmassestobeconsideredare:hopperrailcarsfilledwithplainearthdrivenbyelectriclocomotives.

Energyisusedtoraiseamassthroughaheightthusstoringenergyasgravitationalpotentialenergy.Theamountofenergystoredismasstimesgravitationalaccelerationtimesheightraised.

Pumpedhydrostorageisthemorefrequentlylargescaleuseofgravitystorageincurrentuse.Theideaisthatwecanpumpamassofwaterupfromalowreservoirtoahighreservoir,andlaterretrievethisenergythroughaprocesswherewaterflowsdownandleadsawaterturbinethatdrivesageneratorproducingelectricity.Theround-tripstoragerequestsmodestcosts.

Themainproblemwithgravitationalstorageisthatitisincrediblyweakcomparedtochemical,compressedair,orflywheeltechniques.Gravitationalstoragelacksinenergydensitybutintermsofvolumepresentsadvantagessincelakesofwaterbehinddamsrepresentsubstantialstorage(StratoSolar,2016).

6.1.5 Batteryenergystorage

Powergridsatpresentarecharacterisedbyahighshareofrenewableenergysourcesandthiswillbethesameinthefuture.Thisprocessdrivestoamassivefluctuantpowerinjection,thathasthenecessitytobebalancedbybatteryenergystorage.

Batteryenergystoragesolutionsaredesignedspecificallyforfacilitatingthetransitiontonewwaysofgeneratinganddistributingelectricity.ABESsystemconsistsofelectrochemicalcellsconnectedinseriesorparallel,thatfromanelectrochemicalreactionareabletoproduceelectricitywiththedesiredvoltage.Eachcellcontainstwoelectrodeswithanelectrolytethatcanbeatliquid,solidorropy/viscousstates.Acellcanconvertenergybi-directionallybetweenelectricalandchemicalenergy(AEGPowersolutions,2016).

6.1.6 FlowBatteryEnergyStorage

Aflowbatterystoresenergyintwosolubleredoxcouplescontainedinexternalliquidelectrolytetanks.Thiselectrolytecanbepumpedfromthetankstothecellstack,whichconsistsoftwoelectrolyteflow



compartmentsseparatedbyamembrane.Theoperationconsistsbasicallyofreduction-oxidationreactionsoftheelectrolytesolutions.Duringthechargingphase,oneelectrolyteisoxidisedattheanodewhileanotherelectrolyteisreducedatthecathode,andatthesametimetheelectricalenergyisconvertedtotheelectrolytechemicalenergy.Duringthedischargingphasetheprocessisreversed.

Thistechnologyissimilartobothafuelcellandabattery–whereliquidenergysourcesareabletoberechargedwithinthesamesystem,aswellastocreateelectricity.

Flowbatteriescanbealmostimmediatelyrechargedwhentheelectrolyteliquidisreplaced,whileatthesametimerecoveringthematerialconsumedforre-energisation.

Redox,hybridandmembranelessrepresentdifferentclassesofflowcellsthathavebeendeveloped.Themaindifferencebetweenconventionalbatteriesandflowcellsisthatenergyisstoredastheelectrodematerialinconventionalbatteriesbutastheelectrolyteinflowcells(EnergyStorageAssociation,2016).

6.1.7 Capacitorandsupercapacitor

Acapacitoriscomposedofatleasttwoelectricalconductors(normallymadeofmetalfoils)separatedbyathinlayerofinsulatorthatcanbemadeofglass,ceramicsoraplasticfilm.Inordinarycapacitors,electronsaremovedfromoneelectrodeanddepositedontheotherandthechargeisseparatedbyasolid.

Comparedtoconventionalbatteries,capacitorshaveshorterchargingtimesandahigherpowerdensity.Intermsofstoringsmallquantitiesofelectricalenergy,capacitorsarethemostappropriateaswellasforconductingvaryingvoltageoutputs.

Supercapacitors(alsocalledanElectricdouble-layercapacitor)orUltracapacitorsareatypeofhighpowerhighenergydensitycapacitor.InSupercapacitorsinsteadofasoliddielectric,thetwoelectrodesareseparatedbyaliquidelectrolyterichinions.Electricalenergyisstoredinsupercapacitorsthroughtwostorageprinciples:thedistributionofthetwotypesofcapacitancedependsonthestructureandmaterialoftheelectrodes;aswellasthestaticdouble-layercapacitanceandelectrochemicalpseudocapacitance(Quora,2016).Supercapacitorscanhaveboththecharacteristicsofelectrochemicalbatteriesandtraditionalcapacitorsthanktotheirstructures.

Therearethreetypesofsupercapacitorsbasedonstorageprinciple:

• Double-layercapacitors(EDLCs)–withactivatedcarbonelectrodesorderivativeswithmuchhigherelectrostaticdouble-layercapacitancethanelectrochemicalpseudocapacitance(Jayalakshmi,M.andBalasubramanian,K.,2008)

• Pseudocapacitors–withtransitionmetaloxideorconductingpolymerelectrodeswithahighelectrochemicalpseudocapacitance

• Hybridcapacitors–withasymmetricelectrodes,oneofwhichexhibitsmostlyelectrostaticandtheothermostlyelectrochemicalcapacitance,suchaslithium-ioncapacitors

Supercapacitorsdemonstrateamuchlongerlifetimethanbatteries.Infacttheenergydensityofsupercapacitorsisgenerallyonanorderofmagnitudelessthanthatofconventionalbatteries,butthepowerdensityisgenerally1-2ordersofmagnitudegreater.Sincesupercapacitorsdonotrelyonchemical



changesintheelectrodes(exceptforthosewithpolymerelectrodes)lifetimesdependpredominantlyontherateofevaporationoftheliquidelectrolyte(Quora,2016).

6.1.8 SuperconductingMagneticEnergyStorage

SuperconductingMagneticEnergyStorage(SMES)isamethodofenergystoragebasedonthefactthatacurrentwillcontinuetoflowinasuperconductorevenafterthevoltageacrossithasbeenremoved.

TheSMESsystemstoreselectricalenergyinthemagneticfieldgeneratedbythedirectcurrent(DC)inthesuperconductingcoil,cryogenicallycooledtoatemperaturebelowitssuperconductingcriticaltemperature,inordertohavenegligibleresistance.Ingeneral,whencurrentpassesthroughacoil,theelectricalenergyelectricalenergywillbedissipatedasheatduetotheresistanceofthewire;however,zeroresistancemayoccurifthecoilismadefromasuperconductingmaterial,underitssuperconductingstate(usuallyatverylowtemperature)consequentlytheelectricalenergycanbestoredwithpracticallynolosses.

DuetoitsveryhighcyclingcapacityandhighefficiencyovershorttimeperiodsSMESisverywellsuitedtohighpowershortdurationapplications.

ThebiggestproblemwithSMESatpresentisthefactthatthecoolingunitsrequireveryhighcapitalcosts(SuperPower,2016).

6.1.9 Solarfuels

Solarenergyistheworld’smostplentifulenergysource,andresearchersaroundtheworldarepursuingwaystoconvertsunlightintoausefulform.

Turningsunlightintoliquidfuelsrepresentsanotherelementofsolarresearch,becausemostpeoplearebasicallyawareofsolarpanelsthatproducehotwaterandsolarphotovoltaicsthatgenerateelectricity.

Anumberoffuelscanbeproducedfromsolarenergy,suchassolarhydrogen,carbon-basedfuelsandsolarchemicalheatpipe.Thesefuelscanbestoredandafterwardsprovidethebasisforlaterelectricitygeneration.Solarenergyiscapturedandthenstoredinchemicalbonds,innaturalandartificialphotosynthesis.Thethermochemicalapproachusesthermalprocessesforsolarfuelsproduction.Thesolarfueltechnologyatthemomentisstillatthedevelopmentstage(IFLScience,2015).

6.1.10 HydrogenstorageandfuelcellHydrogenenergystoragesystemsusetwodifferentprocessesforstoringenergyandproducingelectricity.

Acommonwaytoproducehydrogenisbyusingawaterelectrolysisunitwhichcanthenbestoredinhighpressurecontainersand/ortransmittedbypipelinesforlateruse.

Hydrogenstorageisakeyenablingtechnologyintheadvancementofhydrogenandfuelcelltechnologiesinapplicationssuchasportablepower,stationarypowerandtransportation.Hydrogenhasthehighestenergypermassofanyfuel;however,requirethedevelopmentofadvancedstoragemethodsthathavepotentialforhigherenergydensitybecauseitslowambienttemperaturedensityresultsinalowenergyperunitvolume.



Highdensityhydrogenstorageisasignificantchallengenotonlyfortransportationapplicationsbutalsoforstationaryandportableapplications.Currentlyavailablestorageoptionstypicallyrequirelarge-volumesystemthatstorehydrogeningaseousform.NowadayshydrogenEESwithcelltechnologyinthedevelopmentanddemonstrationphase(Energy.Gov,2016).

6.1.11 Cryogenicenergystorage(CES)CESisaprocessthatcomprehendstheuseoflowtemperatures(cryogenic)liquidssuchasliquidnitrogenorliquidairasenergystorage.Usuallyatnightwhenthecostsarelower,electricityisusedtocoolairfromtheatmosphere to -195°C,which is thepointwhere it liquefies.The liquidair canbekept fora long timeatatmosphericpressureinalargevacuumflask.Theliquidairispumpedathighpressureintoaheatexchanger,thatactsasaboiler,duringperiodswhentherequestofelectricityishigher(HighviewPower,2016).

Intheprocesstoheattheliquidandturnitbackintoagashotwaterisusedfromanindustrialheatsource,or from atmospheric air at an ambient temperature. This results in a significant increase in volume andpressurethatisusedtodriveaturbinetogenerateelectricity.

Cryogenicenergystorageoffersthefollowingbenefits:

• itusesproventechnologythat’sbeenaroundforyears

• theregulationsalreadyexist

• tanksarelesscostlyduetothefactthatStorageisatlowpressure;and

• the air it’s non-toxic and doesn’t explode and liquid air has four times the energy density ofcompressedair.

6.1.12 KPIsevaluationforelectricitystorageInthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweentheelectricitystoragetechnologiesintroducedintheprevioussectionisproposed.Duetothevariousnatureandlevelofmaturityofthetechnologiesconsidered,someindicatorsareevaluatedthroughqualitativemeasurements,inordertoprovideaclearandsimpleviewofparametersotherwisequitedifferentthroughthetechnologies.

Informationinthetablebelowcomeinthemainfromthefollowingsources;AEGPowerSolutions(2016),Energy.Gov(2016),EnergyStorageAssociation(2016),HighviewPower(2016)andVV.AA.(2012b).

Table13:KPIsevaluationforelectricitystorage

ThemeTypeof

indicator

Pumped-

storage

hydroelectricity

Compressed

airenergy

storage

Flywheel

energy

storage

Hydrogen

storageand

fuelcell

GHG

Emissions

Life-cycleGHGemissions

(gCO2eq/MWh)15.7 17.2 - -

Environmental

impact

Mainenvironmental

impact

Specialsiterequired.Landdestructionto

Specialsiterequired.SomeNOx

None

Impactsofminingand

manufacturingcatalyst



ThemeTypeof

indicator

Pumped-

storage

hydroelectricity

Compressed

airenergy

storage

Flywheel

energy

storage

Hydrogen

storageand

fuelcell

createreservoir.

emissionscanoccur.

Environmental

impactLevel Medium-High Medium - Medium

Capital

investment

cost

Energy-relatedcost(€/kWh)

75 5 1600 15

Performance

indexEfficiency 55-85% 40-70% 90-95% 20-40%

Technological

regime


30 30 20 6

Technological

regime


High Medium High Low

Political

commitment

AvailableGrants&Policy

support

ElectricityDirective2009/72/ECdoesnotmentionstorageissue,severalMemberStatesgivetheirTransmissionSystemOperators

themanagementofelectricitystorage.

Publicopinion

Degreeofacceptanceandsuccessofthetechnology

High Medium Low -

Astheabovetablesuggests,heatstoragetechnologiesappeartohavearelativelylowimpactontheenvironment.Themaindifferencebetweentheproposedtechnologygroupsareintermsofthecapitalcostsinvolved:sensibleheatstoragemethodsarelargelythecheapest,whilstPCMandthermo-chemicalstoragerequirehigherexpensesfortoolspurchasingandinstallation.

Technicalperformancesaregenerallyhighforthesetechnologies,withthehighestvaluesdemonstratedinthethermo-chemicalstoragemethods,withefficiencyratingrecordedupto100%.

Anyway,despitethegoodperformancesand“green”aspectoftheseprocesses,theyarenotatfulltechnologicalmaturenessandthereforedonotallowthemtoreachlargemarketshares.Also,publicopinionisnotcompletelyaccepting,orevenawareofthesetechnologiesyet.

6.2 OilSinceoilisaliquid,itsstoragedoesnotpresentasmuchdifficultiesastheotherthreecategoriesconsideredinthischapter,suchaselectricity,gasandheat.Nevertheless,oilstorageneedstobeperformedwithcareinordertoavoidenvironmentalcontaminationandoilloss.Forthisreason,onlyabriefoverviewonstoragetanksisgiveninthefollowingsection.



6.2.1 Storagetanks

Storagetanksareimportantformanyindustriesandmayassumedifferentsizesandshapes.Thevertical,cylindricalstoragetankshapeisthemostcommonused.Infact,largetankstendtobeverticalcylindrical.Somespecialapplicationsmayrequiretankstoberectangular,intheformofhorizontalcylinders,orevensphericalinshape.Horizontaltankscanbeusedaboveandbelowground,andaregenerallysmallstoragetanks.InmostcasesHorizontalcylindersandspheresareusedforfullpressurestorageofchemicalproductsorhydrocarbon.

Thetypeofproductsproducedinrefineriesallovertheworldhavechangedsignificantly.Thestoragetankindustryhadtofacenewchallengesinordertoadapttothesechanges,especiallyintermsofthephysicalandchemicalpropertiesofproductsthemselves.Thepetroleumindustrycontinuestogivegreatimportancetoenvironmentalandsafetyrequirementsintheprocessofdesignandselectionofstoragetanks.

Anatmospheric storage tank (AST) is a container forholdinga liquidatatmosphericpressure.TherearedifferenttypesofASTinuse:toptanks(OTT),fixed-rooftanks(FRT),fixed-rooftanks(FRT),externalfloating-rooftanks(EFRT),orinternalfloating-rooftanks(IFRT).Dependingonthecharacteristicsoftheproduct,aclosedfloating-rooftank(CFRT)mayalsobeputintouse(PetroWiki,2013).

6.3 GasNaturalgashasalwaysbeenconsideredaseasonalfuelsinceitsdemandchangesaccordingtothechangingweatherpatternsthroughouttheyear.Theneedforheatinbothresidentialandcommercialsettingsduringwintermonthsnecessitatesahigherdemandofnaturalgascomparedtosummermonths.

The storage of natural gas is crucial since excess gas supply built up during the summer periodmay beavailabletosatisfytheconsumerneedsduringwintertime.Basicallyinordertorespondthisloadvariations,theGasisinjectedintostoragetanksduringperiodswherethedemandislowerandthenwithdrawntomeetperiodsofpeakrequest.Thismethodisveryimportantformaintainingacontractualbalance.

Inordertomaintainthevolumedeliveredandwithdrawnfromthepipelinesystem,shippersusestoredgas.Otherwise,theywouldrisksubstantialpenaltiesincasesofimbalancesituations.

Naturalgasstorageplaysacrucialroleinmaintainingthereliabilityofsupplyandsmoothingoutindustryresponsestochangingconsumerdemand.Nowadaysnaturalgasstorageisalsousedforcommercialreasonsbyindustryparticipantssincetheyarestoringgaswhenpricesarelow,andwithdrawingandsellingitwhenpricesarehigh.

6.3.1 Depletedgasreservoir

This is the formof underground storage that ismost frequently used. It is also the cheapest, easiest todevelop, operate andmaintain of the three types of underground storage. Depleted reservoirs are theformationsthathaveproducedalltheirrecoverablenaturalgasandhaveanundergroundformationwithcertaingeologicalcharacteristicsalreadyknownthatallowtheprocessofholdingnaturalgas.Thepossibilitytouseareservoir forstorageallowsforthe industrytotakeadvantageoftheextractionanddistributionequipmentthatare leftonthegasfieldduringthephaseofproduction.Thiswillbe importanttoreducestart-upcostsintheconversionprocessofadepletedreservoirintoastoragefacility(NaturalGas,2016).

6.3.2 Aquiferreservoir

Aquifers are rock formations that act as natural water reservoirs characterised porous and permeabletopographiesofthelandscapesinwhichtheyoccur.Insomespecificcasestheymaybeusedfornaturalgasstorage.Aquifersarethemostexpensivetypeofundergroundstorageduetothefactthatthegeologicalfeaturesarenotknowninadvance,whichimpliesasignificantinvestmentoftimeandresources.Othercosts



needtobeexpendedtodeterminetheaquifer’ssuitabilityfornaturalgasstorage. Inthecasewheretheaquiferprovestobesuitablealltheassociatedinfrastructuremustbeimplemented,includingtheinstallationofwells,extractionequipment,pipelines,dehydrationfacilities,andpossiblycompressionequipment.

In some cases, Aquifers development may require twice the amount of time needed in comparison todepletedreservoirsforsuitablestoragefacilities.Environmentalrulesandrestrictionsshouldalsobetakingintoconsiderationincreasingtimeandcosts.Environmentalrulesandrestrictionsshouldalsobetakinginconsiderationincreasingtimeandcosts(EIA,2016b;NaturalGas,2016).

6.3.3 Saltformation

Undergroundsaltformationsarebasicallyapplicabletonaturalgasstoragesincesaltcaverns,onceformed,allowonly a small quantity of injected natural gas to escape from the formation, unless it is specificallyextracted.Thisoptionfornaturalgasstorageisveryresilienttoreservoirdegradationduetothefactthatthepropertiesofthewallsareconsistentwithsteelandconsequentlyimpervioustogas.Usuallysaltcavernsareformedoutofsaltdepositsthatalreadyexist.Acavernisdevelopedwithintheformationassoonasitisconsideredappropriatefordevelopmentasagasstoragefacility.Thisconsistsofusingwatertodissolveandpulloutacertainquantityofsaltfromthedepositleavingalargeemptyspaceintheformation.Thisprocessalsoinvolvesdrillingawellintotheformationandcyclinglargequantitiesofwaterthroughthecompletedwell.Thewater,nowsaline,isthenpumpedbacktothesurface.Thisprocess,called“saltcaverleaching”,canbequiteexpensivebutoffersthefollowingadvantages:saltcavernsprovidesanaturalgasstoragevesselwithhighdeliverabilityandwhencomparedwithotherstoragetypescushiongasrequirementsarequitelow,approximately33%oftotalgascapacity(NaturalGas,2016).

6.3.4 LNGstoragetanks

WithregardstothestorageofLiquefiedNaturalGas(LNG)thetypeofstorageusedisLNGstoragetanks,which can store LNG at the significantly low temperatures of -162°C (-260°F). They may be placedunderground,abovegroundorinLNGcarriers.LNGisbasicallynaturalgascooledtoaliquidstate.Naturalgascondensestoa liquidwhenit iscooledtoatemperatureof-256°Fatatmosphericpressure(UHIELE,2016).Averycleanproductresultswithoxygen,carbondioxide,sulfurcompoundsandwaterbeingremovedasthenaturalgasiscooledtoaliquidstateduringtheliquefactionprocess.Liquefiednaturalgashasseveraladvantages:itallowsforthereductionofitsvolumebyabout600to1,makingitpossibletotransportnaturalgasbytanker.Also,re-gasificationanddeliverytomarketsbecamepossibleaftertheabilitytostoreimportedLNGanddomesticproductionbecamepossible(USDept.ofEnergy,2005).Theamountofcostsinvolvedareusuallyhighsinceit’snecessarytoconstructfacilitiesfortheprocessofliquefaction,topurchasespecificLNGshipsandtobuildre-gasificationfacilities.

6.3.5 Pipelinecapacity

Aprocesscalledlinepackingallowsgastobetemporarilystoredinthepipelinesystem.Theconceptinvolvesaprocesswherebythereisanincreaseinthepressuretopackmoregasintothepipeline.Inperiodswhenthedemandismoreintensive,higherquantitiesofgascanbewithdrawnfromthepipelineinthemarketareatoconformwiththequantityinjectedattheproductionarea.Thelinepackingprocessisimportanttorespondtothetimeperiodafterdemandpeaksandduringoff-peakperiods.Wearetalkingaboutashort-termsubstituteforalimitedperiodoftimefortraditionalundergroundstorage(EIA,2016b).

6.3.6 Gasholders

Agasholderisacontaineroflargedimensions,sometimesknownasgasometer,thatstoreslargevolumesofgasusuallyfromnearbygasworks.Thevolumeofthecontaineriscloselyrelatedthequantityofstoredgas.Thegasholdersmaystoreuptotwomillioncubicfeetofgas,justtoconceptualisethisthatisenoughtosupply2,400homesforafullday.Duetodevelopmentsingaspipetechnologygasholdersarenolonger



neededandnowtendtobeusedmostlyforbalancingpurposesratherthanforstoringgasforlateruse(TheTelegraph,2016).

6.3.7 LinedRockCavern

LinedRockCavern(LRC)gas-storageisaninnovativetechnologythathasbeenunderdevelopmentinSwedensince1987.Theevolutionpathpassedthroughseveralphasessuchastechnicalstudies,laboratorytestingandfieldtests.Itpresentssomedifferenceswhencomparedtocurrentstoragetechnologiessinceitprovidesmajorflexibilityasfarasthemanagementofsuppliesatlocalandregionallevelareconcerned.Theconceptistousearockmasstoserveasapressurisedvesselintheprocessofcontainingstorednaturalgas,withmaximumpressuresfromabout15MPato25MPa.Thisidearequirestheexcavationoflargeandverticallycylindricalcavernswithdiametersrangingfrom20mto50m,withheightsrangingfrom50mto115m.12-30millionNm3(400-1,100millioncubicfeet(MMcf))ofcapacityfornaturalgasstorage.Wearetalkingaboutcavernsfrom100mto200mbelowground(Brandshaug,Christianson,andDamjanac,2001).

Incaseswherethestoragepressureislowerthanthatinthepipelineitself,theinjectionintothecaverntakesplacefromthepipelinethroughaprocessofflowcontrol.Otherwisecompressionisusedtoboostgaspressure.Anairorwatercoolerisusuallyintheprocessofcoolingthegas,aftercompression,andthemomentbeforetheinjectionofthegasinsidethecavern.Thegascanbeinjectedbackintothecavernduringthegasinjectionifthepressurelevelsinthecaverndemonstratetobesuperiorthanthoseinthepipeline.Thisprocesswilltakeplacewiththehelpofaseparatecompressorafterbeingcirculatedthroughacooler.Itcanalsocontributetoriseintheworkinggasvolumeinthecavern.Arefrigerationunitcanbeusedinordertocooltherecirculatedgastoalowertemperatureforthepurposeofincreasingevenfurthertheworkinggascapacity(SofregazUSInc.,&LRC.,1999)

6.3.8 Hydrates

Thediscoveryoflargegashydrateaccumulationsrepresentedanimportantresultinthesearchforpossibleenergysourcesintheearth.Gashydratesarecrystallinesubstancesofwaterandnaturalgaswhereasolidwater-latticeholdsgasmoleculesinclathrate,orinastructuresimilartoacage.Basicallythestorageofnaturalgaswouldrequirenothinglessthatthesynthesisofthehydrateanditsregasification.Thisprocesscanbeveryusefulduetothefactthatthedensityofnaturalgashasasignificantinfluenceasfarasthereductionofspacerequestsforgasstorageareconcerned.

Onlyalimitednumberofgashydrateaccumulationshavebeenanalysedindetail,anditmustbetakenintoconsiderationthatonlyin50areasaroundtheworlddoesthisenergysourceappeartooccur.Furtherresearchintogashydratesisnecessaryforasignificantbreakthroughtooccur(Altenergymag.com,2007).Theavailabilityofproduciblegashydrateresourcesandthecosttoextractthemaretwocrucialelementstotakeintoconsiderationtodeterminetherealimportanceofthisenergyresourceandhowitmaybeusedinresponsetotheworld’senergydemands.Actuallyconsiderabledoubtsstillexistabouttherealpotentialofgashydratesasanenergyresource.Thelimitationsincludeaccessibility,reliableuseandcompatiblecosts(Oellrich,2004).

6.3.1 KPIsevaluationforgasstorage

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthegasstoragesolutionsintroducedintheprevioussectionareproposed.Asithappenedforelectricitystoragesystems,qualitativemeasurementsareusedinmultipleKPIs,inordertocreateauniformviewofthesetechnologiesgiventheirverydifferentcharacteristicsandreadinesslevels.

Themainsourcesthatinformthetablebelow,comefromEIA(2016a),EIA(2016b)andNaturalGas(2016).



Table14:KPIsevaluationforgasstorage

Theme TypeofindicatorDepletedgas

reservoir

Aquifer

reservoirSaltformation

LNGstorage

tanks

Environmental

impact

Mainenvironmental

impact

Landscapeimpactduetoextractionequipmentinstallation

Landscapeimpactduetoextractionequipmentinstallation

Disposalofsaturatedsaltwaterduring

mining

8-10%ofgaslossesinLNGproduction,2-2.5%losses

inregasification

Environmental

impactLevel Medium Medium Medium-High Medium

Capital

investment

cost

Energy-relatedcost($/kWh)

Medium High Low 0.01

Performance

indexCapacity 109m3

Comparabletodepletedgasreservoirs

1.5-3*108m3 450*106m3

Performance

index

Charge/Dischargetime

120-200days/60-120days

120-200days/60-120days

20days/5-20days

2.6*106

m3/h

Technological

regime


30 30 30 30

Technological

regime


High High High High

Political

commitment


GasDirective2009/73/ECmentiongasstorageasoneofcoreelementsofthegasdistributionsystem.

Enhancingenergysecuritybysustaininggasstoragetechnologies.27projectstobefinishedwithin2020,€17billiongranted.

Publicopinion


technologyLow Low Low Medium

ThetableaboveshowsaKPI-basedcomparisonbetweendifferentproposedgasstoragetechnologies.Ascanbeseen,themainenvironmentalissuerelatedtotheseoperationsisintermsoflandscapeimpactresultingfromthepresenceofsignificantcharge/dischargeinstallationsrequired.Moreover,LNGproductionreleasesacertainamountofnaturalgasemissionsintheatmosphere.

Hugeamountsofnaturalgascanbestoredinreservoirs(includingdepleted,aquiferandsaltformationtypes),whilstLNGtechnologyhaslowercapacitiesandissuitableforsmallergasvolumestorageoptions.



Whencomparedtosaltformationstoragefacilities,depletedgasandaquiferreservoirsrequirelongerchargeandextractiontimes,andthelowerinvestmentcostsmakeitamoreaccessibletechnology.

Referringtothepublicopinionmoregenerallypeopleappeartoseetheenvironmentalandlandscapedrawbacksassociatedtogasreservoirs,thoughLNGtechnologyseemstobemoreacceptable.

6.4 CoalThesameapproachappliedforoilstoragecanbeproposedforcoalstorage.Coalsuppliesaremucheasiertostorethangas,electricityorheat,andthemainfocusincoalstackingisduetoproductivitycalculationsandtheneedtoavoidairandgroundpollutionfromrain.Inthefollowingsectionanoverviewofcoalstackingtechniquesispresented.

6.4.1 Coalstacking

Figure11Coalstackingposition(RSTPS,2012)

Coalisamaterialthatoffersthepossibilitytobestoredinlargequantitiesinpreparationforsomespecificfutureneeds.Trucksorwagonsarethemainmeansoftransportusedtotaketheproducedcoaltothesestorageareas.

Climateconditions,thedimensionanddesignofthestoragerequiredrepresentthemainfactorsthatinfluencethechoiceforthemostsuitabletechniquestouseindifferentcountries.Stackingcanbedoneinopenareasbutalsooncoveredstackareasorinclosedcoalsilos.Thefirstcaseismorefrequentlyused.Thelongperiodstoringinopenareascancausesomeproblemsduetothespontaneouscombustionofcoalasaconsequenceofthegascreatedinthestackpile.Thismayariseduetoanumberdifferentfactors:thefirstcategoryrepresentsthosethatarepossibletobecontrolled(forexamplethemanagementofthecoalstorageinstockpiles,silos/bunkersandmillsinthepowerplant)aswellasthealltheproceduresrelatedtothecoaltransport.Ontheotherhand,therearethosefactorsthatcannotbecontrolledsuchtheambientairconditionsandthecoalitself.

Coalisstoredforalimitedperiodoftime,giventhechanceofself-heatingisdirectlyconnectedtoitsstorageconditions.Theproblemwithlong-termsilo/bunkerstoragemaybesolvedwithventilationplacedatthetopofthesiloorbunkertoremoveallgasesreleasedfromthecoalorbysealingthesilo/bunker.Stockingprocessdemandsconsciouslyandrespectoftherulesotherwiseunpleasantsituationscancomeout(Oktenetal.,2013;Radhakrishnane,2012).



6.5 HeatstorageThermalEnergyStorage(TES)isaproventechnologywithoverthreedecadesofsuccessfulinstallationsandstablethermalenergycapacity.Thisprocessisdonebyheatingorcoolingastoragemediuminordertousetheenergyforlateruseinpowergenerationandalsotoforheatingandcoolingapplications.

TESsystemscanbedividedalongthreedifferenttechnologies,eachonewithitsowncharacteristicsanddifferentassociatedcosts:sensibleheatstorage(e.g.water,sand),latentheatstorageusingphasechangematerials(e.g.fromasolidstateintoaliquidstate)andthermo-chemicalstorageusingchemicalreactionstostoreandreleasethermalenergy.

Thefirstsystemoffersstorageefficienciesbetween50-90%andcapacityrangingfrom10-50kwh/t,accordingtotheheatlevelofthestorageandthermalinsulationtechnologies(VV.AA.,2013c).

Thesecondsystem(PCMs)isabletoofferstorageefficienciesfrom75-90%andasuperiorstoragecapacity.Asfarasregardsthermo-chemicalstorage(TCS)systemscanreachstorageefficienciesfrom75%-100%,storagecapacitiesofupto250kwh/m3withoperationtemperaturessuperiorto300°C(VV.AA.,2013c).

Thesensibleheatstoragesystemisthemosteconomical,whiletheothertwooptionshavehigherassociatedcostsandareconsideredeconomicallyviableonlyforapplicationswithhighnumbersofcycles.

TEStechnologiesfacesignificantobstaclesaroundmarketentry:TCSandPCMbothneedtoimproveintermsofstablestorageperformance,linkedtoassociatedmaterialproperties,thoughthemainbarrierisinrelationtothecostsrequired.

Ontheotherhand,thestorageofthermalenergypresentsthefollowingadvantages:includingitsimportantroleincontributingtothereductionofCO2emissions;theprocessofreplacingheatandcoldgenerationfromfossilfuels;inreducingtheneedforpowerduringpeakperiodswhencostsarehigher;andincontributingtoheatproductioncapacity.

6.5.1 SensibleHeatStorage

SensibleHeatStorage(SHS)concernstheprocessofstoringheatinaliquidorsolidforthepurposeofusingitagainatalatertime,whenneeded.SHSoccursbyavoidingthephasechangeoftheliquidorsolid,addingheattothestoragemediumandincreasingitstemperature.Watercanbeusedinco-generationplantsandtostoreenergyfromheatingsystemsbasedonsolarenergyandrepresentsthemostcommontypeofstoragemediumforSHS.Watertankstorageisacost-effectivestoragesolutionthatcanbecarriedoutinsmallbuildingsystemsandbigplants(GENI,2012).

6.5.1.1 Seasonal thermal energy storage

Seasonalthermalenergystoragereferstostorageofheatorcoldforperiodsoftimethatmaylastseveralmonths.Thermalenergyoffersthepossibilitytobecollectedineverypossiblemomentandtobeusedeveninotherseasonsoftheyearwhentheneedofenergyishigheranditsadvantagescanbeunderstoodasfollows:

• Undergroundthermalenergystorage:itcanbeusedforbothheatandcoldstorage.

• Surfaceandabovegroundtechnologies,typicallyinsulatedwatertankstoragesolutions.

Thetypesofseasonalthermalenergystoresare:tankthermalenergystore(HW),pitthermalenergystorage(PTES),boreholethermalenergystore(BTES)andaquifer-thermalenergystore(ATES).Asfarasconstructioncostsareconcerned,HWusuallyhashighercostswhileATESisthecheaperoption.

Futurecharacteristicsforlargescaleseasonalthermalenergystorageneedtoaccountforthefollowingfactors:pricesshouldbecheapergivenexpectedpricesarelessthan50€/m³,sealingbypolymericfoilandfreeflowingevacuatedinsulationmaterial(Kerskes,2011).



6.5.1.2 Steam accumulator

Asteamaccumulatorisaninsulatedsteelpressuretankcontaininghotwaterandsteamunderpressure.Theconceptofasteamaccumulatoristoreleasesteamwhendemandishigherthantheboiler’scapacityinordertoensuresupplyintheperiodwhenthedemandislowtoacceptsteam.

Eventhoughsteamaccumulatorsdonothaveasignificantapplicationinmodernindustrymoregenerally,theyhavebeeninstalledinsomeindustries,forexampleinbio-technology,medicalandindustrialsterilisationprocessesandintheprintingandfoodmanufacturingsectors.Steamaccumulatorshavealsobeeninstalledinmoretraditionalindustriessuchbreweriesanddyehouses.

Modernboilershavebecomesmallerandtherehasalsobeenanincreaseintheuseofsmallwater-tubeboilers,coilboilersandannularboilers,allofwhichareefficientthoughttheydoreducethethermalcapacityofthesystemandmakeitvulnerabletopeakloadproblems.

Thepossibilitiesofpossibleapplicationsforsteamaccumulatorsareendless.Forexample,theycanbeusedwithimmersionheaterboilersorelectrodesinordertogeneratesteamduringanoffpeakperiod,storingitandthenusingitduringpeaktimes.

Intermsofefficiencyitispossibletonotethatsteamaccumulatorsaretoolsthatgivesguaranteesinthisfieldsincetheymayprovidethemostcosteffectivewayofsupplyingsteamtoabatchprocess(SpiraxSarcoLimited,2016).

6.5.1.3 Molten salt

Figure12:Moltensaltsystem(eSolarwebsite,2013)

Lookingatitsefficiencyvalues,theflexibilityandcost-effectivenessinusingmoltensaltrepresentsthebestoptionforlargescaleenergystoragesystems.Thisstoragefeature,unlikeothertechnologies,allowsforstablepowerdeliverywithouttheneedforanybackupfossilfuelsupport.Moltensaltisusedtostorethermalenergyfromsolarpowerandthenconvertitanddispatchitaselectricalpowerwhenneeded.

Duringthedaythesystempumpsmoltensaltthroughspecialconduitsoratowerthatisheated,thankstothelong-timesunexposureandheldinstoragetanksduringthenight.Thetanksstorethesaltatatmosphericpressure.Moltensaltisstoreduntilelectricityisneededindependently,whetheritisduringthedayornight.Whenthisisthecase,moltensaltisdispatchedfromthehottankwiththehelpofaheatexchangerinordertocreateextremeheatedsteamthatisfedtoturbinesinordertogenerateelectricity.



Themoltensaltneverdemandsreplacingortoppingupduringtheentireplantlifeduration(SolarReserve,2016).

6.5.2 PhaseChangeMaterials

SensibleHeatStorage(SHS)isasolutionusedquitefrequentlybecauseitinvolveslowrunningcosts,butitdoespresentsomeproblemsintermsofcharginganddischargingtemperature.Inordertosolvetheseissues,PhaseChangeMaterials(PCMs)canbeusedinstoragesystems.Actually,theystoreandreleasethermalenergyduringtheprocessofmeltingandfreezing(astheychangefromonephasetoanother).PCMsareidealproductsforthermalmanagementsolutions.Themassandlatentheatoffusionofthematerialusedwillinfluencethequantityofenergystored.

PHChavetwomainadvantages:thefirstoneisrelatedtothefactthattheyhavehigherstoragecapacitiesandtheotheroneisthatstorageoperatesisothermallyatthemeltingpointofthematerial.

ThePHCcanbeeithersolidtoliquid,orliquidtogas.Water/icerepresentsthemosteffectivephasechangematerial.FromacostperspectiveitisquiteinterestingsinceisknowntobethecheapandalsothesimplestPCH.Unfortunately,thefreezingtemperatureofwaterisfixedat0°(32°F)whichmakesitinappropriateformostofenergystorageapplications(PCMProductsLtd,2016).

6.5.2.1 Ice storage air conditioning

Thermalenergystorageislikeabatteryforabuilding’sair-conditioningsystem.IceismadeandstoredinsideIceBankenergystoragetanksduringnighttimehours,whichrepresenttheoff-peakperiod.Afterthisprocess,thestorediceisusedtocoolthebuildingusersduringthefollowingday.

Thisprocessavoidsthehighenergycosts,alongwithpeakdemandchargesduringtheday.Theicestoragesystemprocesscomprehendstheicechargingmodeandicemelt/burnmode.Additionalsavingsaredeliveredfromextendedfreecoolingperiods.

Themainpurposeoficestorageistoshifton-peakelectricloadtooff-peaktimes,thisbringssignificantbenefitsintermsofreductionofairpollutingemissionsandthereforetoenvironmentandpeople’shealth(CALMAC,2016).

6.5.3 HeatStorageviaChemicalReactions

Theuseofheattocauseaspecificphysicochemicalreactionisanotherpossibilitywhenstoringthermalenergyandshouldbetakenintoconsideration.Theproductsthatresultfromthisprocesscanalsobestored.Whenthereversereactiontakesplacetheheatisthenreleased.Heatexchangeisconnectedtoaconstantleveloftemperatureduringthetimereactionoccurrences.Thetemperatureofheatreleaseandheatstorageatmosttimesaredifferent.Thermo-chemicalreactionscanbeusedindifferentways,forexampletocontrolhumidity,tostoreheatandcold,andalsoforthermalenergytransportationduetothehighstoragecapacity(IEA,2013b).



6.5.1 KPIsevaluationforheatstorage

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweentheheatstoragetechnologiesintroducedintheprevioussectionisproposed.Ithelpsgivingaclearandsimpleunderstandingofeachtechnologystrengthandweaknesstowardsalowcarbonfuture.

Themainsourcesthatinformthetablebelow,comefromCALMAC(2016),GENI(2012)andVV.AA.(2013c).

Table15:KPIsevaluationforheatstorage

Theme TypeofindicatorSensibleHeat

Storage

PhaseChange

Materials

Thermo-Chemical

Storage

Environmental

impact

Mainenvironmental

impactNegligible

Capital

investmentcost

Energy-relatedcost(€/kWh)

0.1-10 8-50 10-100

Performance

indexEfficiency 50-90% 75-90% 75-100%

Performance

index

StorageCapacity(kWh/t)

10-50 50-150 120-250

Technological

regime

Infrastructurelifespan

10-30(dependsonthenumberofstoragecycleandtemperature)

Technological

regime


Medium-High Medium-High Medium-High

Political

commitment




Publicopinion


technologyMedium Low-Medium Low

Ascanbeseenfromtheabovetable,heatstoragetechnologieshaveagenerallylowimpactontheenvironment.Themaindifferencebetweentheproposedtechnologygroupsliesinthecapitalcostsinvolved:sensibleheatstoragemethodsarelargelythecheapest,whilstPCMandthermo-chemicalstoragerequireshigherexpensesforequipmentpurchasingandinstallation.

Technicalperformancesaregenerallyhighforthesetechnologieswiththehighestvalues,whichcharacterisethethermo-chemicalstoragemethods(efficiencyupto100%).Also,despitethegoodperformancesand“green”aspectoftheseprocesses,theyarenotatfulltechnologicalmaturenesslimitingtheirabilitytobuildlargemarketshares,andpublicopinionisnotcompletelyacceptinginexploitingthesetechnologiesyet.Thereisnospecificpolicydedicatedtoheatstoragemeasures.



7 Energyendusers

Theenduserstageofthesupplychainisaverywidefield,whichcomprehendsmultipleaspectsoftheenergysystem.AsshowninFigure13,thethreemainsectorsresponsiblefortheEuropeanUnion’sfinalenergyconsumptionareHouseholds,TransportandIndustry.Inthissection,wearegoingtofocusmainlyonHouseholdsandTransport.Themaintypesoftechnologicalsolutionsforbuildingcomfort(lighting,heating,coolingandventilation),buildingcontrol(BuildingAutomationandControlSystems),individualpowerandheatgeneration(microCHP),alongwithprivatetransportwillbeinvestigated.

Figure13:Europeanfinalenergyconsumptionbysector(Eurostat,2015)

WiththeEuropeanEnergyRoadmap2050,energyefficiencyhasbecomekeytotheEU’sstrategicdevelopment.Moreefficientbuildingswillprovidebettercomfortfortheinhabitants,whilereducingenergydemandandresultincostsavingsandGHGemissionreductionsfrompowerplants.

In2015,buildingswereresponsiblefor40%ofenergyconsumptionand36%ofCO2emissionsintheEU.Thisismainlyduetothefactthatmostofthesebuildingsareoldandinefficient.TheEuropeanCommissionhasestimatedthat,currently,about35%oftheEU'sbuildingsareover50yearsold.Itisclear,then,thatalotofimprovementsstillneedtobedoneinsuchacriticalsector(EuropeanCommission,2016d).

EventhoughbuildingtechnologiespresentseveraldifferencesdependingontheregionofEuropeconsidered,itispossibletogiveageneraloverviewofthecurrentstateofthesectorbasedonwhenthebuildinghasbeenlastretrofitted.

Currentsituationforbuildingwithoutretrofittinginthelast10-15years:

• Lighting:MainlyFluorescentandCompactFluorescentLamps(CFL)areinstalledand,inresidentialbuildings,itisoftenpossibletofindolderincandescentlamps.Automationsystemsareveryrareandonlyimplementedincommercialbuildings.

• MicroCHP:MicroCHPsolutionsareimplementedveryrarely.

• Heating:Buildingaregenerallyheatedwithindividualgasoroilfiredboilers.AswehavealreadyalludedtoinChapter4,districtheatingwouldbeamoreefficientsolution,buthasbeenmainlyimplementedintheNorth-EastregionsofEurope.

• Ventilating:Buildingairqualityisguaranteedalmostsolelybynaturalventilation.

31.6%

26.8%

25.1%

13.8%

2.2%0.6%

EnergyconsumptionbysectorinEU

Transport

Householding

Industry

Services

AgricultureandforestryOther



• Airconditioning:Coolingsystemsarepresentmainlyincommercialbuildingsandrarelyinresidentialones.Thetechnologyinstalledisinthemajorityofcasesacentralchillerunit.

• Buildingmonitoring,automationandcontrolsystems:Indoorcomfortsensorsarerarelyinstalledandtemperaturesensorscanbefoundafewtimesincommercialbuildings.BuildingAutomationandControlSystems(BACS)arenotused.

Inthelast10yearsEuropehasstartedtopushtowardsanimprovementinbuildingefficiency,withpoliciesandincentivesthatsupportbuildingretrofittingoperations.Thelatestdirectivethatregulatesbuildingefficiency,inordertoreachtheRoadmap2050targets,isthe2012/27/EU,whichdefinesaseriesofcommonmeasuresforenergyefficiencypromotionacrosstheEU.Followingthedirectiveguidelines,moreadvancedtechnologiesareimplementedinmodernorrecentlyretrofittedbuildings,especiallyconcerningmonitoringandcontrol.

Thecurrentsituationforneworrecentlyretrofittedbuildingincludes:

• Lighting:LEDlampsarerapidlybecomingthestandard,astheircostreducesduetotheirlowelectricityconsumptionandhighqualityillumination.Lightcontrolsareoftenimplemented,inparticularincommercialbuildings,withapredominanceofVacancy/Occupancysensors.Residentialbuildingsstarttoseetheinstallationofcontrolsensorsaswell,inparticulardimmersforindoorlightingandtimersordaylightingforgardens.

• MicroCHP:MicroCHPsystemsarebecomingmorefrequent,allowinguserstosavemoneyonbothelectricityandheat,reduceGHGemissionsandsellexcesselectricitybacktothegrid.

• Heating:Theinstallationofheatpumpsismoreoftenpreferredovertraditionalboilers,duetothehigherefficiencyandlowerenvironmentalimpactprovided.

• Ventilating:Mechanicalventilationisoftenpresent,sinceitcanguaranteehigherlevelsofindoorairquality.

• Airconditioning:VRVareoftenimplemented.Theirchoiceoverchillersishighlyprojectdependent,butduetomorecompactdimensionsandmodularitytheyarebettersuitedforretrofittingoperationswherespaceisanissue.

• Buildingmonitoring,automationandcontrolsystems:TemperatureandHumiditysensorsareoftenpresenttoregulatemechanicalventilation.CO2sensorsareapossibilitybuttheyarelessfrequentlyinstalled.BACSareoftenusedincommercialbuildings.

Transportismoreresilientthanthebuildingsectortochangesanditisstilldominatedbygasolineanddieselcarsintheprivatesector.Inrecentyears,however,wehaveseenastrongincreaseinthenumberofelectriccarssoldinEurope.AccordingtotheEuropeanAutomobileManufacturersAssociation,duringtheperiod2014–2015,electricalcarssawanincreaseofbetween50%and70%inunitssoldwhilehybridcarshaveincreasedtheirunitsalesbyaround20%,forecastinganincreasingimpactfromthoseemergingtechnologiesinthetransportsectorinthenearfuture.

Electrictransportisnotlimitedonlytoprivatecars,butplaysanimportantroleinpublictransportaswell(bus,tram,metro).WithincreasedurbanisationtakingplaceacrossEuropecitiesareevolvingtoprovideamoreefficientpublictransport,whichcanguaranteehighenergysavingsandabetterqualityoflifecomparedtoprivatetransportoptions.



7.1 LightingLightingisanessentialpartofeverydaylife,aslightingtechnologiescanbefoundineverysector,fromindustrytobuildingortransportationandwithdifferentaims,suchasindoorillumination,trafficlights,carslights,etc.

Inthefollowingsections,wefocusonenduserapplicationsincludingthemaintypeoflampspresentinthemarketandthemaincontrolsystemusedtoregulatetheirfunctioning.Thesavingsthereforeonenergyconsumptionwillalsobepresented.

7.1.1 Incandescentlamps

Incandescentlightingworksbyheat-drivenlightemissions(incandescence).Lightisproducedwhenafilamentoftungstenisheatedbyanelectriccurrentuntilitglows.

Withconventionalincandescentbulbs,thefilamentisprotectedfromcomingincontactwithoxygenintheairthankstothelampbulb,preventingthefilamentfromburningup.In2014,79%oflampsaleswereincandescentlamps.Eventhoughtheyarecharacterisedbyalowefficacy(around8to14lm/W),mostoftheselampscanmanagetoconvertintovisiblelightnomorethanthe8%oftheenergytheyuse,wastingtheremaining92%asheatlostintheenvironment.Incandescentlampsarecheap,simpleinoperation,aredimmableandemitagoodnaturalcolourlight,buttheirworkinglifeisshort(typicallybetween400-2,000hours)whencomparedtoother,morerecent,technologies.Overall,theyaretheleastefficientlightsourceswithenergyratingsofE,ForG.

UndertheEcodesignDirective,between2009and2016,traditionalincandescentbulbswillceasetobesold(withtheexceptionofsomespecificapplications)andwillgraduallybereplacedbyothertypesofelectriclight.Incandescentbulbsmainapplicationisfordomesticanddisplaylighting,butcanalsobeusedforcommerciallighting.Oneoftheirdrawbacks,poorenergyefficiencyandheatwasting,canbecomeanadvantageinapplicationssuchasincubators,egghatching,heatlampsforreptilesandforsomeindustrialheatinganddryingprocesses(Tahiretal.,2014:9).

7.1.2 Halogen

Inhalogenlamps,thefilamentoftungstenissealedintoacompacttransparentenvelopefilledwithaninerthalogengas.Thankstothisprocess,thelifetimespanofthebulbishighlyincreased.Itoperatesitsfilamentatahighertemperatureandhasslightlyhigherefficacyof10–25lm/Wwhencomparedtoincandescentlamps,leadingtosavingpossibilitiesofupto50%.Anotheradvantageofhalogensisthattheyhavethepossibilitytobedimmed.HalogenlampsareusuallyenergyratedatBorCandhavealongerlifethanastandardincandescentbulb.However,consideringtheincreasingdemandforhighlevelsofefficiency,comingfrombothlegislationsandcustomers,halogenlampsarestillconsideredapoorsolutionintermsofefficacyandhavearelativelyshortlifetimeswhencomparedtoothersolutionssuchasCompactFluorescentLightbulbsandLightEmittingDiodes(LEDs).

Halogenlampsofferagoodqualitylightandcanproduceacolourintherangeof2,700to3,200Kwhichisarelativelycomfortable,warmwhitelight.Thismakethemidealforhomeinstallationsandstudios,oringeneralallthoseplaceswhereabrightwarminstantlightisrequired.Halogenlampsareoftenusedincars,floodlights,desktoplamps,projectorlampstobeusedintheatresorstudios(Tahiretal.,2014:9).

7.1.3 CompactFluorescentLamps(CFL)

CFLsuselesspowertosupplythesameamountoflightasanincandescentlamp,withtypicallyefficacyofbetween50to70lm/W,andtheycanachieve75%savingswhencomparedtoconventionallightbulbs.Ithastobenoted,though,thatCFLscontainmercury,ahighlytoxicandpollutingmaterial.Forthisreason,CFLsattheendoftheirlifecyclehavetobedisposedofsafely,inaccordancetothestrictEUregulations.In



recentyears,withtheincreasingdemandofhighlyefficientlamps,theuseofCFLshavebeenencouragedbymultipleorganisationsthroughouttheworld,undertakingseveralmeasurestoencouragetheiradoption,giventheirabilitytoreduceelectricityconsumption.

CFLsrepresentasimpleandquicksolutionforhouseholdsandbusinessestoincreasetheirenergyefficiency.Moreover,CFLshavetheimportantadvantageofaveryfastreachoftheirfullbrightness,unlikeincandescentlampsthatneedsometimeto'warmup'.Ontheotherside,notallCFLsaresuitablefordimming,sotheyshouldbeselectedwithcare,dependingonthespecificneeds.GiventhesimplicityandflexibilityofCFLs,someelectricutilitiesandlocalgovernmentshaveeithersubsidisedCFLsorprovidedthemfreetocustomersasafastandeffectivemeansofreducingelectricitydemand.ThemajorityofCFLapplicationsareinternalinplacessuchasofficesorcorridors(Tahiretal.,2014:11).

7.1.4 LED

LEDlampsarebasedondiodes,atechnologythatispresentinmanyelectricaldevicessuchascomputers.Theyemitlightwhenelectricityispassedthroughachemicalcompound(crystal),exitingittogeneratelight.LEDlampsareusuallymadeofaclusterofLEDspackedinasuitablebulbandcanofferawhitelightofupto250lm/W.Lifespansaregreatlyincreasedwithrespecttoolderlamptechnologies,witharound50,000hours(someLEDsevenpromise100,000hours)ofworkinglife.LEDtechnologyoffershighefficacy,ultra-longlife,andlimitedenvironmentalimpact,usingonly10%ofthepowerrequiredtogeneratethesameamountoflightwithstandardincandescentbulbs.Asacomparison,itisworthnoticinghowCFLlampsuse20%ofincandescentlampenergyandhalogenlampuse70%.

LEDsareatypeofSolidStateLighting(SSL),whichmeanstheyusedifferenttypesofsemiconductorLEDsassourcesofillumination.BeingbasedonSSL,LEDscanbeeasilyandsmartlycontrolledandprogrammed,makingthemthebestlightsystemchoicewhenahighdegreeofcontrolisrequired.ThishighversatilityallowsLEDstobeusedinaverywiderangeofapplications,frominternallightingtotrafficandstreetlighting,fromverysmallportablelampstobigscaleADsscreens.

SomeofthedrawbackswithLEDSincludetheinitialcost,theuniformityoflightoutputandlackofextensivedatafrommanufacturers,duetotherelativelynoveltyofthetechnology.Asthedevelopmentinthisareacontinues,itisexpectedthattheseissueswillbeovercome(Tahiretal.,2014:14).

TwocompetingtechnologieswhichcouldradicallychangethenatureoflightinginthefutureareOrganicLightEmittingandPolymerLightEmittingDiodes.

• Organiclightemittingdiode(OLED):OLEDsaremadebyplacingaseriesoforganicthinfilmsbetweentwoconductors.Theymakeuseofflatdisplaytechnologyandwhenelectricalcurrentpassthroughit,abrightlightisemitted.Duetothenatureofthistechnology,OLEDsareintrinsicallywellsuitedforindoorilluminationandcouldopenthewaytonewsolutionsthatabandontheuseofluminaries,suchasglowingwallpapersorilluminatedceilingtiles.OLEDsarealreadyonthemarketfordisplaysapplications,suchasTVsorportabledevices(smartphones,tablets,laptops,etc.).

• Polymerlightemittingdiode(PLED):PLEDsconsistofthin,flexiblefilmmadeofpolymersandcapableofemittingthefullcolourspectrumoflight.PLEDsareagoodexampleof'nanotechnology'.Theabilitytodissolvetheactivematerialsinasolventtoforman"ink",anddepositbyarangeofprintingtechniquesonawidevarietyofsubstratesatlowtemperaturesprovidesanumberofmanufacturingadvantagesoversmallmoleculeOLEDtechnology.ThetotalthicknessofalllayersinaPLEDdisplaydevicecanbelessthan500nmcomparedtoahumanhairwhichis0.1mmthick.



7.1.5 KPIsevaluationforlightingtechnologies

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthelightingtechnologiesintroducedintheprevioussectionarepresented.Takingintoaccountthefastpaceatwhichthisspecificmarketischanginginrecentyears,witharapidgrowthofLEDlampsinthemarket,theproposedtablehelpsgivingaclearandsimpleunderstandingofeachtechnology’sstrengthandweakness.

ThemainsourcesthatinformTable16,below,comefromTahiretal.(2014),NavigantConsultingInc.(2012a)andNavigantConsultingInc.(2012b).

Table16:KPIsevaluationforlightingtechnologies

Theme Typeofindicator Incandescent Halogen CFL LED

Environmental

impact

Presenceoftoxicmaterialrequiringdisposal No No Yes Yes

Performance

index

EnergyUse(MJ/20millionlumen-hrs) 15,100 13,000 3,780

3,540-1,630

Capital

investmentcostAveragepurchaseprice* €0.40 €1.50 €1 €5-30

Technological

regimeLifetime(hours) 750-2,000

3,000-4,000

8,000-10,000

25,000-50,000

Technological

regimeMaturityoftechnology High High High

Medium-High

Political

commitmentPolicysupport Banned

Plannedban

Accepted Accepted

Publicopinion Marketshare(2011) 69.3% 4.9% 25.4% 0.4%**

*CostComparisonfor60-wattincandescentequivalentlightbulb.

**Officialdataforalltechnologieshasbeenfoundfor2011,butLEDmarketshareisrapidlygrowing(Yu,2015).

Themostmaturelightingtechnologyisrepresentedbyincandescentlamps.Asshownintheprevioustable,theyhavethehighestenergyabsorptionindexwhencomparedtotheotherproposedlightingtools.Forthisreason,althoughtheystillrepresentthemostdiffusedlightingmethodtheyarenowgenerallynolongersoldintheEUmarket.

Referringtothemostefficientandinnovativesolutions,CFLshaveamorematuretechnologicalbackgroundthanLEDs,andthisisclearlyreflectedinthehighermarketsharecoveredbythistechnology.

Ontheotherhand,LEDshaveevenhigherefficiencieswhencomparedtoCFLs,butsincetheyareanemergingtechnologytheirmarketpricesarestilltoohightoincreasetheirmarketshare.Moreover,fromatechnicalpointofview,it’snoteasyregulatingLEDs’intensity,becausenotalltypesofLEDcanbeinterfacedtolightcontrolsystems,whicharedescribedindetailinthefollowingsection.Generally,LEDstechnologyisdevelopingstronglyandtheircostsarebecomingmoreacceptableforthegeneralpublic.Itcanbeeasilyforeseenthattheywillestablishgreaterandgreatermarketshareinthenearfuture.



7.1.6 Lightingcontrolsystems

Lightingcontrolsystemsaretechnologiesthatpermittocontrolthefunctioningoflampsindifferentways,suchasregulatingthelightintensityorsimplycontrollingtheON/OFFfunctionalityinmanualorsmartways.Inthenextsections,themainlightingcontroltechnologiesusednowadaysarepresented(Eaton,2014).

7.1.6.1 Switches

Switchesarethemostcommontypeoflightingcontrolusedinbuildings.Theyaresimpletoinstallandoperate,arerelativelycosteffectiveandcanworkwithalltypeoflightinglampswithoutanyproblem.Theymakealsopossibletocontrolmultipleluminarieswithonesingleswitch.

Ifoperatedcorrectly,switchesallowuserstohaveanefficientenergyconsumption,butmostofthetimesthisisnotthecase.Userstendoftentoforgetlightsonwhenleavingaroom,especiallyincommunalareas,causingimportantenergywaste.

Overall,thesystemissimpleandreliable,butprovidenoautomationnoradvancedcontrolonthelighting.

7.1.6.2 Dimmers

Dimmersarethemostcommonlyusedtypeoflightingcontrolsysteminresidentialbuildings,afterswitches.Theyallowtheusertocontrolthelightintensitymanually,makingitpossibletoreduceenergyconsumption,easilycuttingbackanyunwantedover-lighting.Eventhoughtheycanprovidesomeenergysavings,themainreasonhomeownersusuallychoosethissolutioniscomfort,thankstothepossibilitytodimlightingfollowingtheuserpersonalneeds.

DimmersarenotcompatiblewithsometypesofCFLandLEDlamps,andsomelampsmaycausemoreenergytobeconsumedandthelamplifemaybeshortenedcomparedtoasimpleon/offswitch.

7.1.6.3 Photosensors

Photosensorsarebasedonalight-sensitivephotocellthatproducesanelectricalcurrentproportionaltotheamountofexternallightingmeasured.Inthisway,photosensorsareabletodimlightintensitybasedonhowmuchnaturallightisalreadypresentintheroom,inordertomaintaintherequiredtotalamountofillumination.Thesecansolvetheproblemofover-lightingbecausetheycanreduceartificiallightwhenthereisadequateandsuitablenaturallightpresent.

Theyaremainlyusedincommercialbuildings,whereworkingactivityisperformedduringdailyhoursandthistypeofcontrolcanhaveahighimpactonenergysavings;whileinresidentialbuildingstheirmainapplicationistosimplyturnonandoffexternallightingwhenneeded.

Photosensorareanefficientandreliablewaytoreduceenergyconsumption,buttheyrequiretheinstallationoflampsthatcanbedimmed.Thepossibilityofwirelesstechnologyincreasestheflexibilityandpossibilityforretrofittingofthissolution.

7.1.6.4 Occupancy/Vacancy sensors

Occupancy/vacancysensorsautomaticallyturnonorofflightingwhensomebodyentersorleavesaroom,therebyincreasingenergyefficiency.Differenttechnologiesareusedtodetectthepresenceofapersoninsidetheroom,suchaspassiveinfrared,ultrasonicandacoustic.Mostofthecommerciallyavailablesolutionsimplementmorethanonetechnologyatthesametime.

Thedifferencebetweenoccupancyandvacancysensorsissimplythatthefirstoneautomaticallyturnsthelightsonwhensomeoneenterstheroom,whilethesecondoneonlyturnsoffthelightiftheroomisleftemptyforacertainamountoftime.Inresidentialbuildingsvacancysensorsareusuallypreferred,since



theycansavemoreenergy,duetothefactthathomeownersdonotalwaysneedtoturnonthelightswhentheyenteraroom.

Whileprovidinganautomaticsolutionforlighting,withhighpossibilitiesofenergysavings,thiscontroltechnologydoesnotsolvetheproblemofover-lighting.Anotherimportantissuewithoccupancysensorsistheirneedtobewelltunedinordertoavoidgeneratingfrustrationintheusers.Theexperienceofanautomaticlightturningoffwhenusingatoiletisacommonatypicalexampleofafrustratingoccupancysensorfailure.

Thepossibilityofwirelesstechnologyincreasestheflexibilityandpossibilityforretrofittingofthissolution.

7.1.6.5 Timers

Timersareanefficientwayofreducingenergyconsumptionastheyallowuserstoregulatethelightingdependingontheparticulartimeofthedaytheyneedit.Theycomeintwovarieties,countdownandastronomical.Countdowntimersallowtheusertoturnonthelightsataparticulartimeandforacertainperiodduringtheday.Astronomicaltimersarebasedonsunsetandsunrisetime,automaticallycalculatedeverydaydependingontheuser’sgeographicalposition.

Theycanberegulatedtoworkinawaysimilartophotosensors,varyingtheleveloflighttosuitdailytasksatdifferenttimesoftheday.Theymayalsobeusedtochangethelightingcontrolregimepassing,forexample,frommanualswitchingduringthedaytoautomaticmovementsensorsatnight.

Timerspresentanautomaticsolution,butneedtobecorrectlyprogrammed,followingtheuser’sneedsandhabits,inordertoachievehighenergysavings.Thedrawbackwiththiscontroltechnologyisthatitdoesn’ttakeintoaccountthepossibledailyvariabilityandcannotautomaticallytunethedifferentlightintensityneededbetweenasunnyandacloudyday.

7.1.7 KPIsevaluationforLightingcontrolsystems

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthelightingcontrolsystemsintroducedintheprevioussectionareexplored.Duetotheveryspecificnatureofthediscussedtechnologies,theKPIsconsideredforthefinalanalysisinthefollowingtableareverycasespecific,puttingmorefocusonatechnologicalcomparison.ThemainsourcesthatinformTable17,below,comefromEaton(2016).

Table17:KPIsevaluationforlightingcontrolsystems

ThemeTypeof

indicator

Simple

switchDimmers Daylighting

Occupancy

sensorsTimers

Capital

investment

cost

Averagemarketprice

1-3€ 20€ 25-30€ 25-30€ 25-30€

Capital

investment

cost

Averageannualenergy

savings*- 38% 26% 50% 54%

Technological

regimeOperation Manual Manual Automatic Automatic

Semi-automatic



ThemeTypeof

indicator

Simple

switchDimmers Daylighting

Occupancy

sensorsTimers

Technological

regimeControl ON/OFF

Intensityregulation

Intensityregulation

ON/OFFIntensityregulation

Technological

regime


High High High High High

Technology

flexibility

Fieldofapplication

Residential

building

Residential

building

Commercialbuilding

Commercialbuilding

Commercialbuilding

Political

commitment

AvailableGrants&

PolicysupportEuropeanDirective2012/27EUonEnergyefficiency

Publicopinion

Degreeofacceptance

andsuccessofthetechnology

-Medium-High

Low-Medium Medium Medium

*valueconsideredforincandescentlamps.Usingmoreadvancedlampsthosevaluesdecrease.

Aswecanseefromtheabovetable,itmustbefirstlypointedoutthatnotallthebuildingtypologiesareequippedwiththesamelightcontrolsystems.Indeed,themostoftheresidentialbuildingshavenocontrolsystems,ormanualdimmersforsinglelampsinstalledintheapartments.Veryoften,commercialandindustrialbuildingshavemorecomplexandefficientcontrols,inordertominimiseenergyconsumptionandcosts.Generally,lightingcontrolsystemsarenotlargelyused,becausepeoplearestillmainlyfocusedonthefinallightingtool(i.e.,thelamp)absorption,ratherthaninvestingmoneyintoanefficiencyinterventionatsystemlevel.

Notonlypublicopinion,butalsopoliticalcommitmentplaysanimportantroleinthis“misrecognition”oflightingcontrolsystemsimportance:infact,ifenergyefficientlamps(LEDs)utilisationisencouragedwitheconomicincentivesanddiscounts,noactionsareactuallytakeninordertoboostthediffusionoflightingcontrolsystemsotherthanpoliciesinfavouroftheoverallbuildingefficiency.

Asshownintable15,investmentcostsforthepresentedtechnologiesarealmostthesame(exceptforthesimplestswitchtool).Then,thechoiceofthebesttechnologyisnotmoneydriven,buteachmethodisoftenselectedonthebasisofaspecificapplication.Manualdimmersaremainlychosenforresidentialhouselightingsystems;daylightingcontrolisthemostsuitableforresidentialoutdoorareasorworkingbuildings;systemsbasedonoccupancyorvacancysensorscanbeusedincommercialbuildings,inordertolighttheroomsuponlyifneeded(i.e.,ifpeoplearepresentintheroom);timerscanbeusedincommercialorindustrialbuildingstoo,especiallyintransitzones.

7.2 MicroCHPUsingthesameprincipledescribedforcogenerationdistrictheating,microheatandpowersystemsallowfortheproductionofbothheatingandelectricityonasmallerscale(0,3-50kW),idealforsingle/multi



familyhomeorsmallofficebuilding.Animportantadvantageoflocalgenerationisthatitlackstheenergylossesofenergytransportationoverlongdistances,inparticularforheat.MostmicroCHPunitsoperateingrid-parallelmode,sothatthebuildingcontinuestoreceivesomeofitselectricalneedsfromtheelectricalnetwork,butitmayalsoexportsomeelectricitytotheelectricalnetwork.

Althoughthetotal"efficiency"ofamicroCHPsystemissimilartoaboilersystem,theelectricityproducedhasamuchhighervaluethanheat.ItisthevalueofthiselectricitywhichcoverstheinvestmentcostofthemicroCHPunitandprovidesanetsaving.

Inthefollowingsections,themainsolutionsformicroCHPareintroducedanddiscussed(VV.AA.,2006).

7.2.1 Reciprocatingengines

Reciprocatingenginesgeneratemechanicalpowerbyusingtheenergyproducedexpandingagasburnedwithinachamberintegratedtotheengine.Forthisreason,reciprocatingenginesarealsocalledinternalcombustionenginesorendothermicenginesandtheyarethetypeofenginecommonlyusedincars.

WhenusedforCHPgeneration,theenginedrivesanelectricgeneratorwhiletheheatfromtheengineexhaustgasesisusedforbuildingheatingpurposes.Engineshavetheadvantageofprovidinghighefficiencieseveninsmallsizes,withtheadditionofmodularity.Forthisreason,theyarewidelyusedinsmallplantsand,dependingontheapplicationandamountofenergyneeded,severalsmallmodulescanbeassembledinonesystem.Modularityallowsforeasierandmoreefficientcontrol,inordertobetterfollowtheloadcurves,anditalsoeasesmaintenance.

Reciprocatingenginescanbespiltintotwomaincategories:

• Dieselengines:Theyarealsocalledcompression-ignitionengines,sincecombustionofthefuelisinducedfromthehightemperatureofcompressedair.Thiskindofenginepresentsahigherpowertoheatratiocomparedtosparkignitionengines,andoperatesthroughalargescaleofverysmallsizesfrom5!"#$ forsmallunitstoapowerequivalentofsome10%"#$ forlargesystems.Biodieselandrapeoilarepotentiallydiscreditedalternativesasfuelfordieselengines,inordertoreduce&'(emissionsandmaintainrelativelyhighefficiency.

• Sparkignitionengines:ThistypeofengineworkssimilartotheDieselengine,butignitionisprovokedthroughanelectricalspark.Thistypeofenginerangesfrombetween3!"#$ and6%"#$ capacities.Theheattopowerratioislowerthantheoneachievablewithcompressionengine,yettheoverallefficiencyofthistechnologyishigher.

7.2.2 Microturbines

MicroturbinesareatypeofInternalCombustionEnginedesignedtoworkonarelativelysmallscalethatproducesbothheatandelectricity.Presently,microturbinescangeneratebetween25kWto1000kWforsmallscaleusage(residential,smallbuildings),withalmostthesameefficiencythanreciprocatingenginesatloweremissionlevelsof)'*andCO2.Microturbineshighoutlettemperature(>500°C),makethemsuitablefornumeroushighvalueapplications,suchasdirectdryingorheatingprocessesaswellascoolingapplicationsinabsorptionsystems.

Theyofferseveraladvantagescomparedtoothersmall-scalepowergenerationtechnologies.Thesmallnumberofmovingpartsmakeiteasytorepair,whilecompactsizeandlightweightsimplifytheinstallationofnewdevices.Microturbinesalsohavehighefficiency,feweremissionsandlowerelectricitycoststhaninternalcombustionenginesandtheycanusedifferenttypesoffuels,fromnaturalgastobiogasorwastefuels.



Thedrawbacksareahighinitialinvestmentcost,thelossofpowerandefficiencywithhighambienttemperatureoraltitudeandtheproductionofconstantnoise,whichcanbeproblematicinresidentialbuildings.Moreover,othersolutionsthatuserenewablesources,suchasPV,mayprovemoreattractive.

7.2.3 Stirlingengines

AStirlingengineisaclosed-cycleregenerativeheatenginewithapermanentlygaseousworkingfluid.Theyoperatebycyclicallycompressingandexpandingtheworkingfluid(generallyheliumorhydrogen),thankstothetemperaturedifferenceacrosstheengine.Theworkingfluidmovesasystemofpistons,resultinginaconversionofheatenergytomechanicalwork.Theexternalcombustionfacilitatesthecontroloftheprocessandsupportsacleanerandmoreefficientprocess.

Figure14:StirlingengineschematicviewinAlpha,BetaandGammaconfigurations

(diystirlingengine.com,n.d.)

ThemainadvantageofStirlingenginesisthat,thankstotheexternalcombustion,theycanmakeuseofalmostanyheatsourceandthusworkoptimallyinconjunctionwithrenewablesources.Theyalsoguaranteehighthermodynamicefficiencyandpresentalowlevelofnoiseandvibration(EnergyInternational,2002).Anotherpointtoconsideristhattheyhavealowpower-to-weightratio,makingitsuitableforinstallationswhereweightandspaceisnotanissue.

7.2.4 Fuelcells

Afuelcellproduceselectricityconvertingthechemicalenergyfromafuel(usuallynaturalgas)intoelectricitythroughachemicalreactionofpositivelychargedhydrogenionsandoxygenoranotheroxidisingagent.Eventhoughtheymaylooksimilar,theydifferfrombatteriesastheyrequireacontinuoussourceoffuelandoxygen,orair,tosustainthechemicalreaction.

Asfuelcellscreateelectricitychemically,ratherthanbycombustion,theyarenotsubjecttothethermodynamiclawsthatlimitaconventionalpowerplant,resultinginamoreefficientextractionofenergyfromafuel.Consequently,theycanprovideanelectricalefficiencyofaround40-50%(Jothilingam&Suresh,2015)beingaround10percentagepointshigherthancorrespondingengines.Wasteheatfromtheprocessisthenusedforheatingpurposes.



Thedownsideissignificantlyhigherinvestmentcosts,whicharemuchhigherthanreciprocatingenginesThesecostsneedtobeconsistentlyreducedinordertoimprovefuelcellsmarketacceptanceandmakethemaviablesolutionformicroCHPsystem.

7.2.5 KPIsevaluationformicroCHPtechnologies

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthemicroCHPtechnologiesintroducedintheprevioussectionisoutlined.Itgivesaclearandsimplepresentationofeachtechnology’sstrengthsandweaknesseswhenframedwithinalowcarbonfuturecontext.

ThemainsourcesthatinformTable18,below,comefromIEA(2015),VV.AA.(2010)andThimsen(2002).

Table18:KPIsevaluationformicroCHPtechnologies

ThemeTypeof

indicatorReciprocating

enginesStirlingengines

Micro

turbinesFuelcells

Environmental

impact

GHGemissions(gCO2/kWh) 600-690

Dependsontheheatsource

630 480

Performance

indexTotalefficiency 65-90% 65-95% 65-90% 85-95%

Performance

index

Electricalefficiency

25-45% 25% 15-30% 35-50%

Capital

investmentcost

Initialinvestment(€/!"#$)

340-2000 2500-4500 900-25008.000-18.000

Technological

regimeLifetime(hours) 35.000 50.000 40.000 60.000

Technological

regime


High Medium HighLow-

Medium

Political

commitmentPolicysupport EuropeanDirective2012/27EUonEnergyefficiency

Publicopinion

Degreeofacceptanceandsuccessofthetechnology

Medium Low-MediumLow-

MediumLow-

medium

ThemostdiffusedCHPmethodisrepresentedbyreciprocatingengines,becauseoftheirlowcapitalinvestmentcosts,whencomparedtotheothersshown.Themainadvantageofmicroturbinesistheirlowerenvironmentalimpact,sincetheirpollutingemissionsarereduced,andtheirgoodenergyefficiency.Moreover,theirlifetimeismuchhigherthanreciprocatingengines.



Stirlingenginesarebecomingincreasinglysuccessfulinthelastperiod,thankstotheirquitehighflexibilityandthepossibilitytoadaptthemtothegrowingoutputfromrenewableenergysources,indicatingtheirsomewhat“green”credentialsinmicroCHPtechnology.

ThemostinnovativemicroCHPsolutionarethefuelcells.However,pricesarestilltoohighforthemtooccupyalargemarketshare.TheystillarethemostpromisingCHPmethod,havingthebestelectricalperformancesandthelongestlifetime.

NospecificpolicyisdedicatedtomicroCHPsolutionsatEuropeanlevel,theirimplementationfallsundertheRoadmap2050improvementmeasuresandeachmemberstateisfreetodirectitsevolutionandpoliciesonitsown.

7.3 BuildingheatingBuildingheatingisafundamentalcomfortinresidentialbuildingandworkplaces,whichmakesupforabigpercentageofthefinalusersutilitybills.Forthisreason,movingtowardsenergyefficientandeconomicsolutionsforbuildingheatingisaprimaryconcernnotonlyforenvironmentalissues,butalsoforeconomicalaspects.Severaltechnologiesarepresentednowadaysbut,especiallyforresidentialbuilding,aneffectivetechnologicalupgradeisstillfartotakeplace.

Inthefollowingsections,maintraditionalandinnovativebuildingheatingtechnologiesarepresented.

7.3.1 Boilers

Boilersareusedinbuildingheatingandindustrialprocessestogeneratesteamorhotwaterandcanbefiredbynaturalgas,fueloil,orcoal.Acentralheatingunitprovidesheattothewholefacilityanditissizedtomatchthesizeofthefacility.Anoversizedboilerwillresultinexcessivefuelconsumption,withrelativelyhighcostsandpollution,while,anundersizedboilermaynotbeabletogeneratethecorrectcomforttemperatureineverypartofthebuilding.

Theidealsizeforaboilerisonethatcanprovidejusttheneededamountofheatonthecoldestdayoftheyear.Sinceinthepasttherewasthetendencytoover-calculateboilersdimensions,inordertoleavesomesafetymarginincaseofaparticularlycoldperiod,mostboilersareoversizedbyatleast30%(Odesie,n.a.).

Thisideahaschangedtodayandtheemphasisisnowputonenergyconservation.Thisfact,togetherwithimportantimprovementsinheatlosscalculationsaccuracy,meansthereisnoneedtooversize.Thisallowssmallerradiatorsandlesswaterinthesystem,whichresultsinasmallerboiler,reducedfuelandinstallationcostsandreducedpollutingemissions.

Onaverage,boilershavecombustionefficienciesbetween78%and86%.

7.3.1.1 Fire-tube steel boilers

Thename"fire-tube"isverydescriptiveofthetechnology.Thefire,whichmeanshotfluegasesfromtheburner,passesthroughtubesthataresurroundedbythefluidtobeheated,which,inmostcases,iswater.Heatedwaterwillthenbecirculatedthroughallthebuildingforheatingpurposesorconvertedtosteamforindustrialuse.Thebodyoftheboilerwhichcontainsthefluidiscalledpressurevessel(Odesie,n.a.).

Typically,fire-tubeboilersdonotexceed25millionBtu/hr(MMBtu/hr),butcapacitiesupto70MMBtu/hrareavailable(EnergyStar,2015).

Theadvantagesofafire-tubeboilerareitssimpleconstruction,whichmakesitrelativelyinexpensive,availableincompactsizeandeasytorepair,andlessrigidwatertreatmentrequirements.

Thedisadvantagesaretheexcessiveweightinproportionwiththesteamgenerationcapacityandthepresenceofalargevolumeofwaterstoredinthepressurevessel.Inpractice,largevolumeofwatermeans



excessivetimerequiredtoraisesteampressureandaninabilitytorespondquicklytoloadchanges(P.C.McKenzieCompany,n.a.).

7.3.1.2 Water-tube steel boilers

Water-tubesteelboilersfunctionwithaworkingprinciplethatistheexactoppositeoffire-tubeboilers.Herethewatertobeheatedisinsidethetubesandcombustiongasespassaroundtheoutsideofthetubes.Thesetubesareconnectedtoasteamdrumandamuddrum.Thewaterisheatedandsteamisproducedintheupperdrum(Odesie,n.a.).Theavailablesizeforwater-tubeboilershaveawiderange:fromsmall,lowpressureunits(around10MMBtu/hr)tolarge,high-pressureunitswithsteamoutputsofabout300MMBtu/hr(EnergyStar,2015).

Theadvantagesofawater-tubeboilerarealowerunitweightinproportionwiththesteamgenerationcapacityandtheabsenceofalargestoredvolumeofwater.Thisallowsforlesstimerequiredtoraisesteampressure,agreaterflexibilityforrespondingtoloadchanges,andtheabilitytohandlehigherpressuresandtemperatures,andhighratesofsteamgeneration.Theyalsoareavailableinsizesfargreaterthanafire-tubedesign.

Disadvantagesincludeahighinitialcapitalcostandamorecomplexdesign,whichtranslatesintomoredifficultrepairandcleaningoperations.Moreover,incertaincases,physicalsizemaybeanissue(P.C.McKenzieCompany,n.a.).

7.3.1.3 Cast iron boilers

Castironboilersareusedinsmallinstallations(0.35to10MMBtu/hr)(EnergyStar,2016)wherethemostimportantrequirementislongservicelife.Aparticularfeatureoftheseboilersisthattheyarecomposedofprecastsections,meaningtheycanbemorereadilyfield-assembledthanwatertubeorfiretubeboilers.

Themostcommonproblemassociatedwithcast-ironboilersiscrackingduetooverheatingorthermalshock.Sincetheyaredesignedforsmallinstallations,atsimilarcapacities,cast-ironboilersaremoreexpensivethanfiretubeorwatertubeboilers.

7.3.1.4 Condensing boilers

Condensingboilersarethemostefficienttypeofboilersdevelopedtodate.Theyaremodernandhighlyefficientboilersthatuselessfueltoproducethesameamountofheat,thereforeresultinginlowerrunningcoststhanconventionalfire-tubeandwater-tubeboilers.Conventionalboilersexpelalotofwasteenergyashotvapouroutoftheirflu,whilecondensingboilersmakeuseofsuchheat,whichisdriventhroughtheboilerandusedtoprovideadditionalheatenergy.Thisismadepossibleusingtwoheatexchangersoralargerone,whichallowstherecoveryofusefulheatfromthewastegasesthatwouldbeotherwiselostthroughtheflue.Figure15showsaschematicviewofthisprocess.



Figure15:Condensingboilerscheme(microgreening.com,n.a.)

Sincewateriscondensedinsidetheboiler,fluegasisemittedintheairataconsiderablylowertemperaturethannon-condensingboilers.

Incommonfacilityheatingapplications,thecondensatewaterisatatmosphericpressureandisdrainedtoacentralcondensatereceiver,orintolocalsmallerreceiversthatpumpthecondensatebacktothecentralreceiverunit.

Theyaretypicallyfiredwithnaturalgasandoperatebetween95%and96%combustionefficiencies.Theyalsooperatemoreefficientlythannon-condensingboilersatpart-load.Condensingboilersareavailableincapacitiesbetween0.3and2MMBtu/hr(EnergyStar,2015),andcanbeconnectedinmodularinstallations.

Theadvantagesofcondensingboilersareagreaterefficiency(upto12%moreefficientthananon-condensingboiler),whichresultsinreducedrunningcostsand&'(emissions,andeasyinstallationandrepairoperations(Microgreening,n.a.).

Althoughcondenserboilersaremoreefficientthantraditionalboilersandwillthereforereducefuelbillsandcarbonemissions,theydostillrequireexpensivenon-renewablefuelsandproducegreenhousegases.

7.3.2 Furnaces

Furnacesareverysimilartoboilers.Themaindifferenceisthatafurnaceusesair,whileaboileruseswatertodistributeheatthroughoutyourhome.Inparticular,furnacesheatairthatisdistributedthroughoutthehouseviaablowermotorandthehome’sductsystem.Theycanbeusedforresidentialandsmallcommercialheatingsystems.Furnacesusenaturalgas,fueloil,andelectricityfortheheatsource.Naturalgasfurnacesareavailableincondensingandnon-condensingmodelsandtheycanprovidecoolingaswell.



Sincetheyworkmovingair,furnacesaremoresuitedforcoolingpurposes,whileadraftyenvironmentislesscomfortableforheating.Theyarelessexpensivethanboilers,butrequiremoremaintenance,requiringtochangetheairfilterevery1to4months,inordertohavegoodairquality(Fehr,2009).

7.3.3 Heatpumps

Heatpumpsaredevicesabletotransferheatfromasourceatlowertemperaturetoanotheroneathighertemperature,invertingthenaturalflowofheat.Thisprincipleissimilartoawaterpumpthatpumpswaterfromareservoirtoanotheronepositionedhigher(Robur,n.a.).Theheatpumpcycleisconstitutedoffourmainphases:

1) Therefrigerantfluidgoesfromgaseousstatetoliquidstateinthecondenser,transferringheattotheenvironment.

2) Intheexpansionvalvethefluidcooldown,partiallytransformingintovapour.

3) Intheevaporatortherefrigerantabsorbheatfromanexternalsourceandcompletelyevaporates.

4) Therefrigerantfluidatlowpressureisforcedintohighpressureincompressorandisheatedasaconsequence.

ThosefourphasesareshowninFigure16.

Figure16:Heatpumpcyclescheme

Aheatpumpisabletoreversethenormalheatingflowthankstoelectricconsumptiontogivepowertothecompressor.Theadvantageisthat,absorbingheatfromexternalenvironment(air,waterorground),itisabletogeneratemoreenergy(heat)thanitconsumes(electricity).Onaverage,aheatpumpcanproduce2.5kWhofenergyforany1kWhconsumed.

Theexternalmediumfromwhichheatisdrawniscalledacoldsource.Intheheatpumptherefrigerantabsorbsheatfromthecoldsourcebymeansoftheevaporator.

Themaincoldsourcesare(heatpumpcentre,n.a.):

• Air:typicallyairfromtheexternalenvironment,canbeheatedthankstoasolarcollector



• Water:whenavailable,waterfromriversandlakesnearbythefacilitytobeheated.Otherreservoirsmayconsistofwaterwhichhasbeenspecificallyaccumulatedandisusuallyheatedbysolarradiation.

• Ground:dedicatedspecificpipesaresunkintothegroundatvaryingdepths,usuallyfrom1to1.5meters.Groundhastheadvantagetomaintainamoreconstanttemperaturewithoutbeinginfluencedbyexternalweatherconditions.Thesepipesconstituteageothermalsystem.

Whilethelatestgascondensingboilersareultra-efficient,theydependuponfinitefossilfuels.Theheatprovidedbyaheatpumpistakendirectlyfromtheenvironment,andistherefore'green'.Iftheelectricityneededforthecompressortoworkisgeneratedfromrenewablesources,thenabuildingcanbeheatedentirelyrenewablyandcosteffectively.

Themaindisadvantagewithheatpumpisthattheyworkbestwhenthedifferencebetweenthecoldsourceandthebuildingtemperatureislow.Inparticular,theyarenotwellsuitedtobeusedinparticularlycoldenvironment.Heatpumpsarealsodifficulttoregulate(Robur,n.a.).

7.3.4 Solarheating

Solarheatingandcoolingcomprisesawiderangeoftechnologies,frommaturedomestichotwaterheaterstonewtechnologies,suchassolarthermallydrivencooling.Nowadays,themajorityofapplicationsforsolarthermalsystemsuserooftopglazedandunglazedcollectors.Thechoiceofsolarthermalcollectorgenerallydependsontheapplicationandtherequiredtemperature.Inthebuildingsector,non-concentratingflat-plateandevacuated-tubecollectorsaremostcommonlyusedforspaceandwaterheating.Theuseofsolarenergyforheatsupplyismostlylimitedtolowtemperaturesprocesses,suchashotwaterforsanitarianuse.Itshouldbenotedthatsolarthermalcombinationsystems,inwhichsolartechnologyiscombinedwithanauxiliaryheatingorcoolingsource,canbeusedtoincreaseheatingandcoolingefficiencyinbuildingsandtosupplythedemandthatisnotachievedbythesolarthermalsystem(IEA,2012d.).

7.3.5 Electricheaters

Electricheatingorresistanceheatingconvertselectricitydirectlytoheat.Electricheatisoftenmoreexpensivethanheatproducedbycombustionapplianceslikenaturalgas,propane,andoil.Electricresistanceheatcanbeprovidedbybaseboardheaters,spaceheaters,radiantheaters,furnaces,wallheaters,orthermalstoragesystems.

Electricheatersareusuallypartofafanoilwhichispartofacentralairconditioner.Theycirculateheatbyblowingairacrosstheheatingelementwhichissuppliedtothefurnacethroughreturnairducts.Blowersinelectricfurnacesmoveairoveronetofiveresistancecoilsorelementswhichareusuallyratedatfivekilowatts.Theheatingelementsactivateoneatatimetoavoidoverloadingtheelectricalsystem.Overheatingispreventedbyasafetyswitchcalledalimitcontrollerorlimitswitch.Thislimitcontrollermayshutthefurnaceoffiftheblowerfailsorifsomethingisblockingtheairflow.Theheatedairisthensentbackthroughthehomethroughsupplyducts.



7.3.6 KPIsevaluationforbuildingheating

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthebuildingheatingtechnologiesintroducedintheprevioussectionisproposed.Technologiesarecomparedathigherlevel,leavingadeeperinspectiontotheanalysisperformedintheprevioussections.Thetableprovidesasimpleandclearcomparisonbetweenthetechnologies,helpingthereadertoobtainaclearoverviewoftheheatingsolutionproposedinthisdeliverable.

ThemainsourcesthatinformTable19,below,comefromthesourcescitedintherelativesectionsabove.

Table19:KPIsevaluationforbuildingheatingtechnologies

Theme Typeofindicator Boilers Furnaces Heat

pumpsSolarheating

Electricheaters

GHGEmissions Fuelused Gas–Oil Gas–Oil Electricity Sunlight Electricity

Capital

investmentcost

Installationcost(€)

5.000-60.000

1.500–5.000

1.500–45.000

300–1.200(€/+()

200–1.000

Performance

indexCOP - - 3–4,5 - -

Technological

regime

Combustionefficiency

80-96% 80-96% - 30% 90%

Technological

regimeLifetime(years) 20-25 20-25 15 25 5-10

Technological

regimeMaturityoftechnology

High High HighMedium-High

High

Political

commitment

AvailableGrants&Policy

support

YESCondens.Boliers

η>93%

YESCondens.Furnaces

η>93%

YES

COP>4YES NO

Publicopinion

Degreeofacceptanceofthetechnology

High High HighMedium–

HighLow-

Medium

Boilersandfurnaces,themosttraditionalbuildingheatingtechnologies,generallyhavethelargestmarketshares.

Fromatechnicalpointofview,heatpumpscanworkwithhighenergyefficiencyperformances,especiallyinrelativelytemperateclimates.Inverycoldenvironmenttheirefficiencydecreases,andtheyneedaback-upboilerinordertowellwork.

Thelatesttechnologicalimprovementshavemadeboilersandfurnacesmoreefficient,andtheirenvironmentalimpactshavebeenmitigatedtoo,thankstoloweremissionsfromthecombustionprocess.

Solarheatingistheleastdiffusedtechnology,despiteitnotproducingGHGemissionsanditbeingtheleastharmfultotheenvironment.Therearetwomainreasonsfortheslowuptakeofsolarheatingtechnologies.



First,itisthemostrecenttechnologyandsoistheleastwellknown.Second,solartechnologiesingeneralhaveintrinsiclimitsconnectedtotheworkingintermittence,astheycanonlyworkduringtheday.

7.4 VentilatingInordertoguaranteeadequatecomforttotheinhabitants,removingstaleinteriorareandprovidingoxygenrecycle,theroleofbuildingventilationsystemsiscentral.Therehasbeenconsiderableconcernrecentlyabouthowmuchventilationisrequiredtomaintainthequalityofairinhomes.Toomuchventilationwillgenerateenergyefficiencyproblems,makingheatescapethebuildingduringcoldseasonsandenterduringhotseasons.Ontheotherside,alackofventilationwillresultinlackofoxygenrecycling,withadecreaseofinhabitantscomfort(Fehr,2009).

Whileopeningandclosingwindowsoffersonewaytocontroloutsideairforventilation,thisstrategyisrarelyusefulonaregular,year-roundbasis.Itbecomesnecessarytotakeintoaccountventilationneedsduringbuildingdesignprocess.Thefollowingsectionpresentsthemaintypeofintegratedbuildingventilationsolutions,eachonewiththeirprosandcons.

7.4.1 Naturalventilation

Naturalventilationistotheprocessofcirculatingairinanindoorspaceasaresultofpressuredifferencesarisingbetweentheinsideandtheoutsideofthebuilding,withoutmakinguseofmechanicalsystems.Twomaintypesofnaturalventilationcanbedefined:winddrivenventilationandbuoyancy-drivenventilation(NationalInstituteofBuildingScience,n.a.).Inwinddrivenventilationthedifferenceininsideandoutsideairpressureiscreatedbywindaroundthebuilding,whileinbuoyancy-drivenventilationit'stheresultsoftemperaturedifferencesbetweentheinteriorandexterior.Thewayairisenabledtocirculatethroughthebuildingissimplythankstopurpose-builtopenings,whichcanincludewindows,doors,solarchimneys,windtowersandtrickleventilators(Aereco,n,a.).

Inorderfornaturalventilationtobeeffective,caremustbetakenonclimate,buildingdesignandhumanbehaviour.Ifwellinstalledandmaintained,severaladvantagescanbeobtainedwhencomparedwithmechanicalventilationsystems.

Ingeneral,theadvantageofnaturalventilationisitsabilitytoprovideahighventilationrateatlowcost,thankstoaverysimpleandenergyefficientsystem.Itisanenvironmentalfriendlysolution,sinceitrequiresnoelectricityusageandaddnopollutinggasesintotheenvironment.Althoughtheair-changeratecanvarysignificantlydependingontheexternalweatherconditions,buildingscarefullydesignedtomaximisenaturalventilationbenefitsandproperlyoperatedcanachieveveryhighair-changeratesbynaturalforces.Manytimesnaturalventilationalonecanguaranteeorevenexceedtheminimumventilationrequirements.

Thereare,though,someimportantdrawbackstoanaturalventilationsystem.

Firstofall,naturalventilationisdependentonoutsideclimaticconditionsrelativetotheindoorenvironment,makingtheairflowratevariableandthereforedifficulttocontrol.Asaconsequence,airflowmaybeuncomfortablyhighinsomelocationsandstagnantinothersduringcertainunfavourableclimateconditions.Insomeareasitmaybeimportanttocontroltheairflowdirection,inordertoavoidcontaminationofadjacentcorridorsandrooms,andnaturalventilationcannotprovidetherequiredconsistentcontrol(VV.AA.,2009b).

Althoughthemaintenancecostofsimplenaturalventilationsystemscanbeverylow,ifanaturalventilationsystemisnotdesignedorinstalledproperlyormaintenancelevelislow,itsperformancecanbecompromised.Otherpossibledrawbacksthatneedtobeconsideredarethepossibilityofpollutedair



enteringthebuilding,presenceofnoiseduetothewind,insectvectorsandsecurityissues,duetothefactthatopenaccessareaintothebuildingmustbepresenttoletairflow.

Thesedifficultiescanbeovercome,forexample,byusingabetterdesignorhybridventilation.

7.4.2 Mechanicalventilation

Mechanicalventilationisusedforapplicationswherenaturalventilationisnotappropriate.Airflowisdrivenbyfans,whichcaneitherbeinstalleddirectlyinwindowsorwalls,orinstalledinairductsforsupplyingfreshairinto,orexhaustingairfrom,aroom.Beforeenteringinthebuilding,airisfilteredinordertoremoveparticulatesanddustfromtheair(Aereco,n.a.).

Mechanicalventilationcanbedividedinpositiveornegativepressureventilation.Inapositivepressuresystem,theroomisinpositivepressureandthepollutedairisleakedoutthroughanopening.Inanegativepressuresystem,theroomisinnegativepressure,andfreshairissuckedfromtheoutside.Abalancedmechanicalventilationsystemreferstothesystemwhereairsuppliesandexhaustshavebeenadjustedtomaintaineitheraslightlypositiveornegativepressureintheroom.Thisisachievedbysettingthesupplyandexhaustventilationatslightlydifferentrates.Amechanicalventilationsystemcanbecombinedwithallsortsofheatingandcoolingsystems.Acommonprocedureimplementedinordertoreduceelectricalconsumptionistheextractionofheatfromtheexhaustair,whichisusedtopreheatthefreshairsupply(heatrecovery).TheschemeisshowninFigure17.

Figure17:Mechanicalventilationwithheatrecoveryscheme(thegreenage.co.uk,2015)

Mechanicalventilationpresentssomeadvantageswithrespecttonaturalventilation.Itprovidesagoodcontroloftheventilationcapacity,independentfromtheoutsideweatherconditionsand,asmechanicalventilationcanbeintegratedeasilyintoair-conditioning,theindoorairtemperatureandhumiditycanalsobecontrolled(UOL-VENTILATION,n.a.).Controlispossiblealsoonairflowdirection,whichcanbeverycriticalinenvironmentsuchashospitals,andfiltrationsystemscanbeinstalledsothatharmfulmicroorganisms,particulates,gases,odoursandvapourscanberemoved(VV.AA.,2009b).Finally,mechanicalventilationcanworkeverywherewhenelectricityisavailable.

However,mechanicalventilationalsopresentssomecriticalproblems.Equipmentmaynotalwaysworkasexpected,andwhenafailureoccurs,normaloperationmayneedtobeinterruptedforthetimeneededforreparations.Ifthesystemservicesacriticalfacility,andthereisaneedforcontinuousoperation,alltheequipmentmayhavetobebackedup,whichcanbeexpensiveandunsustainable.

Installationandmaintenancecostsfortheoperationofamechanicalventilationsystemarehigherthanthoseneededfornaturalventilation,andmayconstituteaproblem,especiallyinprivatehouses(TheGreenAge,n.a.).



7.4.3 Hybridventilation

Hybridventilationistheidealsolutionwhentheenvironmentalandenergysavingbenefitsofnaturalventilationarerequired,butwhereforsomereasonsisnotpossibletoadoptafullypassivesystem.Thereasonsforthisimpossibilitymaybevarious,suchasabuildingsurroundedbytallerstructuresorsitedwherethereisunlikelytobesufficientwind.Inahybridsystemanintermittentfan,whichiscontrolledbyatemperaturesensor,pressurecontrollerorwindgauge,isactivatedwhentheairflowrateprovidedbynaturalventilationaloneisnotsufficient.

Hybridventilationhastheadvantagesofnaturalventilation,suchaseasymaintenance,low-energyuseand&'(emissions,combinedwiththeonesofmechanicalventilation,suchasreliability,flexibilityandincreasedcontrolpossibilities.Hybridventilationcanbringanimportantreductionofannualenergyuse,withanimportantpartofthisreductionduetoreducednightcoolingofthebuilding,whichisexcessivewithnaturalsolutionsonly.Nightventilationisenhancedbymechanicalsystems,whilenaturalsystemsarepreferredduringtheday.

However,thissystempresentssomedrawbacksaswellandneedstobeusedandimplementedwithcare.Thefansshouldbeinstalledeitheronawallortheroof,sothataircanbeexhausteddirectlytotheoutdoorenvironment.Thesizeandnumberofexhaustfansdependsonthetargetedventilationrate,andmustbemeasuredandtestedbeforeuse(Aereco,n.a.).

Problemsassociatedwiththeuseofexhaustfansincludeinstallationdifficulties(especiallyforlargefans),noise(particularlyfromhigh-powerfans),increasedordecreasedtemperatureintheroomandtherequirementfornon-stopelectricitysupply.

7.4.4 KPIsevaluationforventilatingsolutions

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthebuildingventilatingsolutionsintroducedintheprevioussectionisproposed.Thehighlevelcomparisonperformedintheprevioussectionbetweennatural,Mechanicalandhybridventilationisproposedagainhereinthetable.ItfollowsthattheKPIsaredescribedmainlybyqualitativeparameters.ThemainsourcesthatinformTable20,below,comefromAereco(n.a.).

Table20:KPIsevaluationforventilatingsolutions

Theme Typeofindicator Naturalventilation

Hybridventilation

Mechanicalventilation

Environmentalimpact Type NoneElectricity

consumptionElectricity

consumption

Environmentalimpact Level - Medium High

Capitalinvestmentcost Installationcost Low Medium High

Capitalinvestmentcost Savingsonheatlosses Low Low-Medium High

TechnologicalregimeVentilationflow

ControlLow Medium High

Technologicalregime Maturityoftechnology High High High



PoliticalcommitmentAvailableGrants&Policysupport

EuropeanDirective2012/27EUonEnergyefficiency

PublicopinionDegreeofacceptanceofthetechnology

High Medium–High Medium

Naturalventilationisthemostcommonlyimplemented,especiallyinolderbuildings.Itdoesnothaveanyimpactontheenvironmentsinceitdoesnotneedanyfuelorelectricity,butitprovidesaverylowcontrolonthe ventilation flow. For this reason, mechanical ventilation is growing in popularity and not only incommercialbuildings,sinceitallowsagreatercomforttotheusersthannaturalventilation.

Hybridventilationcomprehendsbothnaturalandmechanicalventilation. Itprovidesmorecontrolontheventilationflow,buttheopeningsinthebuildingnecessaryfornaturalventilationstillmakenotpossibletohavethelevelofcontrolofmechanicalventilation.Havingaconstantairexchangewiththeoutside,naturalandhybridventilationloseagainwhentakingintoaccountheatlosses.

7.5 AirconditioningAirconditioningsystemshaveanimportantroleincomfortcontrolofbuildinginhabitants,undertakingthesamefunctionofheatingtechnologies,butoppositeinheatexchangedirection.Itisworthnoting,though,howbuildingheatingisconsideredessentialandispresentinbasicallyallbuildings,whileairconditioningisstillviewedasaluxuryinmanyareasofEurope,especiallyforresidentialbuildings.Thesituationimproveswhenconsideringpublicbuildings(e.g.hospitals)orindustrialworkplacesandbuildingswithheavycomputerequipmentpresence(EuropeanCommission,2012a).WiththeraisingoftemperatureduringsummerinEuropeandtheincreasedconcernforenvironmentalissues,energyefficientairconditioningsystemmayseeahigherimplementationinbuildingdesignorduringretrofittingsolutionsinnextyears.

Thefollowingsectionpresentsthemainairconditioningtechnologiespresentonthemarkettoday.



7.5.1 Chillers

Inlargecommercialandinstitutionalbuildings,devicesusedtoproducecoolwaterarecalledchillers.Achillerisavapourcompressionmechanicalrefrigerationsystemthatcooldownthebuildingorprocesswaterextractingitsheatinadevicecalledevaporator.Astheheattransferbetweenthewarmwaterandthecoldrefrigeratortakesplace,therefrigeratorevaporates,changingitsstateintovapour,whilethewateriscooledandinsertedintotheprocess.Fromtheevaporator,therefrigerantmovesintothecompressor,whereitiscompressedinordertoraiseitstemperature.Whenthenowhigh-pressureandhigh-temperaturerefrigerantreachesthecondenser,itreleasesitsheat,returningtoliquidstate.Liquidrefrigerantpassesthroughanexpansionvalveandreturnstolow-pressurebeforeenteringagainintheevaporator(Miller,2010).Figure18giveaschematicviewofthisprocess.

Figure18:Chillerprocessschematicview(achrnews.com,2007)

Theheatexchangeinthecondensercanbeperformedthroughwaterorair.Thisdefinesthetwomaindifferenttypesofchillers(Miller,2010):

• Air-cooledchillers:Airisforcedthroughthecondenserwithamotorisedblower.Heatexchangeisincreasedusingagridofrefrigerantlines.Unlesswhenspeciallydesignedforhigh-ambientconditions,air-cooledchillersneedoutdoortemperaturesbelow35°Ctoworkefficiently.Theyareofferedonsmaller,packagedsystems(typicallyfromlessthanonetonto120tons).Theyareinitiallylesscostlythanwater-cooledcondensers,becausetheyrequirefewercomponentstooperate,butdonotallowthechillertooperateasefficiently.Air-cooledchillersEnergyEfficiencyRatio(EER)canusuallyrangefrom2.5to4.5.

• Water-cooledchillers:Theprincipleisthesameasair-cooledchillers,buttheyrequireonemoresteptocompleteheattransfer.First,thecondenserwaterabsorbstherefrigerantvaporheat,condensingit.Thenthenowwarmcondenserwaterispumpedtoacoolingtowerwherethe



processheatisfinallydischargedintotheenvironment.Thelowertemperatureachievedbyevaporatingwaterallowschillersservedbywater-cooledcondenserstooperatemoreefficiently.Thecondenseroperationcostsofacoolingtowerarelowerthantheonesneededtooperatetheelectricallydrivenfanusedonanair-cooledsystem.Moreover,whentheoutdoorairtemperatureissufficientlylowand/ortheairisverydry,thetemperatureofthecoolingtowerwatermaybelowenoughtodirectlycoolthechilledwaterloopwithoutuseofthechiller,resultinginsignificantenergysavings(watersideeconomiser).Water-cooledchillersEERcanusuallyrangebetween4and6.3.

Chillersuseeithermechanicalrefrigerationprocessesorabsorptionprocesses(Chen,ChietYan,2009).

7.5.1.1 Mechanical refrigeration chillers

Mechanicalrefrigerationchillersmayhaveoneormorecompressors.Thesecompressorscanbepoweredbyelectricmotors,fossilfuelengines,orturbines.Refrigerationsystemsachievevariablecapacitybybringingcompressorsonoroffline,byunloadingstageswithinthecompressors,orbyvaryingthespeedofthecompressor.

7.5.1.2 Absorption chillers

Absorptionchillersareheat-operateddevicesthatproducechilledwaterviaanabsorptioncycle.Absorptionchillerscanbedirect-fired,usingnaturalgasorfueloil,orindirect-fired.Indirect-firedunitsmayusedifferentsourcesforheat:hotwaterorsteamfromaboiler,steamfromdistrictheating,orwasteheatintheformofwater,air,orothergas.Absorptionchillerscanbesingle-effectordouble-effect,whereoneortwovaporgeneratorsareused.Double-effectchillersusetwogeneratorssequentiallytoincreaseefficiency.Severalmanufacturersofferabsorptionchiller/heaterunits,whichusetheheatproducedbyfiringtoprovidespaceheatingandservicehotwater.

7.5.1.3 Evaporative coolers

Evaporativecoolers,alsocalledswampcoolers,arepackagedunitsthatcooltheairbyhumidifyingitandthenevaporatingthemoisture.Theequipmentismosteffectiveindryclimates.Itcansignificantlyreducethepeakelectricdemandwhencomparedtoelectricchillers.

7.5.2 Variablerefrigerantflow(VRF)

Theterm“variablerefrigerantflow”referstotheabilityofthesystemtocontroltheamountofrefrigerantflowingtoeachoftheevaporators,enablingtheuseofmanyevaporatorsofdifferingcapacitiesandconfigurations,individualisedcomfortcontrol,simultaneousheatingandcoolingindifferentzones,andheatrecoveryfromonezonetoanother.ThisrefrigerantflowcontrolliesattheheartofVRFsystemsandisthemajortechnicalchallengeaswellasthesourceofmanyofthesystem’sadvantages.

Forbuildingsrequiringsimultaneousheatingandcooling,heatrecoveryVRFsystemscanbeused.Thesesystemscirculaterefrigerantbetweenzones,transferringheatfromtheindoorunitsofzonesbeingcooledtothoseofzonesbeingheated(VV.AA.,2010).

VRFsystemshaveseveralkeybenefits,including(Goetzler,2007):

• Installationadvantages:chillersoftenrequirecranesforinstallation,butVRFsystemsarelightweightandmodular.Eachmodulecanbetransportedeasilyandfitsintoastandardelevator.Multiplesofthesemodulescanbeusedtoachievecoolingcapacitiesofhundredsoftons.Eachmodule(orsetoftwo)isanindependentrefrigerantloop,theyareusuallycontrolledbyacommoncontrolsystem,butindependentcontrolispossibleaswell.

• Maintenanceandcommissioning:VRFsystemswiththeirstandardisedconfigurationsandsophisticatedelectroniccontrolsareaimingtowardnearplug-and-playcommissioning.Because



theyareDXsystems,maintenancecostsforaVRFshouldbelowerthanforwater-cooledchillers.However,chillers,whichoftenoperatefor20to30years,normallywouldbeanticipatedtohavealongerlifeexpectancythanaDXsystemsuchasaVRF.ThelargenumberofcompressorsinaVRFmaycreateahigherprobabilityofcompressorfailure,althoughtheredundancyalsoleadstoagreaterabilitytocontinuetooccupythespacewhilerepairsareinprogress.

TotalinstalledcostsforVRFsystemsareestimatedbysomesourcestobe5%to20%higherthanforchilledwatersystemsprovidingequivalentcapacity,butactualcostsarehighlyprojectdependent.

Ontheotherhand,VRFsystemshavehigherefficiencies,withenergysavingsof30%to40%comparedtothechillers(Goetzler,2007).

VRFsystemsaregenerallybestsuitedtobuildingswithdiverse,multiplezonesrequiringindividualcontrol,suchasofficebuildings,hospitals,orhotels.

ThemaindisadvantagesofVRFsystemsinclude(Goetzler,2007):

• Theefficiencydropsoffconsiderablyatlowtemperatures,sotheyarelesscosteffectivecomparedtogasheatinginverycoldclimates.

• Lackofawarenessofenergyefficiencyadvantages:mostindustryprofessionalsreferonlytoEERorkW/tonratingswhenconsideringefficiency.ThemoresubtleenergyefficiencyadvantagesofVRFsystems,suchasthereductioninductlosses,theeaseofelectricalsub-metering,andeventhehigherpartloadefficiency,frequentlyareoverlooked.

• Initialcost:Inmanycases,theinitialcostofaVRFsystemishigherifcomparedtoachilledwatersystem.WhileaVRFmaybecostcompetitivefornewconstruction,inachillerreplacementsituationwithexistingwaterpiping,replacingthechillerwouldnormallybelessexpensivethaninstallingaVRF.

7.5.3 KPIsevaluationforairconditioningtechnologies

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthebuildingairconditioningtechnologiesintroducedintheprevioussectionisproposed.Thetwomaintechnologiespresentedinthissection,chillersandVRF,arecomparedinthetable,inordertoprovideasimpleandclearunderstandingofeachoneprosandcons.

ThemainsourcesthatinformTable21,below,comefromthesourcescitedintherelativesectionsabove.

Table21:KPIsevaluationforairconditioningtechnologies

Theme Typeofindicator Chillers VRF

GHGEmissions Typeoffuel Electricity Electricity

Environmentalimpact TypeRefrigerantemissionintheenvironment

Refrigerantemissionintheenvironment

Environmentalimpact Level Medium-High Medium-High

Capitalinvestmentcost Installationcost 8.000–20.000 600–9.000



Theme Typeofindicator Chillers VRF

Performanceindex EER 3.2–5 3–4.8

Technologicalregime Lifetime(years) 30 10-15

Technologicalregime Maturityoftechnology High High

PoliticalcommitmentAvailableGrants&Policysupport

Yes

EER>3.4

Yes

EER>3.4

PublicopinionDegreeofacceptanceof

thetechnologyMedium–High Medium

Chillersarethemorepopularsolutionforbuildingairconditioning,astheyaretheoldertechnology.Exceptforthat,thetwotechnologiesarequitecomparableandtheuserchoicebetweenthetwoishighlydependentonthebuildingcharacteristics.Chillersareusuallybettersuitedforbiggerinstallationandwhereavailablespaceisnotanissue.VRVs,ontheotherside,havehighmodularityandtheycanbeusedforsmallinstallationssuchasanindividualapartmentorforawholebuilding,connectingmultipleunities.Possibilitiesandperformancesaresimilar,withVRVshavingusuallyalittlehigherinvestmentcostthanchillerswhenconsideringthesamepowercapacity.

Giventhelowerweightandsimplerinstallationprocess,VRVshavehigherpossibilitieswhenretrofittingoldbuildings,andarethusincreasingtheirmarketshare.

7.6 Buildingmonitoring,automationandcontrolAstechnologyisdeveloping,buildingmonitoring,automationandcontrolisassumingaincreasinglyimportantroleintheenergyefficiencyofindustrial,publicandresidentialbuildings.Theuseofsensorstocontrolthebuildingenergyperformancesandthepossibilitytoautomaticallymanagethebuildingenergyusageandcorrectdetectedfaults,canproduceamuchhighercomfortforbuildinginhabitants,reducingatthesametimetheenergyconsumption.

Thefollowingsectionswillfirstdetailthemainparametersthatneedtobeconsideredtoguaranteepeoplecomfortinsidethebuildingandwhichsensorsareusedtocontrolthoseparameters.Secondly,themainsolutioninthefieldofbuildingautomationandcontrolsystemarediscussed.

7.6.1 Comfortindoorandairquality

Theterm‘comfort’mightbeusedtodescribeafeelingofcontentment,asenseofeasinessandastateofphysicalandmentalwell-being.Indoorenvironmentalquality(IEQ)referstothequalityofabuilding’senvironmentinrelationtothecomfortofthosewhooccupyspacewithinit.IEQisdeterminedbyseveralfactors,includinglighting,airquality,anddampconditions(Chappells&Shove,2004).AsproposedintheANSI/ASHRAEStandard55-2004,buildingmanagersandoperatorscanincreasethesatisfactionofbuildingoccupantsbyconsideringalloftheaspectsofIEQratherthannarrowlyfocusingontemperatureorairqualityalone.

Belowalistoffactorsthatcontributetodefinecomfortlevels,andhowtocontrolthem.



7.6.1.1 Temperature

ThermalcomfortistheconditionofmindthatexpressessatisfactionwiththethermalenvironmentandisassessedbysubjectiveevaluationASHRAEStandard55.

Themainfactorsthatinfluencethermalcomfortarethosethatdetermineheatgainandloss,namelymetabolicrate,clothinginsulation,airtemperature,meanradianttemperature,airspeedandrelativehumidity.Psychologicalparameterssuchasindividualexpectationsalsoaffectthermalcomfort.

Sensorswhichdetecttemperatureorheatarecurrentlythemostcommonlyusedonesinbuilding.ThesetypesoftemperaturesensorvaryfromsimpleON/OFFthermostaticdevices,whichcontroladomestichotwaterheatingsystem,tohighlysensitivesemiconductortypesthatcancontrolmorecomplexfurnaceplants.

Twomaintypesoftemperaturesensorscanbedefined:

• ContactTemperatureSensor:Thesetypesoftemperaturesensorarerequiredtobeinphysicalcontactwiththeheatsourceanduseconductiontomonitorchangesintemperature.Theycanbeusedtodetectsolids,liquidsorgasesoverawiderangeoftemperatures.

• Non-contactTemperatureSensor:Thesetypesoftemperaturesensoruseconvectionandradiationtomonitorchangesintemperature.Theycanbeusedtodetectliquidsandgasesthatemitradiantenergyasheatrisesandcoldsettlestothebottominconvectioncurrentsordetecttheradiantenergybeingtransmittedfromanobjectintheformofinfra-redradiation.

7.6.1.2 Humidity

Humancomfortdependsonacomplexinteractionofmultiplevariableswithhumiditybeingonlyoneofthem.However,optimisingbothtemperatureandrelativehumiditysatisfiesthecomfortrequirementsforawidervarietyofoccupantsasopposedtoregulatingtemperatureonly.

TheASHRAEstandard55specifiesthattodecreasethepossibilityofdiscomfortduetoloworhighhumidity,itslevelhastobemaintainedbetween30%and70%relativehumidityat21°C.ThehealthandSafetyExecutiveintheUnitedKingdomrecommendsrelativehumidityintherangeof40%to70%intheworkplaceenvironment.

Humiditysensorsareemployedtoprovideanindicationofthemoisturelevelsintheenvironment.Ahumiditysensor,alsocalledahygrometer,measuresandregularlyreportstherelativehumidityintheair.Relativehumidity,expressedasapercent,istheratioofactualmoistureintheairtothehighestamountofmoistureairatthattemperaturecanhold.Thewarmertheairis,themoremoistureitcanhold,sorelativehumiditychangeswithfluctuationsintemperature.

Themostcommontypeofhumiditysensoruseswhatiscalled“capacitivemeasurement.”Thissystemreliesonelectricalcapacitance,ortheabilityoftwonearbyelectricalconductorstocreateanelectricalfieldbetweenthem,andmeasurethechangesinthevoltageduetovariationsinmoisturelevel.

Humiditysensorscanbeconnectedtothemechanicalventilationsystem,inordertoregulateandcontrolthecharacteristicsandparametersofthefreshairintroducedintotheroom.CommercialandofficebuildingsoftenhavehumiditysensorsintheirHVACsystems,whichhelptoensuresafeairquality,whiletheyarelesscommonlyusedinresidentialbuildings.Manytimes,humidityandtemperaturesensorsaresoldtogether.

7.6.1.3 Air quality

Indoorairqualityisnoteasilydefined.Itisaconstantlychanginginteractionofcomplexfactorsrelatedtothetypes,levelsandimportanceofpollutantsinindoorenvironments.Thesourcesofpollutantsneedtobe



managed,eitherbyremovingthemfromthebuildingorisolatingthemfrompeoplethroughphysicalbarriers,airpressuredifferences,orbycontrollingthetimingoftheiruse.Inthisprocess,filteringofthepollutedairisanessentialstep.Mechanicalventilationisamoresuitableoptionthannaturalventilation,sinceprovideabettercontrolofairflowdirectionandintensity,providingahigherairqualitylevel.

Inordertoprovideadequateventilationforoccupiedspaces,monitoringsystemscanbeinstalledtogeneratealarmswhenunhealthylevelsofcarbondioxidearedetectedandfreshairneedstobebroughtintorestorehealthyindoorairquality.

ACO2sensorisaninstrumentforthemeasurementofcarbondioxidelevelinindoorair.ThemostcommonprinciplesforCO2sensorsareinfraredgassensorsandchemicalgassensors.Newdevelopmentsincludeusingmicroelectromechanicalsystemtobringdownthecostsofthissensorandtocreatesmallerdevices(forexampleforuseinairconditioningapplications).

Nowadays,mechanicalventilationispresentalmostsolelyincommercialbuildingsand,eventhere,CO2sensorsarerarelyfound.

7.6.2 BuildingAutomationandControlSystems

Thegoalofbuildingoperationistoachieveoptimaloccupantcomfortwiththeleastamountofenergyconsumption.Buildingsthatachievethisbalancedosobyaddressingthetwomainelementsofbuildingperformance:

1)SystemTrackingforHVACandlightingsystems.Inatypicallargecommercialbuilding,thisinformationwillbeaccessibleviatheBAS.

2)EnergyTrackingforthewholebuilding,accessedthroughmonthlyutilitybillsandgivenvaluablecontextthroughbenchmarking.

Buildingownersshouldaddressbothsidesofthecointoreapthefullrewardsoftrackingbuildingperformance,sinceeachsidecananswerdifferentquestionsaboutbuildingoperation.

Thetwoapproachescanbedividedinthreedifferentlevelsofcomplexity,detailandautomationasshowninFigure19.Higherlevelstoolscanovercomethelimitsofthelowerlevelones,butcannotworkoptimally,ifnotworkatall,withouttheirpresence(PortlandEnergyConservation,2011).

Figure19:HVACcontrolsystemstypologies(PortlandEnergyConservation,2011)



7.6.2.1 Energy Tracking

7.6.2.1.1 EnergyBenchmarkingEnergybenchmarkingisastrategyforcheckingawholebuildingenergyconsumptionandcomparingitsenergyperformanceeithertopeergroupsortohistoricalperformance.Ithasincreasinglybecomethenormforcommercialbuildingowners,whoappreciatethevalueofthedataandease-of-useofthetools.Thesetoolsnotonlybenchmarkperformanceatapointintime,butalsoindicatewhenperformanceimprovesordegradesoveralongerperiod.Theyautomaticallygenerateclearperformancetablesandgivethepossibilitytotheusertosettargetsandcheckprogresses.Severalonlineresourcesareavailabletohelpwithbuildingbenchmarking.

7.6.2.1.2 EnergyInformationSystem(EIS)Energyinformationsystems(EIS)areusedtostore,analyseanddisplaycurrentandhistoricalenergyuse,typicallydisplayinghour-by-hourdataforeachmeter.EISprovidethecapabilityfortheusertoanalyseenergyconsumptionpatternsusingavarietyofgraphicalformats.Thishourlytrackingenablessystemimprovementstobeviewedatthemeterlevelandproblemstobemoreeasilyandquicklyidentified.Datacollectedbysensorsarecollected,analysedandarchivedintotheEISserverandtheusercanaccesstheminavarietyofformatsonawebinterface.

EIShelpfindandfixproblemsfasterandareausefultooltochecktheresultsofefficiencyinvestment.Thelimitsofthisleveloftoolsisthattheyprovideaviewonhowthebuildingbehaved,butanyonhowitshouldbehave.ThisissueisfixedwiththeintroductionofAdvancedEIS.

7.6.2.1.3 AdvancedEISAdvancedEISincludethesamefeaturesofEIS,addinganewleveloffeaturesandpossibilities.Theycantrackandgraphicaldisplayhourlyenergyuse,takingintoaccountmanyvariablesthataffecttheenergyuse:outsideairtemperature,daytype(weekend/weekdayordayoftheweek),andhour-of-dayaretypical,butothervariablessuchasbuildingoccupancylevelsmayalsobeused.

Inaddition,thesesystemsincorporatesophisticatedenergymodellingfunctionalitythatcan,overaperiodofmanymonthstooneyear,developamodeltopredictexpectedenergyusebasedonanumberofvariables,andalerttheuserifenergyuseexceedsthatprediction.Acomparisonof‘typicalvs.actual’energyusecanthenbeusedtoautomaticallygeneratealertswhendifferencesoccur.

7.6.2.2 System Tracking

7.6.2.2.1 BuildingAutomationSystem(BAS)MostlargebuildingsuseaBAStocontrolabuilding’sHeating,VentilatingandAirConditioning(HVAC)andlightingsystems.BAScanvarywidelyincapabilitiesandconfiguration,butonthebasiclevel,theycontainaninstantaneousdisplayofthebuilding’scurrentoperation,includingdatareadingsfromhundredsorthousandsofdatapointsfromHVACandlightingsystems,alongwiththeprogrammingnecessarytocontrolsystemoperation.

TheBASplaysakeyroleinallbuildingperformance-trackingstrategies,becauseitcanbeusedfortroubleshootingsystemperformanceproblems.UsingtheBASasaperformancetrackingtoolbeginswithtrendloggingtorecordtheperformanceofsystemsundervariousmodesandoperatingconditionsovertime.Archivingthetrendeddataisakeystepinmakingsurethedataispreserved.Inadditiontotrends,BASalarmscanbeconfiguredtoexposeasystemfault,aproblemrelatingtooccupantcomfort,oranoccupant-drivenchangewithadamagingimpactonenergy.TypicalBASalarmswillsignalwhenadata



pointisoutsideofapredeterminedthreshold.AllBAShaveinherentalarmcapabilitiesthatdonotrequirecustomprogrammingbyacontrolscontractor.

Afterdiscoveringperformanceproblems,eitherthroughtrendlogsandBASalarmsoranyotherperformancetrackingtool,thenextstepistofindthespecificproblem,includingitsrootcause.AllperformancetrackingtoolsrequireoperatorstousetheBAStodiagnoseproblems,evenifthosetoolscanautomaticallydetectfaults.

Afterfixingperformanceissues,theBAScanbeusedtoverifythatperformancehasimprovedbyobservingdataattheoperatorworkstationandreviewingtrends.Thisstepassuresoperatorsthattheproblemhasbeenfixedandofteninvolvestweakingoperatingparameterstooptimisetheimprovementsratherthanoverridingthementirely.Also,BASalarmthresholdsmayneedtoberevisedbasedonthenewoperatingconditionsoftheequipment.

7.6.2.2.2 BASMetricsUsingtheBAStotrackkeyperformancemetricscanbeaneffectiveandinexpensivewaytoboildownthethousandsofdatapointsthatmaybetrackedintomoreuserfriendlyinformation.TheBAScantrackthousandsofpointswithinabuilding;thedistinctionwithametricisthatthesecondonecombinesdatafrommultiplepointstoprovidedeepermeaning.Thisminimisesdailylabourresourcesrequiredandprovidesawaytotracklongtermbuildingperformanceimprovements.

Forexample,trackingzonetemperaturesisimportantforensuringcomfort,butreviewingtemperaturesineveryzoneisdifficulttomanagelong-term.Trackingametricsuchasthepercentoftimewhenzonesarewithinsetvaluescanbeusefulforassessingperformanceataglanceandfortrackingimprovementordegradationovertime.

MostBAShavethecapabilitytotrackenergy-relatedmetrics,aslongasmeterdatacanbeinputtotheBAS,sometimesrequiringtheadditionofnewsensors.

SomeofthemostrecommendedBASmetricare,forexample,OccupantComfortIndex,Cooling/HeatingPlantEfficiency,FanSystemEfficiency,OutsideAirVentilation.

Metrictrackingminimisesdailylabourresourcesrequiredandprovidesaneasywaytotracklongtermimprovementsonamonthlyorannualbasis.Addingthisfunctionalitytoanalready-familiarBAStoolshouldminimisetheadditionaleffortrequiredforoperatorstotrackmetrics.

Trackingacomfort-relatedmetricisparticularlyuseful,andmakepossibletoidentifyproblemsbeforeanyoccupantcomplaintsarereported.

Thelimitsofthisapproacharethatinmostofthecasesmetricsarebuildingspecifics.Agoodknowledgeofthebuildingisrequiredinordertounderstandwhatthenormalbehaviourofthemeasuredmetricsis.Moreover,thesetoolsstilllackadiagnosisability,whichisintroducedonlyinFDD.

7.6.2.2.3 FaultDetectionandDiagnosis(FDD)FDDtoolsutilisesystem-levelperformancedatatoautomaticallydetectproblems.Sometoolsadditionallyprovidediagnosticstohelpdeterminetherootcauseoftheproblem.

FDDtoolsrelyonBASdatawithafewtoolsrequiringtheinstallationofdedicatedsensorsexternaltotheBAS.Theymayincludeasinglesystem,suchasanairhandlerormultiplesystemsthroughoutthefacilitysuchasair-handlers,pumps,chillers,boilers,etc.

Problemsaretypicallydetectedusingthefollowingtechniques:



• Expertrulesmimicthethinkingofasystemsexperttocomparemultipledatapoints.Inmanycases,theexpertuse“if-then”rules,tocheckthesystemoperationrelativetoknownorexpectedoperation.

• PerformancedatacomparisonsevaluatemonitoredBASdataagainstcertainparameters,suchasdesignintent,manufacturers’equipmentratings,andhistoricaltrenddata.Amodelofexpectedperformanceiscreatedandisthencomparedtotheactualperformancevalues.

Inadditiontoindicatingproblems,expertrulescanaccountforthedurationorcumulativecostimpactofaparticularproblem,assigningaprioritylevelconsequently.

Sometoolsonlypinpointthelocationofthefaultwithoutprovidingspecificcauses,whileothersmayissueareportwithdiagnosticpossibilitiesforcorrectiveaction.Ineithercase,additionalmanualinspectionorfurtheranalysismayberequired.

7.6.3 KPIsevaluationforbuildingautomationandcontrolsystems

Inthefollowingtable,themainparametersforabriefmulti-levelcomparisonbetweenthebuildingautomationandcontrolsystemsintroducedintheprevioussectionisproposed.Ithelpsgivingaclearandsimpleunderstandingofeachtechnologystrengthandweaknesstowardsalowcarbonfuture.

ThemainsourcesthatinformTable22,below,comefromPortlandEnergyConservation(2011)andVV.AA.(2010).



Table22:KPIsevaluationforbuildingautomationandcontrolsystems

Theme TypeofindicatorEnergy

BenchmarkingEIS AdvancedEIS BAS BASMetrics FDD

Capitalinvestmentcost Averagemarketprice

Low Medium Medium–High Medium Low-Medium High

CapitalinvestmentcostAverageannualenergysavings* n.a. n.a. 10-30% n.a. n.a. 10-30%

Technologicalregime Operation Tracksenergyconsumption

Tracksandsaveenergy

consumption

Data-basedbuildingmodel(TypicalvsActual)

ErrordetectionProvideatool

forfaultdiagnosis

AutomaticErrordetectionanddiagnosis

Technologicalregime Control Semi-Automatic Semi-Automatic AutomaticSemi-

AutomaticSemi-

AutomaticAutomatic

TechnologicalregimeMaturityoftechnology

Medium-High Medium-High Medium Medium-High Medium-High Medium

Politicalcommitment AvailableGrants&Policysupport

EuropeanDirective2012/27EUonEnergyefficiency



Medium–High Medium Low–Medium Medium–High Medium–High Low-Medium

*Comparedtobuildingwithoutanybuildingautomationandcontrolsolution



MultipledifferentsolutionsexistonthemarketwhenreferringtoBuildingAutomationandControlSystems.Themoreadvancedisthetoolthemorefunctionalitiesitprovides,increasingthelevelofautomationandthepossibilitiesofcontrolonthebuildingenergeticperformances.Thepricefollowsthisevolution,withhighercostformoreadvancedandcompletetools,withFDDusuallyhavinghighercostthanAdvancedEIS.

Overall,thosetoolsaremainlyimplementedincommercialbuildingsandareseeinganincreaseintheirmarketshare.NospecificpolicyisdefinedforimplementingBACSsystemsatEuropeanlevel,buttheyareconsideredasmeasurestoimprovebuildingefficiencyandavailablegrantsandsupportdependsontheefficiencyleveltheyallowthebuildingtoreach.

Comparingthedifferentsolutionproposed,thereisnorealpreferencebetweenAdvancedEISandFDD,astheyservedifferentpurpose.Toobtainthebestpossiblelevelofbuildingcontrolandautomation,itishighlyadvisabletoimplementbothsolutiontogether.

7.7 TransportTransportisaveryindicatingsectorinanenergyandenvironmentalimpactanalysis,sinceitsenergydemandisnearonequarterofthetotalenergyconsumptionworldwide,withhugeeffectsonoursocietycarbonfootprint,CO2andotherGHGemissions.Inparticular,privatetransportsector(i.e.,themethodstomovepeoplebyusingtheirownrelativelylittlesizedvehicleslikecarsormotorcycles).

Inthissection,severaldifferentprivatetransportmethodsareanalysedandcomparedinanend-userperspective,withthemainfocusonthedifferentpropulsionmethodslikethetraditionalcarbon-basedones(i.e.,gasolineanddieselcars)andtheinnovativesolutionsbasedonlessCO2emittingelectricpropulsion(hybridandfullhybridcars).

Inparticular,theirtechnicalfeaturesareinvestigatedwithmainreferencetoageneralperformanceevaluationoftheirenergydemand,environmentalimpactandsocialacceptancebymeanoftheKPIssetdefinedinChapter3.

Inordertoperformthisassessment,themainlyusedprivatetransporttechnologiesaretakenintoaccount:gasoline,diesel,hybridandelectriccars.

7.7.1 Privatetransportvehicles7.7.1.1 Gasoline

Withits130yearshistory,gasolinevehiclesrepresentthemostmatureprivatepeopletransporttechnologyinthecurrentscenario.Atthetimebeing,thisisoneofthemostadoptedmethodsandthegasolinecarsmarketisstilllarge(in2013,about45%ofnewregisteredcarswasrepresentedbygasolinecars),evenifthenewdiffusedenvironmentalconcernsarepushingtowardsmostinnovativeandenergyeffectivevehicles.

Indeed,themaindisadvantageisthehighCO2emissionsofthispropulsionmethod,ifcomparedtootherengineslikedieselorelectricones.Withanaveragegasolineconsumptionof6.3l/100kmforgasolinecars,thesevehiclesemitintheatmosphereabout150gCO2/km.

Inordertoreducethecarbonfootprintduetotheprivatetransportsector,someEuropeanMemberStateshavecreatedtaxincentivestopromoteswitchingtolessCO2intensivetechnologies,likehybridvehicles.

Duetothelowerpriceofagasolinecarcomparedtothediesel-propelledversionofthesamemodel,oftenpeoplestillpurchaseagasolineoneinspiteofthehighercarbonfootprint.Thisisespeciallytrueinthesegmentofsmallvehiclesandcitycars,whicharenotaimedatbeingdrivenformanykilometresperyear.



7.7.1.2 Diesel

Dieselpropulsionvehiclesappearedin1930s,whichmakesitaverymaturetechnologywithalongworldwidehistory.ThisisthemostusedcartechnologycurrentlyinEurope:accordingtoyear2013marketdata,53%ofthepurchasedprivatecarshaddieselengine(ICCT,2014).Thisisduetothelowermeanfuelconsumptionofthiskindofvehiclesifcomparedtothesameclassgasoline-propelledcars,thismakingitcheaperdrivingsuchavehicle.

Infact,themeanfuelconsumptionfordieselcarsisaround3.8l/100km:furthertheobviouseconomicadvantages,dieselenginesarelessemittingthangasolineones,withaCO2productioncloseto100gCO2/km.

So,bothforeconomyandenvironmentreasons,dieselcarstendtobepreferredinthebigvehiclessegment,eveniftheirpurchasingpricesarehigher.

7.7.1.3 Hybrid

Incontrasttopreviouslydescribedinternalcombustioncars,hybridvehiclesusetwoormorecombinedpropulsionmethodinordertoachieveanoptimisedenergyefficiency.Inthissection,hybridelectricvehicles(HEV)aretakenintoconsideration,usinganinternalcombustionengine(gasolineordieselengine)andanelectricmotorfedbyabatteryset.Theelectricmotorsharestheloadwiththeinternalcombustionengine,whichcanbeoptimallysizedforfuelefficiencyandcleanburning(i.e.,alowcylindercapacitycanbeadoptedfortheseengines).

Differenttypologiesofhybridvehicleworkingcanbedefined:fullhybrids,mildhybridsandplug-inhybrids(Cobb2014).

Fullhybridvehiclesrepresentthemostfuelefficientvarietyofhybrids.Theirpeculiarityistheabilitytoautomaticallychoosethepropulsionmodebetweenseries,parallelandall-electricmode,whicharefollowingexplained.

Theseriesmodeusestheinternalcombustionengineasanon-boardgeneratortofeedtheelectricmotor,drivingthewheels.Inparallelmode,boththeengines(fuel-basedandelectric)cooperatetomovethewheels.Inparticularregimes,suchaslowspeeds,whenlowenergyamountisrequired,thebatterysetandelectricmotorcandrivethevehiclewithoutthehelpofthecombustionengine,inapureelectricmode.

Mildhybridsarelimitedtoparallelmode:thevehiclenevercanbedrivenwithouttheinternalcombustionenginepropulsion.Inthiscase,theelectricmotorworksasahelpermotor.

Plug-inhybridcarscanbedirectlypluggedintotheelectricitygrid,andtheyhavelargerbatterieswhencomparedtootherhybridtypologies,givingthesekindofvehicleautonomiesupto60kminthefullelectricmode.Whendrivenbyfuelandelectricmotorstogether,theycanworkbothinseriesandparallelmode.

Today,hybridprivatevehiclesdiffusionisnotsowide,butisgrowingthankstopublicenvironmentalconcernsandtheirlowerGHGemissionswhencomparedtotraditionalfuel-basedcars.ReferringtotheEuropeanmarketshare,only1.4%ofpurchasedvehicleswashybridduring2013(ICCT,2014).

Ontheotherhand,someEUMemberStateslikeNetherlandsareproposingtaxincentivesforpeoplepurchasingahybridvehicle,thisputtingthesecountriesmuchabovetheEuropeanaveragereferringtothenewhybridcarsregistrations(10%ofthetotalcarmarketsharein2013).

7.7.1.4 Electric

Electricvehicles(EV)arevehiclespropelledonlybyoneormoreelectricmotors,whicharefedbyabatteryset.Inthecaseofplug-inelectricvehicles(PEV),anyexternalelectricitysourcecanbeusedtorechargethebatteries.



Themainadvantagesofthiskindofprivatevehiclesarethelowcarbonfootprint(theelectricmotorismoreefficientthaninternalcombustionone,anditdoesnotproduceGHGwhereitisused)andthelowenergycostsifcomparedtothetraditionalcars.

Oneofthedrawbackswhicharestillrestrainingpeoplefromswitchingtofullelectricprivatetransportistheperformance(maximumspeedsofthesevehiclesaregenerallylowerthantraditionalcars,thusmeaningelectriccarsarenotassuitableforlongdistances).

Anotherproblemwhichelectriccarsdrivershavetofacewithisrange,whichisshort(batteriescangivepowertotheelectricmotorformaximumroutesof240km)andunstable(externaltemperatures,withsubsequentuseofheatingorairconditioning,canstronglyaffectrealrangevalues).

WithaEuropeanmarketshareof0.4%in2013electricvehiclesaretheleastpopularvehicletype,theyalsorepresentthenewestprivatetransporttechnology(ICCT,2014).

Fromanenvironmentalpointofview,thesevehiclesaretheoreticallyzero-emittingifweconsidertheplaceandthemomentinwhichtheyareused.Nevertheless,electricityproductionisnotazero-emittingprocess,noristhemanufacturingprocessesrequiredtomakethevehiclesthemselves.Therefore,wemustconsiderthesefactorsalongwithimpactofassociatedpollutionlevelstakenonaworldwidescale.

Inparticular,ifweconsideranelectricityabsorptionof13kWh/100kmforthistypeofcar,andanaverageEuropeanCO2emissionof500gCO2/kWh,therealemissionsforthesevehiclesare65gCO2/km.Thisestimationstillmakeselectriccarsthecleanestoptionintheprivatetransportscenario.

7.7.2 KPIsevaluationforprivatetransportvehiclesInTable23,below,themainKPIsforatechnical,economicandenvironmentalcomparisonbetweenthedifferentanalysedtechnologiesforprivatetransportareshown.Theseparametershelpacategorisationnofthedifferentvehiclestypologies,whicharedescribedinthesectionsabove.

Themainsourcesusedinthistablecomefromthesamereferencesquotedineachspecifictechnologysection,inadditiontoanumberofcarmanufacturerstechnicaldatasuchasFordFocus1.5and1.6,Lexus(2016),Renault(2016).Moreover,datawasalsotakenfromtheACEA(2015).

Table23:KPIsevaluationforprivatetransportvehicles

ThemeTypeofindicator Gasoline Diesel Hybrid Electric

Pollutinggasemissions

gCO2/distance 150g/km 100g/km 82g/km

0g/km(65g/kmconsideringelectricityproduction)


Technology

price

20,000€Error!

Bookmarknot

defined.

21,000€Error!

Bookmarknotdefined.

28,000€Error!

Bookmarknotdefined.

22,000€


Fuelcost 1.26€/l 1.08€/l 1.26€/l 0.22€/kWh



ThemeTypeofindicator

Gasoline Diesel Hybrid Electric

Performanceindex Consumption

6.3l/100kmError!Bookmark

notdefined.

3.8l/100kmError!Bookmarknotdefined.

3.6l/100kmError!

Bookmarknotdefined.

13kWh/100kmError!

Bookmarknotdefined.

Technologicalregime

Lifespan300.000

km300.000km 240.000km 200.000km

Technologicalregime

Maturityof

technologyHigh High Medium-High Low-Medium

Politicalcommitment

Available

Grants&

Policysupport

- -

Taxexemptionsin

someEUMemberStates

ResearchsupportedinFP7

TaxexemptionsinsomeEU

MemberStates

PublicopinionMarketshare-

market

increase

45%

(-5%since2009to2012)

53%

(+8%since2009to2012)

1.4%

increasing

0.4%

increasing

Analysingthedataintheabovetable,wecanseetheincreasingenergyefficiencyofeachoftheproposedtransporttechnologies,startingfromthemosttraditionalfuel-basedpropulsionenginesandmovingtowardstheinnovativehybridandelectricvehicles.Theseareframedbothintermsofaneconomicalpointofviewandtherelativecost-effectivenessofdrivingavehicleincreasesaswemovetowardselectricmodels.

Moreover,asshowninTable23,hybridandelectricvehicleshavelowercarbonfootprintifcomparedtotraditionalinternalcombustion-propelledcars.Ontheotherhand,theystillhavealittlemarketshareduetotheirshorttechnologicalmaturity,andthelifespanofasingleelectricmotor-drivenvehicleisshorterthanotherones.Themainreasonforthisshorterlifespanisthebatterywear,whichcannotbelongerthan200.000kmatthestateoftheart.

Hybridcars,thankstotheloadsharingbetweenelectricmotorandcombustionengine,havetheadvantageofalongerlifespanifcomparedtopureelectrics.



8 Conclusionandsynthesis

ThegoalofT2.2hasbeentoprovideatechnologicalcharacterisationoftheEuropeanenergysystem,

followingtheenergysupplychain,andaugmentingtheinformationcapturedduringearliertasksinvolving

thevariousthestakeholdersandtheactor-networkapproaches.Indoingso,thefourmainstagesofthe

supplychainhavebeenanalysedandthemaintechnologicaldrivingforcesforeachoneofthemhasbeen

presented.Anextensivedatagatheringexercisewasconductedtodevelopaclearviewofeachtechnology

consideredandtoprovideasimplebutcompletedescription.Moreover,thereviewedtechnologieshave

beengroupedintosimilarlybasedcategories,andasetofspecificKeyPerformanceIndicatorshavebeen

definedforeachcategoryinordertocomparethemandprovideaclearerviewofthestrengthsand

weaknessesofeachtechnologicaloptionaswemovetowardsalow-carbonenergysystem.

MergingtogethertheinformationgatheredduringbothTask2.1andTask2.2,itisclearhowcomplexand

variegatedtheenergysystemisandhowmanyfactorshavetobetakenintoaccountwhendescribingit.In

thisparticulardocumentitispossibletogainanunderstandingofhowtheenergysystemhaschangedover

thecourseofthepastfewdecades,changesthathavebeeninformedbygrowingconcernsover

environmentalissuesandtheawarenessthatthecurrentsituationisnolongersustainable.Thetraditional

system,characterisedbyhighly-centralisedenergyproductionmodelsandbytheextensiveuseoffossil

fuels,remainsdominantbutimportantstepsarebeingdonetowardsagrowingexploitationofcleanand

renewableenergies.Manydifferentsolutionsarealreadyavailableinthemarketandarebeingsuccessfully

implemented.Thisisthecaseforwindandsolar,whichhaveseenthemostimportantgrowthinthelast

tenyears,duetotheircontributionsinreducingGHGemissions,technologyreadinessandmodularity.They

mayalsoprovetobeagoodsolutionforbothsmallandplant-sizedinstallationsforhighly-developed,

urbanisedareasandinmoreruralareaswithlimitedaccesstothenationalgrid.

Theimprovementsthathavebeenmadetotheenergysystem,though,havenotbeensolelyrestrictedto

theimplementationofnewgreentechnologiesasareplacementfortraditionalfossilfuelledones.Whatis

shapingisalsoshapingitsfutureisaroundDistributedGeneration,withstrongerinterconnectionsbetween

bigpowerandheatplantsandbuildingindividualsolutions,withthepotentialforatwo-wayflowofenergy

basedontheenergydemandvariationsduringthedayandonthepeak-loadperiodsassociatedwith

renewableenergies.Theelectricalgridneedstobeamplifiedandupgradedtosustainfrequentchangesin

electricitydirectionandpowerlevels.Naturalgaspipelineswillalsoseeasimilarprocessesofdevelopment

toallowforchangesingasflowdirectionduringparticularlycoldwinters.Storageisbecomingincreasingly

importantduetothevariablenatureoftherenewableenergiessuchaswindandsolar,inordertostore

energyduringpeak-loadperiodsanduseitbackwhenmostneeded.

Ithasalsoshowntheimportanceofsolutionsthatprovideelectricityandheatatthesametime.Combined

heatandpowerplantscangreatlyimproveefficiencywithrespecttotraditionalpower-onlyplants,wherea

lotofprocessheatiswasted.Theuseofdistrictheating,incombinationwithCHPplants,isanextremely

efficientsolutionespeciallywhentheCHPplantisfiredfromrenewableenergiessuchasbiomassor

municipalwaste,andisasolutionthathasbeenmuchencouragedbytheEU.Thisdespitethisemphasisat

thesupranationallevel,districtheatingremainslargelyconfinedtoNorthernandEasternregionsof

Europe.



Anotherrelevantpointtonoteistheneedofgreaterefficiency,notonlyintermsofenergygeneration,but

alsoinenergyfinaluse.ThisoneofthethreekeytargetsoftheEurope2020strategy,withaproposed20%

improvementinenergyefficiency.Thisdocumentalsorevieweddifferentsolutionsforautomationand

controloflightingandHVAC,withadiscussionontheirimportanceinbothenergysavingopportunitiesand

providedcomforttopeople.

Overall,thisdocumenthasprovidedanextensiveoverviewofthetechnologiescontributingtoenergy

supplysystem,constitutingafurtherstepintheframeworksetoutfortheENTRUSTproject.The

informationcollectedinbothTask2.1andTask2.2showsushowtheshifttowardsacarbon-freeenergy

systemiswhollynecessary,butstillremainsfarfromacompleteintermsofimplementation.Renewable

energytechnologiesandefficiencymeasuresarebeingcontinuallybeingintroducedandexisting

technologiesareundergoingrapidevolution.However,atleastforthenearfuture,traditionalfossilfuel

technologieswillcontinuetobeneededifwearetoprovideasecureandstableenergysystemthroughout

theEuropeanUnion.



9 Bibliography

ACEA.(2015).OverviewofpurchaseandtaxincentivesforelectricvehiclesintheEUin2015.[Online]Availableat:https://www.acea.be/uploads/publications/Electric_vehicles_overview_2015.pdf[Accessed:15/11/2015].

AEGPowersolutions.(2016).BatteryEnergyStorageforGridStabilization.[Online]Availableat:https://www.aegps.com/en/applications/storage-distribution/battery-energy-storage/[Accessed14/11/15.

Aereco.(2016).Ventilationtechniques.[Online]Availableat:http://www.aereco.co.uk/ventilation-techniques[Accessed:15/11/2015].

Altenergymag.(2007).NaturalGashydratesandtheirPotentialityforFutureenergysupply.[Online]Availableat:http://www.altenergymag.com/article/2007/06/natural-gas-hydrates-and-their-potentialityfor-future-energy-supply/331/[Accessed:10/11/2015].

ANSI/ASHRAE.(2004).ThermalEnvironmentalConditionsforHumanOccupancy.Atlanta,USA:ASHRAEStandard.

AssociationforDecentralisedEnergy.(2016).Policiesandincentives.[Online]Availableat:http://www.theade.co.uk/policies-and-incentives_2969.html[Accessed:10/01/2016].

AtkinsonJ.,ChartierY.,andPessoa-SilvaC.L.(2009).Naturalventilation.[Online]Availableat:http://www.ncbi.nlm.nih.gov/books/NBK143277/[Accessed:11/11/2015].

Beamon,B.M.(1999a)Measuringsupplychainperformance,InternationalJournalofOperationsandProductionManagement,19:275-292

Beamon,B.M.(1999b)Designingthegreensupplychain,LogisticsInformationManagement,12:332-342

Beamon,B.M.(2008)Sustainabilityandthefutureofsupplychainmanagement,OperationsandSupplyChainManagement,1:4-18.

BermanB.(2011).HistoryofHybridVehicles.[Online]Availableat:http://www.hybridcars.com/history-of-hybrid-vehicles/[Accessed:11/10/2015].

BetzH.D.,SchumannU.,andLarocheP.(2009).Lightning:Principles,InstrumentsandApplications.NewYork:Springer,pp.202–203.ISBN978-1-4020-9078-3.

BloombergNewEnergyFinance.(2013).WorldEnergyPerspective.CostofEnergy.Technologies.London:WorldEnergyCouncil.

Bowen,B.H.,&Irwin,M.W.(2007).CoalTransportationEconomics.CCTRBasicFactsFile#7.[Online]Availableat:https://www.purdue.edu/discoverypark/energy/assets/pdfs/cctr/outreach/Basics7-Transportation-Apr07.pdf[Accessed:12/11/2015].EnergyCenteratDiscoveryParkPurdueUniversity.

Brandshaug,T.,Christianson,M.,andDamjanac,B.(2001).TechnicalReviewoftheLinedRockCavern(LRC)ConceptandDesignMethodology:MechanicalResponseofRockMass.Minnesota,U.S.A:U.S.DepartmentofEnergy.

Cabeza,L.F.,Galindo,E.,Prieto,C.,Barrenche,C.andFernandez,A.I.(2015)KeyPerformanceIndicatorsinthermalenergystorage:Surveyandassessment,RenewableEnergy,83:820-827

CALMAC.(2016).Howthermalenergystorageworks.[Online]Availableat:http://www.calmac.com/how-energy-storage-works[Accessed:11/01/2016].

CalnetixTechnologiesLlc.(2016).AdvantagesofFlywheels.[Online]Availableat:http://www.calnetix.com/resource/flywheels/advantages-flywheels[Accessed:20/01/2016].

Carlucci,D.(2010).Evaluatingandselectingkeyperformanceindicators:anANP-basedmodel.MeasuringBusinessExcellence,14(2),66–76.[Online]Availableat:http://doi.org/10.1108/13683041011047876[Accessed:21/11/2015].



Cen,K.,Chi,Y.,andYan,J.(2009).ChallengeofPowerEngineeringandEnvironment,ProceedingsofInternationalConferenceonPowerEngineering2007.Hangzhou,China.

Chappells,H.,andShove,E.(2004).COMFORT:Areviewofphilosophiesandparadigms.Lancaster,UK:EconomicandSocialResearchCouncil.

Chae,B.K.(2009).Developingkeyperformanceindicatorsforsupplychain:anindustryperspective.SupplyChainManagement:AnInternationalJournal,14(6),422–428.[Online]Availableat:http://doi.org/10.1108/13598540910995192[Accessed:11/12/2015].

Chen,J.(2011).RenewableEnergySupplyChains.WashingtonD.C.

CLEAR.(2016).Mechanicalventilation.[Online]Availableat:http://new-learn.info/packages/clear/thermal/buildings/active_systems/mv/index.html[Accessed:12/01/2016].

Cobb,J.(2014).TheThreeMainTypesOfHybridsExplained.[Online]Availableat:http://www.hybridcars.com/the-three-main-types-of-hybrids-explained/[Accessed:11/10/2016].

Coenen,L.,Benneworth,P.,&Truffer,B.(2012).Towardaspatialperspectiveonsustainabilitytransitions.ResearchPolicy,41(6),968–979.doi:10.1016/j.respol.2012.02.014

Compressionjobs.com(2010).Storagetanksandvessels.[Online]Availableat:http://articles.compressionjobs.com/articles/oilfield-101/5130-storage-tanks-vessels-gas-liquids[Accessed:11/10/2015].

CrossBorderBioenergy.(2012).EUHandbook-DistrictHeatingMarkets.Brussels,Belgium:AEBIOM.

CulhamCentreforFusionEnergy.(2012).Introductiontofusion.[Online]Availableat:http://www.ccfe.ac.uk/introduction.aspx[Accessed:25/11/2015].

Crabbé,A.,Jacobs,R.,VanHoof,V.,Bergmans,A.,&VanAcker,K.(2013).Transitiontowardssustainablematerialinnovation:evidenceandevaluationoftheFlemishcase.JournalofCleanerProduction,56,63–72.doi:10.1016/j.jclepro.2012.01.023

Cucchiella,F.,&Adamo,I.D.(2013).IssueonsupplychainofrenewableenergyEnergyReturnonInvestment.EnergyConversionandManagement,76,774–780.[Online]Availableat:http://doi.org/10.1016/j.enconman.2013.07.081[Accessed:20/11/2015].

DEFRA(2006)EnvironmentalKeyPerformanceIndicators:ReportingGuidelinesforUKBusiness,DEFRA:London

DEFRA(2013).IncinerationofMunicipalSolidWaste.London,London,UK:DepartmentforEnvironmentFood&RuralAffairspublications.

Devitt,D.(2010).MakingaCaseforFlywheelEnergyStorage.[Online]Availableat:http://www.renewableenergyworld.com/articles/print/rewna/volume-2/issue-1/storage/making-a-case-for-flywheel-energy-storage.html[Accessed:11/11/2015].

Directorate-GeneralforInternalPolicies.(2009).GasandOilPipelinesinEurope.PolicyDepartment,EconomicandScientificPolicyA.PE416.239(IPA/A/ITRE/NT/2009-13).[Online]Availableat:http://www.europarl.europa.eu/document/activities/cont/201106/20110628ATT22856/20110628ATT22856EN.pdf[Accessed:11/10/2015].

Dizdaroglu,D.(2015)Developingmicro-levelurbanecosystemindicatorsforsustainabilityassessment,EnvironmentalImpactAssessmentReview,54:119-224

EASAC.(2009).TransformingEurope’sElectricitySupply.EuropeanAcademiesScienceAdvisorCouncil.[Online]Availableat:http://www.easac.eu/home/reports-and-statements/detail-view/article/transforming.html[Accessed:16/11/2015].

Eaton,E.(2014).ResidentialLightingControlsMarketCharacterization.Boston,USA:CEE.

EDFEnergy.(2016a).Howelectricityisgenerated.[Online]Availableat:http://www.edfenergy.com/energyfuture/generation-gas[Accessed:13/10/2015].



EDFEnergy.(2016b).Nuclearenergy.[Online]Availableat:http://www.edfenergy.com/future-energy/energy-mix/nuclear[Accessed:11/01/2016].

EEA.(2016).OverviewoftheelectricityproductionanduseinEurope.EuropeanEnergyAgency.[Online]Availableat:http://www.eea.europa.eu/data-and-maps/indicators/overview-of-the-electricity-production/assessment[Accessed:21/01/2016].

EEG.(2012).Facilitatingenergystoragetoallowhighpenetrationofintermittentrenewableenergy.Munich,Germany.Store-project-IntelligentEnergyEuropeprogramme.[Online]Availableat:https://ec.europa.eu/energy/intelligent/projects/en/projects/store[Accessed:20/11/2015].

EESI.(2016).WhatIsDistrictEnergy?[Online]Availableat:http://www.districtenergy.org/assets/pdfs/White-Papers/What-IsDistrictEnergyEESI092311.pdf[Accessed:20/01/2016].

EIA.(2015).AnnualEnergyOutlook2015,withProjectionsto2040.Washington,USA:U.S.EnergyInformationAdministration.

EIA.(2016a).WeeklyNaturalGasStorageReport.U.S.EnergyInformationAdministration.[Online]Availableat:http://ir.eia.gov/ngs/ngs.html[Accessed:20/01/2016].

EIA.(2016b)TheBasicsofUndergroundNaturalGasStorage.U.S.EnergyInformationAdministration.[Online]Availableat:https://www.eia.gov/naturalgas/storage/basics/[Accessed:20/01/2016].

Electropaedia.(2016).BatteryandEnergyTechnologies:Energyefficiency.[Online]Availableat:http://www.mpoweruk.com/energy_efficiency.htm[Accessed:11/01/2016].

ElSaadany,A.M.A.,Jaber,M.Y.,&Bonney,M.(2011).Environmentalperformancemeasuresforsupplychains.ManagementResearchReview,34(11),1202–1221.

EnergyGov.(2016a).SolarEnergyTechnologyBasics.[Online]Availableat:http://energy.gov/eere/energybasics/articles/solar-energy-technology-basics[Accessed:13/01/2016].

EnergyInformative.(2016).Tidalprosandcons.[Online]Availableat:http://energyinformative.org/tidal-energy-pros-and-cons/[Accessed:11/01/2016].

EnergyInternational,Inc.(2002).StirlingEngineAssessment.PaloAlto-California,USA:EPRI

EnergyStorageAssociation.(2016).FlowBatteries.[Online]Availableat:http://energystorage.org/energy-storage/storage-technology-comparisons/flow-batteries[Accessed:20/01/2016].

Energy.Gov.(2016).HydrogenStorage.U.S.A.OfficeofEnergyEfficiency&RenewableEnergy.[Online]Availableat:http://energy.gov/eere/fuelcells/hydrogen-storage[Accessed:23/10/2015].

Energy.Gov.(2016b).TypesofHydropowerPlants.U.S.A.OfficeofEnergyEfficiency&RenewableEnergy[Online]Availableat:http://energy.gov/eere/water/types-hydropower-plants[Accessed:25/01/2016].

EnergyStar.gov(2016).ENERGYSTARMostEfficient2016—Boilers.[Online]Availableat:https://www.energystar.gov/index.cfm?c=most_efficient.me_boilers[Accessed10/01/2016].

Eurelectric.(2016).WaterandElectricity:Howitworks.[Online]Availableat:http://www.eurelectric.org/water[Accessed:25/01/2016].

EuropeanCommission.(2007).EnergyTechnologies,Knowledge–Perception–Measures.Brussels,Belgium:DirectorateGeneralforResearch.

EuropeanCommission.(2011).EnergyRoadmap2050.Luxembourg:JointResearchCentre.[Online]Availableat:https://ec.europa.eu/energy/sites/ener/files/documents/2012_energy_roadmap_2050_en_0.pdf[Accessed:11/10/2015].

EuropeanCommission.(2012a).BackgroundReportonEU-27DistrictHeatingandCoolingPotentials,Barriers,BestPracticeandMeasuresofPromotion:Luxembourg:JRCScientificandPolicyReports.



EuropeanCommission.(2012b).BestavailabletechnologiesfortheheatandcoolingmarketintheEuropeanUnion.Luxembourg:JRCScientificandPolicyReports.

EuropeanCommission.(2012c).2013TechnologyMapoftheEuropeanStrategicEnergyTechnologyPlan:Luxembourg:JRCScientificandPolicyReports.

EuropeanCommission.(2016a).Nuclearenergy.Safenuclearpower.[Online]Availableat:http://ec.europa.eu/energy/en/topics/nuclear-energy[Accessed:12/01/2016].

EuropeanCommission.(2016b).EUtoinvest€150millioninenergyinfrastructure.[Online]Availableat:https://ec.europa.eu/energy/en/news/eu-invest-%E2%82%AC150-million-energy-infrastructure[Accessed:12/01/2016].

EuropeanCommission.(2016c).Funding.[Online]Availableat:https://ec.europa.eu/energy/en/funding-and-contracts[Accessed:11/01/2016].

EuropeanCommission.(2016d).EnergyEfficiency:Buildings.[Online]Availableat:https://ec.europa.eu/energy/en/topics/energy-efficiency/buildings[Accessed:20/01/2016].

EuropeanParliament,DirectorateGeneralforInternalPolicies.(2015).EnergyStorage:WhichMarketDesignsandRegulatoryIncentivesAreNeeded?Brussels,Belgium:EuropeanParliamentPublicationsoffice.

EuropeanSolarThermalIndustryFederation.(2016).SolarDistrictHeating.[Online]Availableat:http://www.estif.org/st_energy/technology/district_heating/[Accessed:11/01/2016].

Eurostat(2016a).ConsumptionofEnergy.[Online]Availableat:http://ec.europa.eu/eurostat/statistics-explained/index.php/Consumption_of_energy[Accessed:11/01/2016].

Eurostat(2016b).ElectricityProduction,ConsumptionandMarketOverview.[Online]Availableat:http://ec.europa.eu/eurostat/statistics-explained/index.php/Electricity_production,_consumption_and_market_overview#Electricity_generation[Accessed:26/01/2016].

Eurostat(2016c).ElectricityandHeatStatistics.[Online]Availableat:http://ec.europa.eu/eurostat/statistics-explained/index.php/Electricity_and_heat_statistics#Production_of_electricity[Accessed:11/01/2016].

Eurostat(2016d).GreenhouseGasEmissionStatistics.[Online]Availableat:http://ec.europa.eu/eurostat/statistics-explained/index.php/Greenhouse_gas_emission_statistics[Accessed:11/01/2016].

Evans,R.(2007).FuellingOurFuture:AnIntroductiontoSustainableEnergy.NewYork:CambridgeUniversityPress.

EWEA.(2015).WindinPower,2014.EuropeanStatistics.Brussels,Belgium:EWEA.

ExtremeTech(2016).Thisfullytransparentsolarcellcouldmakeeverywindowandscreenapowersource.[Online]Availableat:http://www.extremetech.com/extreme/188667-a-fully-transparent-solar-cell-that-could-make-every-window-and-screen-a-power-source[Accessed:20/01/2016].]

Farahani,H.,Wagiran,R.,&Hamidon,M.(2014).HumiditySensorsPrinciple,Mechanism,andFabrication

Technologies:AComprehensiveReview.Sensors,14(5):7881-7939.doi:10.3390/s140507881.

Ferreira,V.J.,Lopez-Sabiron,A.M.,Royo,P.,Aranda-Uson,A.andFerreira,G.(2015)Integrationofenvironmentalindicatorsintheoptimizationofindustrialenergymanagementusingphasechangematerials,EnergyConversionandManagement,104:67-77

Fehr,R.L.(2009).GuidetoBuildingEnergyEfficientHomesinKentuckyandMixedHumidClimateZone.Lexington:TheUniversityPressofKentucky.

FinkD.G.andWayneBeatyH.(2007).StandardHandbookforElectricalEngineers(15thEdition).NewYork:McGraw-Hill.



FreimarkB.(2006).SixWireSolution.Transmission&DistributionWorld.[Online]Availableat:http://tdworld.com/overhead-transmission/six-wire-solution[Accessed:11/12/2015].

GEODH(2016).Geothermaldistrictheating.[Online]Availableat:http://geodh.eu/about-geothermal-district-heating/[Accessed:11/01/2016].

Genus,A.,&Mafakheri,F.(2014).Aneo-institutionalperspectiveofsupplychainsandenergysecurity:BioenergyintheUK.AppliedEnergy,123,307–315.[Online]Availableat:http://doi.org/10.1016/j.apenergy.2014.01.084[Accessed:3/12/2015].

GlobalEnergyNetworkInstitute.(2016).ConcentratorPV:HarvestingMore,SpendingLess.[Online]Availableat:http://www.geni.org/globalenergy/library/technical-articles/generation/solar/renewableenergyworld.com/concentrator-pv-harvesting-more-spending-less/index.shtml[Accessed:7/01/2016].

Goetzler,W.(2007).VariableRefrigerantFlowSystems.ASHRAEJournal,April2007,pp.24-31.[Online]Availableat:http://docplayer.net/10557491-Variable-refrigerant-flow-systems.html[Accessed:11/01/2016].

Grainger,J.J.andStevensonW.D.Jr.(1994).PowerSystemAnalysisandDesign,(2ndEdition).NewYork:McGrawHill.

Grübler,A.(2012).Energytransitionsresearch:Insightsandcautionarytales.EnergyPolicy,50,8–16.doi:10.1016/j.enpol.2012.02.070

Guertler,B.andSpinler,S.(2015)Supplyriskinterrelationshipsandthederivationofkeysupplyriskindicators,TechnologicalForecasting&SocialChange,92:224-236

Gunaesekaran,A.,Patel,C.andMcGaughey,R.E.(2004)Aframeworkforsupplychainperformancemeasurement,InternationalJournalofProductionEconomics,87:333-347

Gunasekaran,A.,&Chung,W.W.C.(2004).Editorial:Specialissueonsupplychainmanagementforthe21stcenturyorganizationalcompetitiveness.Int.J.ProductionEconomics,87,209–212.[Online]Availableat:http://doi.org/10.1016/S0925-5273(03)00215-9[Accessed:7/12/2015]

Gunasekaran,A.,&Spalanzani,A.(2012).Sustainabilityofmanufacturingandservices :Investigationsforresearchandapplications.Intern.JournalofProductionEconomics,140(1),35–47.[Online]Availableat:http://doi.org/10.1016/j.ijpe.2011.05.011[Accessed:5/12/2015]

Gunasekaran,A.,Patel,C.,&Mcgaughey,R.E.(2004).Aframeworkforsupplychainperformancemeasurement.Int.J.ProductionEconomics,87,333–347.[Online]Availableat:http://doi.org/10.1016/j.ijpe.2003.08.003[Accessed:5/12/2015].

heatpumpcentre.org(n.a.).Energysources.[Online]Availableat:http://www.heatpumpcentre.org/en/aboutheatpumps/energysources/Sidor/default.aspx[Accessed:10/12/2015].

HighviewPower.(2016).Cryo-EnergySystem.[Online]Availableat:http://www.highview-power.com/[Accessed:11/01/2016].

Ho,A.(2015).TheEuropeanOffshoreWindIndustryKeyTrendsandStatistics1sthalf2015.Brussels,Belgium:EWEA.

Honorio,L.(2003).EfficiencyinElectricityGeneration.Brussels:EURELECTRIC“PreservationofResources”WorkingGroup’s“Upstream”Sub-GroupincollaborationwithVGB.

HsionLim,C.,&LoongLam,H.(2016).BiomasssupplychainoptimisationvianovelBiomassElementLifeCycleAnalysis(BELCA).AppliedEnergy,161,733–745.[Online]Availableat:http://doi.org/10.1016/j.apenergy.2015.07.030[Accessed:11/12/2015].

HydraTech.(2016).TechniquesfortheQuantificationofMethaneHydrateinEuropeanContinentalMargins.[Online]Availableat:http://www.hydratech.bham.ac.uk/[Accessed:11/01/2016].

ICCT.(2014).Europeanvehiclemarketstatistics,Pocketbook2014.[Online]Availableat:http://autotraveler.ru/en/spravka/fuel-price-in-europe.html#.Vp4ns1JYZSo[Accessed:11/01/2016].



Iddrisu,I.andBhattacharyya,S.C.(2015)SustainableEnergyDevelopmentIndex:Amulti-dimensionalindicatorformeasuringsustainableenergydevelopment,RenewableandSustainableEnergyReviews,50:513-530

IEA(2016).TechnologyRoadmap.Hydrogenandfuelcells.Paris,France:IEAPublications.

IEACleanCoalCentre.(n.d.).Pulverisedcoalcombustion.[Online]Availableat:http://www.iea-coal.org.uk/site/2010/database-section/ccts/pulverised-coal-combustion-pcc?[Accessed:11/12/2015].

IEA.(2008).CombinedHeatandPower,Evaluatingthebenefitsofgreaterglobalinvestment:Paris,France:IEAPublications.

IEA.(2012a).TechnologyRoadmap,BioenergyforHeatandPower.Paris,France:IEAPublications.

IEA.(2012b).TechnologyRoadmap,GeothermalHeatandPower.Paris,France:IEAPublications.

IEA.(2012c).EnergyTechnologyPerspective.Paris,France:IEAPublications.

IEA.(2012d).TechnologyRoadmap,SolarHeatingandCooling.Paris,France:IEAPublications.

IEA.(2013a).TechnologyRoadmap,Windenergy.Paris,France:IEAPublications.

IEA.(2013b).ThermalEnergyStorage.IEA-ETSAPandIRENATechnologyBrief,E17.Paris,France:IEAPublications.

IEA.(2013c).TechnologyRoadmap,Energy-efficientBuildings:HeatingandCoolingEquipment.Paris,France:IEAPublications.

IEA.(2013d).TechnologyRoadmap,SolarPhotovoltaicEnergy.Paris,France:IEAPublications.

IEA.(2016).Districtheating.[Online]Availableat:http://www.iea-dhc.org/the-technology.html[Accessed:30/01/2016].

IFLScience.(2015).SolarFuels:HowPlanesAndCarsCouldBePoweredByTheSun.[Online]Availableat:http://www.iflscience.com/technology/solar-fuels-how-planes-and-cars-could-be-powered-sun/[Accessed:30/11/2015].

Indiegogo.(2016).VortexBladeless:awindgeneratorwithoutblades.[Online]Availableat:https://www.indiegogo.com/projects/vortex-bladeless-a-wind-generator-without-blades--3#/[Accessed:30/01/2016].

INSEE.(n.d.).Internationalpricesofimportedrawmaterials–Heavyfueloil(Rotterdam)–PricesinUSdollarspertonne.[Online]Availableat:http://www.insee.fr/en/bases-de-donnees/bsweb/serie.asp?idbank=001642883[Accessed:28/11/2015].

InstituteforEnergyResearch.(2014).Overheadvs.Underground–Informationaboutburyinghigh-voltagetransmissionlines,Colorado’srenewableenergyfuture.ElectricityTransmission.

InternationalUnionofrailways.(2012).RailwayHandbook–EnergyConsumptionandCO2Emission.Paris,France:OECD/InternationalEnergyAgencyandtheInternationalUnionofRailways.

IPCC.(2014).Globalwarmingpotentialofselectedelectricitysources-AnnexII.[Online]Availableat:https://en.wikipedia.org/wiki/Life-cycle_greenhouse-gas_emissions_of_energy_sources#2014_IPCC.2C_Global_warming_potential_of_selected_electricity_sources[Accessed:30/11/2015].

Issu,I.I.,Pigosso,D.C.A.,McAloone,T.C.andRozenfield,H.(2015)Leadingproduct-relatedenvironmentalperformanceindicators:Aselectionguideanddatabase,JournalofCleanerProduction,Articleinpress

Jayalakshmi,M.,&Balasubramanian,K.(2008).SimpleCapacitorstoSupercapacitors.AnOverview.Hyderabad,India:Int.J.Electrochem.Sci.,3.

Jothilingam,D.,Suresh,G.(2015).Non-conventionalenergysourcessustainablepowergeneration.InternationalJournalofInnovativeResearchinTechnology,Science&Engineering(IJIRTSE).ISSN:2395-5619,Volume–1,Issue–3.May2015



Kagel,A.,&Bates,D.,&Gawell,K.(2007).AGuidetoGeothermalEnergyandtheEnvironment.Washington,D.C,USA:GeothermalEnergyAssociation.

Karangwa,E.(2008).EstimatingthecostofpipelinetransportationinCanada.PublishedonCanadianTransportationResearchForum.

Kempener,R.,&Neumann,F.(2014).TidalEnergy.Technologybrief.AbuDhabi,UnitedArabEmirates:InternationalRenewableEnergyAgency.

Kern,F.(2012).Usingthemulti-levelperspectiveonsocio-technicaltransitionstoassessinnovationpolicy.TechnologicalForecastingandSocialChange,(79),298–310.

Kerskes,H.,(2011).ThermalStorage:StateoftheArtandFutureAspects.RHCWorkshoponThermalEnergyStorage.Belgium,Brussels:workshoppresentation.

Kiefner,J.F.,&Rosenfeld,M.J.(2012).TheRoleofPipelineAgeinPipelineSafety.INGAAFoundationfinalreport.

Laird(2012).PVtechnologydevelopments2011andbeyond.[Online]Availableat:http://www.renewableenergyfocus.com/view/23695/pv-technology-developments-2011-and-beyond/[Accessed5/12/2015]

Lako,P.(2010).Coal-FiredPower.Paris,France:IEAETSAP.

Lazard.(2014).Lazard’slevelizedcostofEnergyanalysis-version8.0.(n.p.):LAZARD

Lee,J.H.(2014).Energysupplyplanningandsupplychainoptimizationunderuncertainty.JournalofProcessControl,24,323–331.[Online]Availableat:http://doi.org/10.1016/j.jprocont.2013.09.025[Accessed13/12/2015]

Lehtonen,M.(2013)Thenon-useandinfluenceofUKEnergySectorIndicators,EcologicalEconomics,35:24-34

Lexus.(2016).LexusCTcombinedcycledata.[Online]Availableat:http://www.lexus.it/car-models/ct/ct-200h/#Introduction[Accessed:30/11/2016].

May,G.,Barletta,I.,Stahl,B.andTaisch,M.(2015)Energymanagementinproduction:AnovelmethodtodevelopKeyPerformanceIndicatorsforimprovingenergyefficiency,AppliedEnergy,149:46-61

Marrero,T.R.(n.d.).Long-DistanceTransportofCoalbyCoalLogPipeline.CapsulePipelineResearchCenter,UniversityofMissouri.

MassachusettsInstituteofTechnology.(n.d.).Vibro-wind.[Online]Availableat:http://web.mit.edu/jociek/www/vibroWind.htm[Accessed:01/12/2015].

Meadowcroft,J.(2009).Whataboutthepolitics?Sustainabledevelopment,transitionmanagement,andlongtermenergytransitions.PolicySciences,42(4),323–340.

McKetta,A.n.d.CoalTransportation.UniversityofTexasDepartmentofChemicalEngineeringlectureNotes,Chapter4.

Microgreening(n.a.).CondensingBoilers..[Online]Availableat:http://www.microgreening.com/insulating-heating-and-cooling/condensing-boilers.php[Accessed:01/12/2015].

Miller,T.(2010).UnderstandingChillers:WhichisRightforYourApplication?[Online]Availableat:http://www.conairgroup.com/[Accessed:10/12/2015].

NationalInstituteofBuildingScience.(2016).High-PerformanceHVAC.[Online]Availableat:https://www.wbdg.org/resources/hvac.php[Accessed:10/01/2016].

NationalInstituteofBuildingScience.(2016).Website,NaturalVentilation.[Online]Availableat:https://www.wbdg.org/resources/naturalventilation.php[Accessed:10/01/2016].

NaturalGas.(2016).History.[Online]Availableat:http://naturalgas.org/overview/history/[Accessed:10/01/2016].



NavigantConsulting,Inc.(2012a).Life-CycleAssessmentofEnergyandEnvironmentalImpactsofLEDLightingProducts.(n.p.):U.S.DepartmentofEnergy.

NavigantConsulting,Inc.(2012b).Life-CycleEnergyConsumption:Incandescent,CompactFluorescent,andLEDLamps.(n.p.):U.S.DepartmentofEnergy.

Oberhofer,A.(2012).EnergyStorageTechnologies&TheirRoleinRenewableIntegration.GlobalEnergyNetworkInstitute.http://www.geni.org/globalenergy/research/energy-storage-technologies/Energy-Storage-Technologies.pdf[Accessed:01/12/2015].

Odesie.(n.d.).Boilerstypesandclassifications.[Online]Availableat:https://www.myodesie.com/wiki/index/returnEntry/id/3061[Accessed:01/12/2015].

Oellrich,L.R.(2004).NaturalGasHydratesandtheirPotentialforFutureEnergySupply.Karlsruhe,Germany:XVIINationalandVIISHMT/ASMEHeatandMassTransferConference,IGCAR,Kalpakkam,Jan.5-7,2004.

Okten,G.,&Kural,O.,&Algurkaplan,E.(2013).StorageofCoal:Problemsandprecautions.Istanbul,Turkey:Energystoragesystems–Vol.II,Encyclopediaoflifesupportsystems(EOLSS)

Olesen,B.W.(n.d).IndoorenvironmentalQualityrelatedtocomfort,healthandproductivity.Lyngby,Denmark:ICIEE.

OTA.(1978).CoalSlurryPipelineandUnitTrainSystems.[Online]Availableat:https://www.princeton.edu/~ota/disk3/1978/7817/781706.PDF[Accessed:10/01/2016].

Overholm,H.(2015).Spreadingtherooftoprevolution :Whatpoliciesenable.EnergyPolicy,84,69–79.http://doi.org/10.1016/j.enpol.2015.04.021

P.C.McKenzieCompany(n.a.).FiretubeorWatertube?What'sthedifference?.[Online]Availableat:http://www.mckenziecorp.com/boiler_tip_8.htm[Accessed:10/01/2016].

Park,J.(2013).ComparativeanalysisoftheVRFSystemandconventionalHVACSystems,focusedonlifecycle-cost.Atlanta,GA-USA:GeorgiaInstituteofTechnology.

PCMProductsLtd.(2016).PhaseChangeMaterials:ThermalManagementSolutions.[Online]Availableat:http://www.pcmproducts.net/[Accessed:21/01/2016].

PetroWiki.(2013).Oilstorage.[Online]Availableat:http://petrowiki.org/Oil_storage#Types_of_storage_tanks[Accessed:21/12/2015].

PICSSupplyChainCouncil.(2015).SCORFramework.[Online]Availableat:http://www.apics.org/sites/apics-supply-chain-council/frameworks/scor[Accessed:15/11/2015].

PortlandEnergyConservation.(2011).TheBuildingPerformanceTrackingHandbook.California:CaliforniaCommissioningCollaborative

PowerScoreCard.(2016).Electricityfromcoal.[Online]Availableat:http://powerscorecard.org/tech_detail.cfm?resource_id=2[Accessed:21/01/2016].

PöyryEnergyConsulting.(2009).Thepotentialandcostsofdistrictheatingnetworks.Oxford,UK:ReporttotheDepartmentofEnergyandClimateChange.

PPIAF.(2016).Railwayreform:toolkitforimprovingrailsectorperformance.[Online]Availableat:http://www.ppiaf.org/sites/ppiaf.org/files/documents/toolkits/railways_toolkit/download.html[Accessed:15/01/2016].

Quora.(2016).Howisasupercapacitordifferentfromacapacitor?[Online]Availableat:https://www.quora.com/How-is-a-supercapacitor-different-from-a-capacitor[Accessed:15/01/2016].

Radhakrishnane,Rm.(2012).Enhancingpowerplantproductivitythroughcoalstockyardmanagement.RSTPS



Renault.(2016).RenaultZoetechnicaldata.[Online]Availableat:https://www.renault.it/veicoli/gamma-ze.html?ORIGIN=SEM&CAMPAIGN=sem2015&gclid=CMyhxailuMoCFVQaGwodeqgBtA[Accessed:18/01/2016].

RenewableNorthwestProject.(2006).TidalenergylevelisedcostsfromNorthAmericanTidalIn-StreamEnergyConversionTechnologyFeasibilityStudy.EPRI,TP-008-NA.

RenewableNorthwest.(2009).Wave&TidalEnergyTechnology.[Online]Availableat:http://www.rnp.org/node/wave-tidal-energy-technology[Accessed:21/12/2015].

Rezaie,B.,&Rosen,M.A.(2012).Districtheatingandcooling:Reviewoftechnologyandpotentialenhancements.AppliedEnergy,93,pp.2–10.

Rip,A.,&Kemp,R.(1998).Technologicalchange.InHumanchoiceandclimatechange(pp.327–399).

RoburS.p.A.(2016).HeatPumpsComparison:basicprinciples.[Online]Availableat:http://www.robur.com/technical_dossiers/heat_pumps_absorption_technology/heat_pumps_comparison_basic_principles[Accessed:28/01/2016].

SandiaNationalLaboratories,(2016).AdvantagesofUsingMoltensalt.[Online]Availableat:http://www.webcitation.org/60AE7heEZ[Accessed:28/01/2016].

Searcy,C.,Karapetrovic,S.,&Mccartney,D.(2005).Designingsustainabledevelopmentindicators:analysisforacaseutility.MeasuringBusinessExcellence,9(2),33–41.[Online]Availableat:http://doi.org/10.1108/13683040510602867[Accessed:21/11/2015].

Seebregts,A.J.(2010).Gas-FiredPower.IEAETSAP-TechnologyBrief-E02.

Shahriar,S.,&Erkan,T.(2008).Whenwillfossilfuelreservesbediminished?.EnergyPolicy,1,pp.181-189.

Shahin,A.,&Mahbod,M.A.(2007).Prioritizationofkeyperformanceindicators.InternationalJournalofProductivityandPerformanceManagement,56(3),226–240.

Shepherd,C.,&Günter,H.(2006).Measuringsupplychainperformance:currentresearchandfuturedirections.JournalofProductivityandPerformanceManagement,55(3/4),242–258.

Simpson,G.,&Clifton,J.(2015).Theemperorandthecowboys :Theroleofgovernmentpolicyandindustryintheadoptionofdomesticsolarmicrogenerationsystems.EnergyPolicy,81,141–151.[Online]Availableat:http://doi.org/10.1016/j.enpol.2015.02.028[Accessed:23/11/2015].

Sivadasan,S.,Efstathiou,J.,Calinescu,A.,&HuacchoHuatuco,L.(2004).Supplychaincomplexity.InS.New&R.Westbrook(Eds.),UnderstandingSupplyChains(pp.133–163).Oxford:OxfordUniversityPress.

Smith,A.,Stirling,A.,&Berkhout,F.(2005).Thegovernanceofsustainablesocio-technicaltransitions.ResearchPolicy,34(10),1491–1510.doi:10.1016/j.respol.2005.07.005

Solomon,B.D.,&Krishna,K.(2011).Thecomingsustainableenergytransition:History,strategies,andoutlook.EnergyPolicy,39(11),7422–7431.doi:10.1016/j.enpol.2011.09.009

Slant/Fin.(2016).DifferencesbetweenBoilers&Furnaces.[Online]Availableat:http://www.slantfin.com/homeowners/difference-between-boiler-furnace.html[Accessed:28/01/2016].

SofregazUSInc.,&LRC.(1999).Commercialpotentialofnaturalgasstorageinlinedrockcaverns(LRC).TopicalReportSZUS-0005DE-AC26-97FT34348-01.

SolarReserve.(2016).MoltenSaltEnergyStorage.[Online]Availableat:http://www.solarreserve.com/en/technology/molten-salt-energy-storage[Accessed:28/01/2016].

SpiraxSarcoLimited.(2016).SteamAccumulators.[Online]Availableat:http://www.spiraxsarco.com/Resources/Pages/Steam-Engineering-Tutorials/the-boiler-house/steamaccumulators.aspx[Accessed:28/01/2016].

Staller,H.,&Tisch,A.(2010).Newtechnicalsolutionsforenergyefficientbuildings.SciNetwork-StateoftheArtreport.



Stank,T.P.,Dittmann,J.P.,&Autry,C.W.(2011).Thenewsupplychainagenda:asynopsisanddirectionsforfutureresearch.InternationalJournalofPhysicalDistribution&LogisticsManagement,41(10),940–955.

StratoSolar.(2016).GravityEnergyStorage.[Online]Availableat:http://www.stratosolar.com/gravity-energy-storage.html[Accessed:28/01/2016].

SuperPower.(2016).SuperconductingMagneticEnergyStorage(SMES).[Online]Availableat:http://www.superpower-inc.com/content/superconducting-magnetic-energy-storage-smes[Accessed:28/01/2016].

Tahir,S.,&Moulin,J.,&Coral,N.,&Uku,B.,&Posner,H.(2014).(PRO-LITE)Stateoftheart,Technicalreport.London,UK:IsleUtilities.

Taticchi,P.,Tonelli,F.,&Pasqualino,R.(2013).Performancemeasurementofsustainablesupplychains.InternationalJournalofProductivityandPerformanceManagement,62(8),782–804.

TheAssociationforDecentralisedEnergy.(2016).Whatiscombinedheatandpower?[Online]Availableat:http://www.theade.co.uk/what-is-combined-heat-and-power_15.html[Accessed:28/01/2016].

TheGreenAge.(2016).Mechanicalventilationinbuilding-whatyouneedtoknow.[Online]Availableat:http://www.thegreenage.co.uk/mechanical-ventilation-in-buildings-what-you-need-to-know/[Accessed:16/01/2016].

TheTelegraph.(2016).Gasometers:abriefhistory.[Online]Availableat:http://www.telegraph.co.uk/finance/newsbysector/energy/oilandgas/10473071/Gasometers-a-brief-history.html[Accessed:19/01/2016].

Thimsen,D.(2002),Stirlingengineassessment.Bellevue,WA.

Tidalpower.(2016).Tidalpower.[Online]Availableat:http://tidalpower.co.uk/[Accessed:12/01/2016].

Tidalpower.(n.d.).Tidalpower.[Online]Availableat:http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/Tidal%20Power.htm#streams[Accessed:16/01/2016].

Tomia.(2007).HydroelectricDam.WikipediaCommonsfile.[Online]Availableat:https://commons.wikimedia.org/wiki/File:Hydroelectric_dam.svg[Accessed:28/01/2016].

Trench,C.J.(2001).HowPipelinesMaketheOilMarketWork–TheirNetworks,OperationandRegulationNewYork:AllegroEnergyGroup.

UHIELE.(2016).LNGFrequentlyAskedQuestions.UniversityofHoustonInstituteforEnergyLaw&Enterprisepublication.

UnionofConcernedScientists.(2016).Coalpower:airpollution.[Online]Availableat:http://www.ucsusa.org/clean_energy/coalvswind/c02c.html#.Vp-4BfnhCM8[Accessed:19/01/2016].

UnionofConcernedScientists.(2016).Environmentalimpactofcoalpower:fuelsupply.[Online]Availableat:http://www.ucsusa.org/clean_energy/coalvswind/c02a.html#.Vp-4BfnhCM8[Accessed:19/01/2016].

UnionofConcernedScientists.(2016).EnvironmentalimpactofWindPower.[Online]Availableat:http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/environmental-impacts-wind-power.html#.VpJ8n_nhDIU[Accessed:21/01/2016].

UnionofConcernedScientists.(2016).EnvironmentalImpactsofRenewableEnergyTechnologies.[Online]Availableat:http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/environmental-impacts-of.html#.VpJ8hfnhDIU[Accessed:19/01/2016].

UOL-VENTILATION.(2016).Mechanicalforcedventilation.[Online]Availableat:http://uol-ventilation.weebly.com/mechanical.html[Accessed:21/01/2016].

USDept.ofEnergy.(2005).LiquefiedNaturalGas:UnderstandingtheBasicFacts.OfficeofFossilEnergypublication.



Vogel,R.,&Roberts,P.R.(1979).OperatingandMaintenanceCostsofUndergroundCollieryConveyorsEnvironmentalandPollutionAspectsofCoalSlurryPipelines.EnvironmentalProtectionAgencyTechnicalReport

VV.AA.(2006).MicroCHPsystems:state-of-the-art.GreenLodgesProject-Technicalreport.

VV.AA.(2009a).LifetimeofWhiteLEDs.USDepartmentofenergy-BuildingTechnologiesProgram.

VV.AA.(2009b).NaturalVentilationforInfectionControlinHealth-CareSettings.WHOpublications/guidelines.

VV.AA.(2010).BuildingPerformanceTrackinginLarge-CommercialBuildings:ToolsandStrategies.BuildingCommissioning:StrategiesandTechnologies–TechnicalReport.

VV.AA.(2010).VRV/VRFVariablerefrigerantvolume(orflow)technology.AirConditioningandHeatPumpInstitutepublication.

VV.AA.(2010).WholeBuildingDesignGuide,FederalGreenConstructionGuideforSpecifiers.[Online]Availableat:http://fedgreenspecs.wbdg.org[Accessed:21/01/2016].

VV.AA.(2011a).Leagevolazionifiscaliperilrisparmioenergetico.AgenziadelleEntrate–Handbook.

VV.AA.(2012a).BestavailabletechnologiesfortheheatandcoolingmarketintheEuropeanUnion.JRCScientificandPolicyReports.

VV.AA.(2012b).Evaluatingenergystorageoptions:acasestudyatLosAngelesHarborcollege.DonaldBrenSchool-ProjectReport.

VV.AA.(2012c).Direttiva2012/27/UEdelParlamentoEuropeoedelConsigliodel25ottobre2012sull'efficienzaenergetica,chemodificaledirettive2009/125/CEe2010/30/UEeabrogaledirettive2004/8/CEe2006/32/CE.Gazzettaufficialedell’UnioneeuropeaL315/51.

VV.AA.(2013a).GridEnergyStorage.U.S.DepartmentofEnergyreport.

VV.AA.(2013b).ThepowersectorinPhase2oftheEUETS:fewerCO2emissionsbutjustasmuchcoal.CDCClimateReport,42.

VV.AA.(2013c).ThermalEnergyStorage.IEA-ETSAPandIRENATechnologyBrief,E17.

VV.AA.(2014a).EnergyinTransport.SustainableEnergyAuthorityofIreland,2014Report.

VV.AA.(2014b).MarketObservatoryforEnergy.QuarterlyReportonEuropeanElectricityMarkets,7.

VV.AA.(2015a).OverviewofpurchaseandtaxincentivesforelectricvehiclesintheEUin2015.ACEApublications.

VV.AA.(2015b).ImprovementofEnergyEfficiencyinTechnologyParksoftheMedAreathroughIntelligentModelsandUses.SmartMEDParks.Which.(2016).Petrolvsdieselbuyingguide.[Online]Availableat:http://www.which.co.uk/cars/choosing-a-car/buying-a-car/petrol-or-diesel/petrol-vs-diesel-buying-guide/[Accessed:21/01/2016].

VV.AA.(2004).Finalreportontechnicaldata,costsandlifecycleinventoriesofadvancedfossilpowergenerationsystems.NEEDSProjectTechnicalReport.

VV.AA.(2011b).L’efficienzanelsettoredelleretienergetiche.ENEApublications

VV.AA.(2011c)IPCC:SpecialReportonRenewableEnergySourcesandClimateChangeMitigation

Wagner,M.,&Schaltegger,S.(2004).TheEffectofCorporateEnvironmentalStrategyChoiceandEnvironmentalPerformanceonCompetitivenessandEconomicPerformance :AnEmpiricalStudyofEUManufacturing.EuropeanManagementJournal,22(5),557–572.[Online]Availableat:http://doi.org/10.1016/j.emj.2004.09.013[Accessed:25/11/2015].

Wee,H.,Yang,W.,Chou,C.,&Padilan,M.V.(2012).Renewableenergysupplychains,performance,applicationbarriers,andstrategiesforfurtherdevelopment.RenewableandSustainableEnergyReviews,16(8),5451–5465.[Online]Availableat:http://doi.org/10.1016/j.rser.2012.06.006[Accessed:21/11/2015].



WorldNuclearAssociation.(2016).NuclearpowerinEuropeanUnion.[Online]Availableat:http://www.world-nuclear.org/info/Country-Profiles/Others/European-Union/[Accessed:21/01/2016].

WorldwatchInstitute(2012).UseandCapacityofGlobalHydropowerIncreases[Online]Availableat:http://www.worldwatch.org/node/9527[Accessed:21/01/2016].

Wüstemeyer,C.,Madlener,R.,&Bunn,D.W.(2015).Astakeholderanalysisofdivergentsupply-chaintrendsfortheEuropeanonshoreandoffshorewindinstallations.EnergyPolicy,80,36–44.[Online]Availableat:http://doi.org/10.1016/j.enpol.2015.01.017[Accessed:20/11/2015].

Xuequa,M.(2015).ThreeGorgesbreaksworldrecordforhydropowergeneration.[Online]Availableat:http://news.xinhuanet.com/english/china/2015-01/01/c_127352471.htm[Accessed10/12/2015].

Yu,H.(2015).GlobalLEDLightingTrendsRevealSignificantGrowthandProductDevelopment.[Online]Availableat:http://www.ledjournal.com/main/blogs/global-led-lighting-trends-reveal-significant-growth-and-product-development/[Accessed18/12/2015].

Zhao,C.,&Chen,B.(2014).China’soilsecurityfromthesupplychainperspective:Areview.AppliedEnergy,136,269–279.[Online]Availableat:http://doi.org/10.1016/j.apenergy.2014.09.01[Accessed:23/11/2015].

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