Gesamtverband der Deutschen Versicherungswirtschaft e. V.

Renewable energies

Overall survey of Engineering Insurers within the German Insurance Association (GDV) on the level of technological development and the technical hazard potential

Status: March 2010

Gesamtverband der Deutschen Versicherungswirtschaft e. V. (GDV)(German Insurance Association)

Wilhelmstrasse 43 / 43 G, 10117 Berlin, GermanyPostfach 08 02 64, 10002 Berlin, Germany

phone +49/30/20 20-50 00, fax +49/30/20 20-60 00berlin@gdv.de, www.gdv.de

7. Edition Re

new

able energies 20

10G

DV

The authors have exercised the greatest care in drawing up the text and illustrations. Although the sources were verified to the best of our knowledge and belief, faults cannot be completely excluded. Consequently, neither the authors nor the publishing house accept any legal respon-sibility, nor any guarantee for the information and illustrations, either explicitly or unspoken, regarding quality, implementation or usability for a given purpose.

Cover picture: Fotolia

Back page: Fotolia

Renewable energies

Overall survey of Engineering Insurers within the German Insurance Association (GDV) on the level of technological development and the technical hazard potential

Status: March 2010

Imprint:

Editorial status:

26.05.2010

Publisher:

Gesamtverband der Deutschen Versicherungswirtschaft e. V. (GDV)

(German Insurance Association)

Responsible:

Commission of Engineering Insurers

Editor:

Thorsten Land

GDV

Wilhelmstrasse 43/43 G

10117 Berlin, Germany

phone: +49 / 30 / 2020 - 5341

fax: +49 / 30 / 2020 - 6341

berlin@gdv.de

www.gdv.de

Translation and editorial office:

Martina Wrzburg / Christine Rdisch

ISBN:

978-3-939163-32-9

Protective fee:

17.50

CONTENTS

II Introduction - Renewable Energies

I Foreword

III Wind Power

IV Solar Energy Systems

V Biomass

VI Biogenic fuels

VII Biogas

VIII Fuel Cell and Hydrogen Technology

IX Geothermics

X CO2 capture, transport and Storage

XI Glossary

23

27

43

145

179

209

277

309

229

329

361

COOPERATORS

Michael Graf Munich

Peter Bender Munich

Prof. Dr. Dr. Peter Hppe Munich

Thorsten Land (editor) Berlin

Jrg Michaels Hanover

Dietrich-Uwe Oppers Dusseldorf

Jan Pohl Munich

Manfred Schfer Bremen

Contents 5

Contents

I Foreword

II Introduction Renewable Energies

1 Introduction ..................................................................................................................................................... 29

2 The Aims of the Federal German Government ............................................................................................... 30

3 Technical Survey (Overall and by Sources of Energy) ..................................................................................... 31

3.1 Water power ....................................................................................................................................................... 31

3.2 Wind power .......................................................................................................................................................... 31

3.3 Solar energy ......................................................................................................................................................... 33

3.3.1 Solar collectors .................................................................................................................................. 33

3.3.2 Photovoltaic installations .............................................................................................................. 33

3.3.3 Solar thermal energy ....................................................................................................................... 34

3.4 Biomasse, Biogas ............................................................................................................................................... 34

3.5 Fuel cells and hydrogen energy ....................................................................................................................... 35

3.6 Geothermics ......................................................................................................................................................... 35

4 Special Technologies ........................................................................................................................................ 36

4.1 Solar chimneys .................................................................................................................................................... 36

4.2 Tidal, wave and marine-current power ......................................................................................................... 37

4.2.1 Tidal power stations ........................................................................................................................ 37

4.2.2 Wave power stations ....................................................................................................................... 38

4.2.3 Floating Turbines .............................................................................................................................. 39

4.2.4 Osmosis power stations ................................................................................................................. 40

5 Sources and Internet Addresses ...................................................................................................................... 40

6 Contents

III Wind Power

1 Introduction ..................................................................................................................................................... 45

2 Basic differences between installation concepts ........................................................................................... 45

2.1 Wind power generators with a gearbox and rapidly rotating output shaft ....................................... 45

2.2 Wind power generators with a gearbox and slowly rotating output shaft ........................................ 46

2.3 Wind power generators without a gearbox ................................................................................................ 46

3 Components ..................................................................................................................................................... 47

3.1 Foundation ........................................................................................................................................................... 47

3.2 Tower ..................................................................................................................................................................... 47

3.3 Chassis/Nacelle ................................................................................................................................................... 48

3.4 Nacelle guiding system (azimuth drive) ....................................................................................................... 49

3.5 Rotor hub .............................................................................................................................................................. 49

3.6 Rotor ....................................................................................................................................................................... 49

3.7 Main bearing ........................................................................................................................................................ 49

3.8 Main shaft (also rotor shaft) ............................................................................................................................ 50

3.9 Main gearbox ....................................................................................................................................................... 50

3.9.1 Load distribution gearbox .............................................................................................................. 50

3.9.2 Transmission concept for a constant output rotating speed without a converter ......... 51

3.10 Hydraulic system ................................................................................................................................................ 52

3.11 Brakes..................................................................................................................................................................... 52

3.12 Generator .............................................................................................................................................................. 52

3.13 Electrical installation ......................................................................................................................................... 53

3.14 Interconnecting station .................................................................................................................................... 54

3.15 Distribution of value within a wind turbine ................................................................................................ 54

4 Operating safety .............................................................................................................................................. 54

4.1 Maintenance ........................................................................................................................................................ 54

4.2 Lightning protection for wind turbines ........................................................................................................ 54

4.3 Fire protection systems ..................................................................................................................................... 56

4.4 Braking systems .................................................................................................................................................. 56

4.5 Condition Monitoring ........................................................................................................................................ 56

4.6 Oil particle count ................................................................................................................................................ 57

5 State of the Art ................................................................................................................................................. 57

5.1 Land-based wind farms ..................................................................................................................................... 57

5.2 Offshore wind farms .......................................................................................................................................... 58

Contents 7

6 Damage potential ............................................................................................................................................ 58

6.1 Normal external conditions ............................................................................................................................ 59

6.2 Abnormal external conditions ....................................................................................................................... 59

6.3 Normal internal conditions .............................................................................................................................. 59

6.4 Abnormal internal conditions ......................................................................................................................... 59

6.5 Other conditions ................................................................................................................................................. 59

7 Damage scenarios ............................................................................................................................................ 60

7.1 Onshore wind turbines ..................................................................................................................................... 60

7.1.1 Rotor blades ....................................................................................................................................... 60

7.1.2 Gearbox and main rotor bearing ................................................................................................. 61

7.1.3 Generator ........................................................................................................................................... 63

7.1.4 Electrical equipment ....................................................................................................................... 63

7.1.5 Foundations ....................................................................................................................................... 65

7.1.6 Total loss ............................................................................................................................................. 66

7.2 Offshore wind farms .......................................................................................................................................... 66

8 Risk of operating interruptions ....................................................................................................................... 66

8.1 Risk increasing factors ....................................................................................................................................... 67

8.2 Remuneration rates in conformity with the Renewable Energy Sources Act, ........................................

dated 21st July 2004 (EEG 2004) and 25th October 2008 (EEG 2009) ..................................................... 67

8.3 Current yields, efficiency................................................................................................................................... 71

8.4 Damage assessment due to machine operation interruptions .............................................................. 71

8.5 Service agreements ............................................................................................................................................ 73

Attachment 1 Technical Note VdS 891 Wind Farms at Sea (Offshore Wind Farms)

1 Foreword relating to the 1st edition (March 2007) ......................................................................................... 75

2 Introduction ..................................................................................................................................................... 78

2.1 Planning status ................................................................................................................................................... 78

2.2 Approvals status.................................................................................................................................................. 78

2.3 State support ....................................................................................................................................................... 80

2.4 Foundation Offshore Wind Energy ................................................................................................................. 80

2.5 Research platforms FINO 1, 2 and 3 ............................................................................................................... 81

3 State of the art ............................................................................................................................................... 81

3.1 Installation technology ..................................................................................................................................... 81

3.2 Foundations and bases ..................................................................................................................................... 84

3.3 Submarine cables and land connection ........................................................................................................ 88

3.3.1 Power grid .......................................................................................................................................... 89

3.3.2 Transformer substation .................................................................................................................. 89

8 Contents

4 Construction ..................................................................................................................................................... 91

5 Operation.......................................................................................................................................................... 93

5.1 Wind farm monitoring ...................................................................................................................................... 93

5.2 Maintenance and repair.................................................................................................................................... 93

5.3 Fire protection ..................................................................................................................................................... 94

5.4 Applicable standards and guidelines (guest contribution by Germanischer Lloyd, Hamburg) ...... 94

6 Damage potential and scenario ..................................................................................................................... 95

6.1 Damage potential .............................................................................................................................................. 95

6.2 Damage scenario ................................................................................................................................................ 95

7 Insurability ....................................................................................................................................................... 97

7.1 Elementary risks .................................................................................................................................................. 97

7.1.1 Wind, waves and tides ................................................................................................................... 97

7.1.2 Hail ....................................................................................................................................................... 97

7.1.3 Ice motion .......................................................................................................................................... 97

7.1.4 Ice formation ..................................................................................................................................... 98

7.1.5 Lightning ............................................................................................................................................ 98

7.1.6 Earthquakes ....................................................................................................................................... 98

7.1.7 Tsunami .............................................................................................................................................. 98

7.2 The risks of operating interruptions .............................................................................................................. 99

7.3 Internal damage (Manufacturers warranty) .............................................................................................100

7.4 Liability risks .......................................................................................................................................................101

7.5 Transport risks (marine hull insurance) ......................................................................................................102

7.6 Accumulation control ......................................................................................................................................103

Attachment 1.1 .........................................................................................................................................................104

Attachment 1.2 .........................................................................................................................................................105

Attachment 1.3 .........................................................................................................................................................106

1 Limit of indemnity .........................................................................................................................................106

2 Insured objects ...............................................................................................................................................106

3 Coverage for additional costs ........................................................................................................................107

3.1 The costs for averting and reducing damage ............................................................................................107

3.2 Additional work to reposition a section of the installation ...................................................................107

3.3 Removal of wrecks, wreck parts and/or offshore debris .........................................................................107

3.4 Standby costs (deployment costs) ................................................................................................................107

3.5 Offshore cancellation costs ............................................................................................................................108

3.6 Cost of establishing the cause of the damage ..........................................................................................108

Contents 9

3.7 Endangering the environment ......................................................................................................................108

3.8 The cost of further transport .........................................................................................................................108

4 Warranty Surveyor .........................................................................................................................................109

5 Miscellaneous conditions ..............................................................................................................................111

5.1 Foundations .......................................................................................................................................................111

5.2 Directional horizontal drilling .......................................................................................................................111

Attachment 2 VdS 3523 fire protection for Wind turbines (WEA)

1 Introductory remarks .....................................................................................................................................113

2 Range of application ....................................................................................................................................113

3 Risks ................................................................................................................................................................114

3.1 Material damage and consequential damage ..........................................................................................114

3.1.1 Material damage risk ....................................................................................................................114

3.1.2 Exposure to operating interruptions .........................................................................................115

3.2 Damage examples ............................................................................................................................................115

3.2.1 Fire damage due to lightning ......................................................................................................115

3.2.2 Fire damage due to machine breakdown ................................................................................116

3.2.3 Fire damage due to faults in the electrical equipment ........................................................117

3.2.4 Fire damage due to electrical oscillating circuits ...................................................................117

3.3 Fire damage causes ..........................................................................................................................................117

3.3.1 Heightened risk of fire due to lightning ...................................................................................118

3.3.2 Electrical installation.....................................................................................................................118

3.3.3 Hot surfaces ....................................................................................................................................118

3.3.4 Fire hazardous work ......................................................................................................................118

3.3.5 Fire load ...........................................................................................................................................118

3.3.6 Significantly restricted access for fire fighting .......................................................................119

3.3.7 Maintenance limitations (maintenance, inspection, repair) ..............................................119

4 Protection aims and protection concept ......................................................................................................119

5 Protection measures ......................................................................................................................................121

5.1 Diminishing the risk of fires ...........................................................................................................................121

5.1.1 Lightning and surge-current protection ..................................................................................121

5.1.2 Minimizing the risks associated with electrical equipment ..............................................122

5.1.3 Minimizing combustible substances ........................................................................................122

5.1.4 Avoiding possible sources of ignition ......................................................................................123

5.1.5 Fire hazardous work ......................................................................................................................123

5.1.6 Servicing (maintenance, inspection and repair) machines and

electrical installations ..................................................................................................................123

5.1.7 Smoking prohibition .....................................................................................................................125

5.1.8 Training ............................................................................................................................................125

10 Contents

5.2 Fire detection and fire fighting .....................................................................................................................125

5.2.1 Fire detection ..................................................................................................................................126

5.2.2 Fire fighting .....................................................................................................................................127

5.2.3 Monitoring faults ...........................................................................................................................130

5.2.4 Closing down safety devices .......................................................................................................130

5.3 Damage limitation measures ........................................................................................................................130

5.4 Quality assurance .............................................................................................................................................131

6 Literature / Sources ........................................................................................................................................131

Attachment 3 Technical Attachment

1 Rules and quality criteria to erect prefabricated stations ...........................................................................135

1.1 Introduction .......................................................................................................................................................135

1.2 General remarks ................................................................................................................................................135

2 Erecting the station ........................................................................................................................................135

2.1 Type approval tests ...........................................................................................................................................135

2.2 Tests to establish the heating of the principal parts of a station (heating tests) ............................135

2.3 Arcing fault testing ..........................................................................................................................................135

3 Documentation / Test Protocols ....................................................................................................................136

4 Minimum requirements expected of the station equipment .....................................................................136

4.1 Building ...............................................................................................................................................................136

4.2 Medium-voltage switching station .............................................................................................................136

4.3 Three-phase oil transformer ..........................................................................................................................137

4.4 Low-voltage distribution ................................................................................................................................137

4.5 Station-internal cabling ..................................................................................................................................137

4.6 Earthing system ................................................................................................................................................137

4.7 Over-voltage protection/ Lightning conductor .........................................................................................137

4.8 Protection of equipment ................................................................................................................................138

5 Service .............................................................................................................................................................138

Attachment 4 Requirements Expected of Condition Monitoring Systems for Wind Turbines

1 Guideline for the Certification of Condition Monitoring Systems for Wind Turbines ..............................139

1.1 Introduction ......................................................................................................................................................139

1.2 Background .......................................................................................................................................................140

1.3 Condition Monitoring System ......................................................................................................................140

1.3.1 Guideline for the certification of condition monitoring systems for wind turbines ...140

1.3.2 Condition Monitoring System ....................................................................................................141

Contents 11

1.3.3 Requirements expected of wind turbine manufacturers ....................................................143

1.3.4 Requirements expected of the monitoring centre ................................................................143

1.4 Summary.............................................................................................................................................................144

1.5 Literature ............................................................................................................................................................144

IV Solar Energy Systems

1 Introduction ...................................................................................................................................................147

2 Photovoltaics: Cells and panels ....................................................................................................................147

2.1 Customary distinctions ..................................................................................................................................148

2.2 Dimensions ........................................................................................................................................................148

2.3 Laminate panels ................................................................................................................................................149

2.4 Concentrator Photovoltaic System ...............................................................................................................149

2.5 Photo thermics (PVT) .......................................................................................................................................149

2.6 Tube collectors ...................................................................................................................................................149

2.7 Transparent panels ...........................................................................................................................................150

2.8 Building integrated PV (GIPV) ........................................................................................................................150

2.9 Customary cell materials and their abbreviated designations .............................................................152

2.10 Performance loss due to ageing (degradation) .........................................................................................152

2.11 Edge and back sealing .....................................................................................................................................153

2.12 Hot Spots ............................................................................................................................................................153

2.13 Delamination .....................................................................................................................................................153

2.14 Panel frames ......................................................................................................................................................153

2.15 Panel terminal boxes and cable outlets ......................................................................................................154

2.16 Plug connectors .................................................................................................................................................154

2.17 Generator terminal box ..................................................................................................................................155

2.18 Testing and safety standards .........................................................................................................................155

2.19 Hail test ...............................................................................................................................................................157

3 Power inverter ................................................................................................................................................157

3.1 Inverter with a transformer ...........................................................................................................................158

3.2 Inverter without a transformer .....................................................................................................................158

3.3 Additional functions ........................................................................................................................................158

3.4 Panel inverter .....................................................................................................................................................158

3.5 Installation rules ...............................................................................................................................................158

3.6 Inverter reliability .............................................................................................................................................159

12 Contents

4 Solar Mounting Systems ................................................................................................................................160

4.1 Influences and loads ........................................................................................................................................160

4.2 Tracking systems ...............................................................................................................................................160

4.2.1 Single-Axis-Tracking .....................................................................................................................161

4.2.2 Dual-Axis-Tracker ...........................................................................................................................161

4.3 Storm safety .......................................................................................................................................................161

4.4 Facade installations .........................................................................................................................................162

5 Proof of stability (statics)...............................................................................................................................162

6 Cables ..............................................................................................................................................................163

7 Lightning and overvoltage ............................................................................................................................163

7.1 External lightning protection ........................................................................................................................163

7.2 Internal lightning protection .........................................................................................................................163

7.3 Standards for lightning protection installations ......................................................................................165

7.4 Literature relating to lightning protection .................................................................................................165

8 Damage ..........................................................................................................................................................165

8.1 Lighting and overvoltage damage ................................................................................................................165

8.2 Damage frequency and profile associated with photovoltaic installations......................................166

8.3 Marten and rodent damage ..........................................................................................................................167

8.4 Environmental pollution .................................................................................................................................167

9 Business Interruption.....................................................................................................................................167

9.1 Business Interruption ......................................................................................................................................168

9.2 Earnings forecasts ............................................................................................................................................168

9.3 Data of Global Irradiation ...............................................................................................................................168

9.4 Data sources .......................................................................................................................................................169

9.5 Performance Ratio ............................................................................................................................................169

10 Remuneration rates 2010 .............................................................................................................................170

11 Thermal solar systems and solar power plants ............................................................................................170

11.1 Solar power stations ........................................................................................................................................170

11.2 Small scale installations .................................................................................................................................170

11.2.1 Principal parts of a solar collector..............................................................................................170

11.2.1.1 Flat-plate collector ................................................................................................170

11.2.1.2 Vacuum-tube collector ........................................................................................171

11.2.1.3 Hot-water heat accumulator .............................................................................171

11.2.1.4 Heat exchanger......................................................................................................171

11.2.1.5 Measuring and control system ..........................................................................171

11.2.1.6 Air collectors ...........................................................................................................171

11.3 Solar power stations ........................................................................................................................................171

Contents 13

11.3.1 Solar power stations with concentrated solar power (CSP) ..............................................171

11.3.1.1 Parabolic trough power station - Degradation of the receiver ..................172

11.3.1.2 Fresnel solar power station ................................................................................173

11.3.1.3 Solar tower power stations ................................................................................173

11.3.1.4 Parabolic reflector power station (Dish-Stirling system) ............................174

11.3.1.5 Solar chimney power station .............................................................................175

11.3.2 Solar heat power stations without concentration and solar pond power stations ......175

12 GDV Publications ...........................................................................................................................................176

13 Internet addresses .........................................................................................................................................177

V Biomass

1 Fundamentals ................................................................................................................................................181

1.1 Biogenic fuels.....................................................................................................................................................181

1.2 Woody biomass .................................................................................................................................................181

1.3 Energy plants .....................................................................................................................................................181

2 Biomass properties ........................................................................................................................................182

3 Processing, storage and transport ................................................................................................................183

3.1 Solid biomass .....................................................................................................................................................183

3.2 Liquid bioenergy carriers ................................................................................................................................185

4 Energetic use ..................................................................................................................................................185

4.1 Heat from solid biomass .................................................................................................................................185

4.1.1 Firing techniques ............................................................................................................................186

4.1.2 Thermochemical gasification .....................................................................................................189

4.1.3 Heat and power ..............................................................................................................................197

4.1.4 Liquefaction of solid biomass (pyrolysis) .................................................................................199

5 Relevant statutory framework conditions ...................................................................................................199

5.1 General aspects for approval .........................................................................................................................199

5.2 The German Biomass Ordinance ..................................................................................................................201

5.3 Waste Wood Ordinance ..................................................................................................................................202

5.4 European Standard for Biomass Solid Fuels Wood chip classes in .............................................................

keeping with prCEN/TS 14961 ......................................................................................................................203

5.5 Wood pellets in keeping with DIN 51731...................................................................................................204

6 Damage potential ..........................................................................................................................................205

7 Damage caused by interrupted operation ...................................................................................................205

8 Damage experience .......................................................................................................................................206

14 Contents

9 Prospects ........................................................................................................................................................206

10 Codes of Practice and Regulations ................................................................................................................206

11 Sources and Internet Addresses ....................................................................................................................207

VI Biogenic fuels

1 Fundamentals ................................................................................................................................................211

1.1 Types of fuel .......................................................................................................................................................211

1.2 Vegetable oil as fuel .........................................................................................................................................212

2 Properties of vegetable oils ...........................................................................................................................212

3 Production ......................................................................................................................................................213

3.1 Production comparison between biodiesels and vegetable oil ............................................................213

3.2 Preparation ........................................................................................................................................................213

3.3 Usability ..............................................................................................................................................................213

3.4 Peculiarities ........................................................................................................................................................214

4 Engine technology .........................................................................................................................................214

4.1 Combustion process in the diesel engine ...................................................................................................214

4.1.1 Precombustion chamber process ...............................................................................................215

4.1.2 Swirl-chamber process .................................................................................................................215

4.1.3 Direct injection ...............................................................................................................................215

4.2 Change-over .......................................................................................................................................................216

5 Framework conditions ...................................................................................................................................216

5.1 Directive 2003/30/EG ......................................................................................................................................216

5.2 Standardisation .................................................................................................................................................217

5.3 Draft Quality Standard E DIN 51605............................................................................................................217

6 Operating experiences ...................................................................................................................................218

6.1 Stationary operation (BHKW - Cogeneration) ...........................................................................................218

6.2 Mobile operation ..............................................................................................................................................220

6.3 100 Tractors Demonstration Project ............................................................................................................220

7 Damage/Losses caused by interruptions......................................................................................................221

8 Damage/Loss experience ..............................................................................................................................222

9 Damage/Loss prevention ..............................................................................................................................225

Contents 15

10 Prospects ........................................................................................................................................................226

10.1 Vegetable oil fuelling in stationary operation ..........................................................................................226

10.2 Vegetable oil fuelling in mobile operation .................................................................................................226

11 Codes and regulations ...................................................................................................................................227

12 Sources and Internet addresses ....................................................................................................................227

VII Biogas

1 Basic information ...........................................................................................................................................231

1.1 Microbiology and biochemistry of fermentation .....................................................................................231

1.2 Single-phase method.......................................................................................................................................231

1.3 Two-phase method ..........................................................................................................................................232

1.4 Properties of biogas .........................................................................................................................................232

2 Plant engineering ...........................................................................................................................................233

2.1 Single-stage mesophilic method ..................................................................................................................233

2.2 Two-stage mesophilic method with horizontal concrete fermenter .................................................234

2.3 Two-stage mesophilic or thermophilic process with horizontal steel fermenter ............................235

2.4 Mesophilic method with two fermenters connected in series ............................................................236

2.5 Two-stage mesophilic method with integrated sanitation ...................................................................237

2.6 Three-stage thermophilic method with possible sanitation ................................................................238

2.7 Dry fermentation ..............................................................................................................................................239

2.8 Batch method ....................................................................................................................................................240

3 Substrate preparation ...................................................................................................................................241

3.1 Sand .....................................................................................................................................................................241

3.2 Sanitation ...........................................................................................................................................................241

3.3 Fermenter ...........................................................................................................................................................241

3.4 Co-fermentation ...............................................................................................................................................241

3.5 Temperatures .....................................................................................................................................................241

3.6 Retention time ..................................................................................................................................................241

3.7 Degree of decompositon ................................................................................................................................241

3.8 Sonication (CH4 booster) ..............................................................................................................................242

3.9 Dry matter content...........................................................................................................................................242

3.10 Disturbances in biology .................................................................................................................................242

3.11 Mixing method ..................................................................................................................................................243

3.12 Gas tank, pipes and valves .............................................................................................................................244

16 Contents

3.13 Safety equipment for gas tanks ....................................................................................................................245

3.14 Cement tank in biogas plants ........................................................................................................................245

3.15 Process control ...................................................................................................................................................246

3.16 Gas analysis ........................................................................................................................................................246

4 Biogas processing ...........................................................................................................................................246

4.1 Gas purification .................................................................................................................................................246

4.2 Hydrogen sulphide ...........................................................................................................................................247

4.3 Desulphurisation method ..............................................................................................................................247

4.3.1 Organic desulphurisation (desulphurisation by supplying air) ..........................................247

4.3.2 Biofilter, bioscrubber and trickling filter plants .....................................................................248

4.3.3 Iron hydroxide .................................................................................................................................249

4.3.4 Iron (II) sulphate ............................................................................................................................249

4.3.5 External chemical desulphurisation..........................................................................................249

5 Biogas supply .................................................................................................................................................249

5.1 Process steps ......................................................................................................................................................250

5.2 Gas requirements .............................................................................................................................................250

5.3 Methane accumulation / carbon dioxide capture and storage ............................................................251

5.3.1 Pressure wash .................................................................................................................................251

5.3.2 Pressure swing method ................................................................................................................251

5.3.3 Membrane separation process ...................................................................................................252

5.3.4 Overview of the carbon dioxide capture and storage method ..........................................252

5.4 Siloxanes ............................................................................................................................................................252

5.5 Other methods of gas extraction .................................................................................................................253

5.5.1 Pit gas ................................................................................................................................................253

5.5.2 Landfill gas .......................................................................................................................................253

5.5.3 Digester gas .....................................................................................................................................253

5.5.4 Hydrogen gas .................................................................................................................................254

5.6 Renewable Energies Law (EEG, 2009) ..........................................................................................................254

5.7 Renewable Energies Heat Law (EEWrmeG) ..............................................................................................255

6 Combined heat and power (CHP) generation ...............................................................................................255

6.1 Engine-based combined power and heat cogenerating station (BHKW) ..........................................255

6.2 Micro gas turbine ..............................................................................................................................................256

6.3 Fuel cells ..............................................................................................................................................................256

6.4 Engine-based cogeneration stations ...........................................................................................................257

6.4.1 Pilot injection engine ....................................................................................................................258

6.4.2 Gas internal combustion engine ................................................................................................259

7 Smart Grid (or power supply networks that show some initiative) ...........................................................260

8 Corrosion ........................................................................................................................................................262

Contents 17

9 Losses due to interruption .............................................................................................................................262

10 Safety rules for agricultural biogas plants ....................................................................................................263

10.1 Dangers and risks .............................................................................................................................................263

10.2 Fire protection ...................................................................................................................................................264

10.3 Lightning and overvoltage protection ........................................................................................................266

10.4 GDV publications ..............................................................................................................................................266

11 Quality criteria for biogas plants as per VDI 4631 ......................................................................................266

12 Prevention ......................................................................................................................................................267

12.1 Maintenance contract .....................................................................................................................................267

12.2 Revisions .............................................................................................................................................................267

12.3 Thermography ...................................................................................................................................................267

13 Experiences of damage ..................................................................................................................................267

13.1 Feeding system ..................................................................................................................................................267

13.2 Fermenter technology .....................................................................................................................................268

13.3 Damage to turbo charger ...............................................................................................................................268

13.4 Corroded small end bushings .......................................................................................................................269

13.5 Failure of the generator ..................................................................................................................................269

13.6 Major damage ...................................................................................................................................................270

14 Prospects ........................................................................................................................................................271

15 Conclusions .....................................................................................................................................................271

16 Rules and regulations ....................................................................................................................................271

17 Literature ........................................................................................................................................................273

VIII Fuel Cell and Hydrogen Technology

1 Fuel cells .........................................................................................................................................................279

2 Properties of fuel cells ...................................................................................................................................279

3 Functioning of the fuel cells ..........................................................................................................................279

4 Fuel cells .........................................................................................................................................................280

4.1 Division of the fuel cells .................................................................................................................................280

4.1.1 Proton Exchange Membrane FC (PEMFC); also Polymer Electrolyte Fuel Cell (PEFC) ...280

4.1.2 High temperature PEMFC (HT-PEM) .........................................................................................282

4.1.3 Solid Acid Fuel Cell (SAFC) ............................................................................................................282

4.1.4 Anion Exchange Membrane FC (AEMFC) .................................................................................283

18 Contents

4.1.5 Direct-Methanol Fuel Cells(DMFC) ............................................................................................283

4.1.6 Ethanol FC (DEFC; DAFC) ..............................................................................................................284

4.1.7 Alkaline Fuel Cells (AFC)................................................................................................................284

4.1.8 Phosphoric Acid Fuel Cell (PAFC) ................................................................................................284

4.1.9 Molten Carbonate Fuel Cell (MCFC) ..........................................................................................285

4.1.10 Solid Oxide Fuel Cell (SOFC) .........................................................................................................286

4.2 Operating fuel cells ..........................................................................................................................................287

4.2.1 Power station usage ......................................................................................................................287

4.2.2 Building energy supply concepts ...............................................................................................288

4.2.3 Portable devices .............................................................................................................................289

4.2.4 Vehicle applications .......................................................................................................................289

4.2.5 Infrastructure ..................................................................................................................................291

4.2.6 Costs for vehicles having an electric drive ...............................................................................291

4.2.7 Burst protection .............................................................................................................................291

4.2.8 Research and Development (R & D) for fuel cell systems ...................................................292

5 Hydrogen .......................................................................................................................................................293

5.1 Properties of hydrogen ....................................................................................................................................293

5.2 Hydrogen generation .......................................................................................................................................293

5.2.1 Electrolysis .......................................................................................................................................294

5.2.2 Natural gas reformer .....................................................................................................................294

5.2.3 Chemical hydrogen extraction ...................................................................................................294

5.2.4 Steam reformation .......................................................................................................................295

5.2.5 Reformation from sources of energy containing carbon .....................................................295

5.2.6 Hydrogen from ethanol ................................................................................................................295

5.2.7 Solar hydrogen ...............................................................................................................................295

5.2.7.1 Hydrosol ...................................................................................................................295

5.2.7.2 SOLZINC solar hydrogen ..................................................................................296

5.3 Hydrogen purification .....................................................................................................................................296

5.3.1 Dust extraction ...............................................................................................................................296

5.3.2 Desulphurisation ............................................................................................................................296

5.3.3 CO2 scrubbing ..................................................................................................................................297

5.3.4 Precision purification method ....................................................................................................297

5.3.4.1 Catalytic method ...................................................................................................297

5.3.4.2 Pressure swing adsorptions ................................................................................297

5.3.4.3 Membrane method ..............................................................................................297

5.3.4.4 Metal hydrides .......................................................................................................297

5.3.4.5 Digester gas purfication (biogas purfication) ................................................297

5.4 Transport and storage .....................................................................................................................................298

5.4.1 Hydrogen as a storage medium for wind power ...................................................................298

5.4.2 Hydrogen storage ..........................................................................................................................298

5.4.2.1 Pressure gas storage .............................................................................................298

5.4.2.2 Liquid gas storage .................................................................................................299

5.4.2.3 Metal hydride storage ..........................................................................................299

Contents 19

5.4.2.4 Graphite storage ...................................................................................................300

5.4.3 Other storage developments ......................................................................................................300

6 Hydrogen safety .............................................................................................................................................300

6.1 Embrittlement of metals ................................................................................................................................301

7 Rules ................................................................................................................................................................301

8 Predictions for the fuel cell market ...............................................................................................................303

9 Research and development (summary) ........................................................................................................303

10 Source citation and Internet addresses .......................................................................................................305

IX Geothermics

1 Energy potential .............................................................................................................................................311

2 Manners of use ...............................................................................................................................................311

2.1 Principle of hydrothermal use .......................................................................................................................312

2.2 Geothermics close to the Earths surface ...................................................................................................313

2.2.1 Working principles of heat pumps ............................................................................................314

2.2.2 Ground water heat pumps ..........................................................................................................315

2.2.3 Ground heat collectors .................................................................................................................315

2.2.4 Ground source heat exchangers (GSHEs).................................................................................316

2.2.5 Concrete parts in contact with the soil - Energy piles .........................................................317

2.3 Hot Dry Rock (HDR) Process ...........................................................................................................................318

2.4 Geothermal power stations ...........................................................................................................................319

2.4.1 Direct use of the fluid in a turbine ............................................................................................319

2.4.2 Binary installations ........................................................................................................................320

2.4.2.1 Organic Rankine Cycle (ORC) ..............................................................................321

2.4.2.2 Kalina cycle .............................................................................................................322

2.4.2.3 Kalina power stations in Germany ...................................................................322

2.5 Local and district heating networks.............................................................................................................322

2.5.1 The Renewable Energies and Heat Act (EEWrmeG) ............................................................322

2.5.2 Geothermics contribution to cover heat demands ...............................................................323

3 Geothermic drilling processes .......................................................................................................................323

3.1 Hydraulic Boring ...............................................................................................................................................323

3.2 In-hole rotary-percussive drilling..................................................................................................................323

3.3 Hammer drilling (percussive) .......................................................................................................................324

3.4 Rotary drilling ....................................................................................................................................................324

3.5 Percussive drilling .............................................................................................................................................324

3.6 Auger drilling (rotary) .....................................................................................................................................324

20 Contents

3.7 Top-drive drilling (rotary) ................................................................................................................................324

3.8 Turbine drilling (rotary) ...................................................................................................................................324

4 The Discovery Risk ......................................................................................................................................325

5 Business interruption.....................................................................................................................................325

6 Summary ........................................................................................................................................................325

7 Internet adresses ...........................................................................................................................................326

X CO2 capture, transport and storage

1 Introduction ...................................................................................................................................................331

1.1 Coal as a source of energy ..............................................................................................................................331

2 The CCS process steps ...................................................................................................................................332

2.1 Overview ............................................................................................................................................................332

2.2 The CO2 capture .................................................................................................................................................333

2.3 Range of application of the technologies ..................................................................................................333

2.4 The post-combustion process ......................................................................................................................334

2.4.1 The CO2 capture process in the post-combustion process ..................................................335

2.4.2 The need for research and development .................................................................................336

2.4.3 Efficiency and investment costs .................................................................................................337

2.4.4 An example of a pilot plant RWE Niederaussem ................................................................337

2.5 The pre-combustion process .........................................................................................................................337

2.5.1 The gasifier ......................................................................................................................................339

2.5.2 The CO2 capture process in the post-combustion process ..................................................339

2.5.3 The need for research and development .................................................................................340

2.5.4 Efficiency and investment costs .................................................................................................340

2.5.5 Pilot plant installations ...............................................................................................................341

2.6 The oxyfuel process ..........................................................................................................................................341

2.6.1 The need for research and development .................................................................................342

2.6.2 A pilot plant installation example of an oxyfuel power plant

Schwarze Pumpe, Spremberg .....................................................................................................342

2.7 A comparison of the processes......................................................................................................................343

3 The CO2 transport ...........................................................................................................................................343

3.1 CO2 compression ...............................................................................................................................................344

3.2 CO2 liquefaction ...............................................................................................................................................344

3.3 Ship transport ...................................................................................................................................................344

3.4 Pipelines ..............................................................................................................................................................345

Contents 21

4 Geological CO2 storage ...................................................................................................................................345

4.1 Exploited salt mines .........................................................................................................................................346

4.2 Coal seams with a depth of more than 2,500 m ......................................................................................346

4.3 Exploited coal seams .......................................................................................................................................347

4.4 Exploited oil fields ............................................................................................................................................347

4.5 Exploited natural gas fields ............................................................................................................................347

4.6 Saline aquifers ...................................................................................................................................................348