Photovoltaic Project Proposal:Photovoltaic Project Proposal:Cramer HallCramer Hall

Portland State UniversityPortland State University

Solar Energy TechnologySolar Energy TechnologySummer, 2003Summer, 2003

Dr. Carl WamserDr. Carl Wamser

Christopher HintonJuly 27, 2003

Proposal OutlineProposal OutlineI. Cover LetterI. Cover LetterII. Overview of turnkey PV systemsII. Overview of turnkey PV systems

A. System SizeA. System Size1. DC kWp (kilowatts peak)1. DC kWp (kilowatts peak)2. Actual STC rating2. Actual STC rating3. Estimated Output (AC kWp)3. Estimated Output (AC kWp)

B. Estimated Annual Energy Production (kWh)B. Estimated Annual Energy Production (kWh)C. Estimated System CostsC. Estimated System Costs

1. Total Equipment Costs1. Total Equipment Costs2. Installation/Consulting2. Installation/Consulting3. Design and Engineering3. Design and Engineering4. Permitting4. Permitting5. Educational Kiosk5. Educational Kiosk

D. Incentive CreditsD. Incentive Credits1. Energy Trust Grant1. Energy Trust Grant2. Business Energy Tax 2. Business Energy Tax

CreditCreditE. Triple Bottom LineE. Triple Bottom Line

1. Cost and Payback Analysis1. Cost and Payback Analysis2. Environmental Benefit2. Environmental Benefit3. Community Asset3. Community Asset

III. Supporting WorksheetsIII. Supporting WorksheetsIV. Product SpecificationsIV. Product Specifications

Proposal ChallengesProposal Challenges

Estimate energy productionEstimate energy production Prepare system designsPrepare system designs Shop for system componentsShop for system components Itemize component quantitiesItemize component quantities Itemize component costsItemize component costs Total costs for each systemTotal costs for each system Analyze and select key systems by costAnalyze and select key systems by cost Present selected systemsPresent selected systems

Estimating Energy ProductionEstimating Energy Production

STC ratings vs. the real worldSTC ratings vs. the real world DC kilowatts and AC kilowattsDC kilowatts and AC kilowatts Two steps for an accurate estimate:Two steps for an accurate estimate:

1.1. DC to AC de-ratingDC to AC de-rating

2.2. Solar Insolation and ClimateSolar Insolation and Climate

(DC Watts)(de-rating factor) = AC Watts (output)(DC Watts)(de-rating factor) = AC Watts (output)

AC Watts AC Watts NREL’s PVWatts Calculator NREL’s PVWatts Calculator Local Estimated Annual Energy Production (kWh)Local Estimated Annual Energy Production (kWh)

DC to AC de-ratingDC to AC de-rating

Factors that affect PV system performance:Factors that affect PV system performance:1.1. Module production tolerance (+/- 5%)Module production tolerance (+/- 5%)2.2. Temperature (CEC recommends 89%)Temperature (CEC recommends 89%)3.3. Dirt and dust (~93%)Dirt and dust (~93%)4.4. Mismatch and wiring losses (~95%)Mismatch and wiring losses (~95%)5.5. Inverter efficiency (~90%)Inverter efficiency (~90%)

Example:Example:100 watts (STC rating) x 0.95 (tolerance) x 0.89 (temp) x 100 watts (STC rating) x 0.95 (tolerance) x 0.89 (temp) x 0.93 (dirt) x 0.95 (wiring) x 0.90 (inverter) = 67 watts 0.93 (dirt) x 0.95 (wiring) x 0.90 (inverter) = 67 watts

California Energy Commission (CEC) A Guide to Photovoltaic (PV) System Design and Installation

DC to AC de-rating WorksheetDC to AC de-rating Worksheet

Solar Insolation and ClimateSolar Insolation and Climate

Energy Production SummaryEnergy Production Summary

DC to AC de-rating factor: 70%DC to AC de-rating factor: 70%Based upon CEC guidelines and the Based upon CEC guidelines and the Oregon Solar Electric GuideOregon Solar Electric Guide

Local Energy Production Potential:Local Energy Production Potential:

1329.58 kWh per AC kW, annually1329.58 kWh per AC kW, annually

PVWatts v.2PVWatts v.2

Energy Production WorksheetEnergy Production Worksheet

Module STC WorksheetModule STC Worksheet

System DesignSystem Design

Matching modules to invertersMatching modules to invertersPlanning the layoutPlanning the layoutSelecting mounting hardwareSelecting mounting hardware

A Closer Look at InvertersA Closer Look at InvertersTwo types of inverters under consideration:Two types of inverters under consideration:

SunnyBoy 1800 (SMA-America)SunnyBoy 1800 (SMA-America) SunnyBoy 2500 (SMA-America)SunnyBoy 2500 (SMA-America)

SunnyBoy 1800SunnyBoy 1800 Output voltage: 120 VacOutput voltage: 120 Vac Recommended max PV power in: 2000 to 2200 Watts (STC)Recommended max PV power in: 2000 to 2200 Watts (STC) Max DC Voltage in: 400 VdcMax DC Voltage in: 400 Vdc Max AC power out: 1800 WMax AC power out: 1800 W Nominal AC power out: 1650 WNominal AC power out: 1650 W Peak efficiency: 93.5%Peak efficiency: 93.5%

SunnyBoy 2500SunnyBoy 2500 Output voltage: 240 Vac or 208 VacOutput voltage: 240 Vac or 208 Vac (selected at time of purchase) (selected at time of purchase) Recommended max PV power in: 2800 to 3000 Watts (STC)Recommended max PV power in: 2800 to 3000 Watts (STC) Max DC Voltage in: 600 VdcMax DC Voltage in: 600 Vdc Max AC power out: 2500 WMax AC power out: 2500 W Nominal AC power out: 2200 WNominal AC power out: 2200 W Peak efficiency: 94.1%Peak efficiency: 94.1%

Output VoltageOutput Voltage

PSU currently uses both 120V and 208V ACPSU currently uses both 120V and 208V AC 208V is typically used on each leg of a 3-phase 208V is typically used on each leg of a 3-phase

power systempower system Some debate/controversy over how to utilize Some debate/controversy over how to utilize

inverters in a 3-phase system:inverters in a 3-phase system: Is it possible to place a single inverter on just one leg Is it possible to place a single inverter on just one leg

of a 3-phase system?of a 3-phase system? Or is it necessary to use increments of three equally Or is it necessary to use increments of three equally

loaded inverters – one for each leg?loaded inverters – one for each leg?

Inverter String SizingInverter String Sizing

Inverter Limits WorksheetInverter Limits Worksheet

Inverter String Sizing WorksheetInverter String Sizing Worksheet

Planning the Layout: an Exercise in Planning the Layout: an Exercise in TrigonometryTrigonometry

Unirac

Selecting Mounting HardwareSelecting Mounting Hardware

Unirac

Calculating System CostsCalculating System Costs

Mounting Hardware Price ListMounting Hardware Price ListMounting Hardware QuantitiesMounting Hardware QuantitiesMounting Hardware Costs by SystemMounting Hardware Costs by SystemComponent Price ListComponent Price List Itemized Component Quantities by SystemItemized Component Quantities by System Itemized Component Costs by SystemItemized Component Costs by System

The SolarMount EstimatorThe SolarMount Estimator(Thanks Unirac)(Thanks Unirac)

SolarMount Price List WorksheetSolarMount Price List Worksheet

SolarMount Quantities WorksheetSolarMount Quantities Worksheet

SolarMount Costs WorksheetSolarMount Costs Worksheet

Component Price List WorksheetComponent Price List Worksheet

Component Quantities WorksheetComponent Quantities Worksheet

Component Costs WorksheetComponent Costs Worksheet

Total Costs by System WorksheetTotal Costs by System Worksheet

Overloaded with information yet?Overloaded with information yet?

Me too…Me too…

So what does it all mean for PSU?So what does it all mean for PSU?

Analyze systems by cost efficiencyAnalyze systems by cost efficiencySelect representative systems for proposalSelect representative systems for proposalAdd non-equipment-related costsAdd non-equipment-related costsPresent incentivesPresent incentivesThe “Triple Bottom Line”The “Triple Bottom Line”

Graph: Cost per DC WattGraph: Cost per DC Watt

Forthcoming Changes and Forthcoming Changes and AdditionsAdditions

Add overview sheet for selected single-phase systemsAdd overview sheet for selected single-phase systems Add “Notes” sheet (similar to a reference page)Add “Notes” sheet (similar to a reference page) Add to component worksheets:Add to component worksheets:

PV combiner boxesPV combiner boxes AC disconnects (utility visible & lockable)AC disconnects (utility visible & lockable) Inverter communications & data logging equipmentInverter communications & data logging equipment

Change the way Green Tag sales are incorporated into Change the way Green Tag sales are incorporated into “Payback” calculation to reflect finite contract terms “Payback” calculation to reflect finite contract terms (Green Tags can’t simply be sold until PV system has (Green Tags can’t simply be sold until PV system has paid for itself).paid for itself).

Tighten estimate for misc. equipment (wire, conduit, etc.)Tighten estimate for misc. equipment (wire, conduit, etc.) Further research costs associated with educational kioskFurther research costs associated with educational kiosk

Project TimelineProject Timeline

And Hopefully…

Aug/Sept – Applications and permits filed

Late Sept – System Installation

July 23 – Proposal submitted to PSU facilities director

July 29 – Meeting with facilities director

ReferencesReferencesCalifornia Energy Commission - A Guide to Photovoltaic (PV) System Design and

Installationhttp://www.sdenergy.org/pvweb/Installation_Guilde.pdf

National Renewable Energy Lab – PVWatts Calculatorhttp://rredc.nrel.gov/solar/codes_algs/PVWATTS/

New Path Renewables – Solar vendor in Bend, ORhttp://www.newearthworks.com

Oregon Office of Energy – Oregon Solar Electric Guidehttp://www.energy.state.or.us/renew/solar/PVGuide.pdf

Portland General Electric – Net metering service schedule

http://www.portlandgeneral.com/about_pge/regulatory_affairs/pdfs/schedules/sched_203.pdf

Sharp USA – Manufacturer of PV moduleshttp://www.sharpusa.com/solar/SolarLanding/

SMA-America – Manufacturer of SunnyBoy line of invertershttp://www.sma-america.com

Unirac – Manufacturer of SolarMount hardwarehttp://www.unirac.com