Photovoltaic Project Proposal Cramer Hall Portland State University

Photovoltaic Project Proposal: Cramer Hall Portland State University Christopher Hinton July 27, 2003 Solar Energy Technology Summer, 2003 Dr. Carl Wamser

Proposal Outline I. Cover Letter II. Overview of turnkey PV systems A. System Size 1. DC k. Wp (kilowatts peak) 2. Actual STC rating 3. Estimated Output (AC k. Wp) B. Estimated Annual Energy Production (k. Wh) C. Estimated System Costs 1. Total Equipment Costs 2. Installation/Consulting 3. Design and Engineering 4. Permitting 5. Educational Kiosk D. Incentive Credits 1. Energy Trust Grant 2. Business Energy Tax Credit E. Triple Bottom Line 1. Cost and Payback Analysis 2. Environmental Benefit 3. Community Asset III. Supporting Worksheets IV. Product Specifications

Proposal Challenges l l l l Estimate energy production Prepare system designs Shop for system components Itemize component quantities Itemize component costs Total costs for each system Analyze and select key systems by cost Present selected systems

Estimating Energy Production l l l STC ratings vs. the real world DC kilowatts and AC kilowatts Two steps for an accurate estimate: 1. 2. DC to AC de-rating Solar Insolation and Climate (DC Watts)(de-rating factor) = AC Watts (output) AC Watts NREL’s PVWatts Calculator Local Estimated Annual Energy Production (k. Wh)

DC to AC de-rating Factors that affect PV system performance: 1. 2. 3. 4. 5. Module production tolerance (+/- 5%) Temperature (CEC recommends 89%) Dirt and dust (~93%) Mismatch and wiring losses (~95%) Inverter efficiency (~90%) Example: 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 California Energy Commission (CEC) A Guide to Photovoltaic (PV) System Design and Installation

DC to AC de-rating Worksheet

Solar Insolation and Climate

Energy Production Summary l DC to AC de-rating factor: 70% Based upon CEC guidelines and the Oregon Solar Electric Guide l Local Energy Production Potential: 1329. 58 k. Wh per AC k. W, annually PVWatts v. 2

Energy Production Worksheet

Module STC Worksheet

System Design Matching modules to inverters l Planning the layout l Selecting mounting hardware l

A Closer Look at Inverters Two types of inverters under consideration: l l Sunny. Boy 1800 (SMA-America) Sunny. Boy 2500 (SMA-America) Sunny. Boy 1800 l l l Output voltage: 120 Vac Recommended max PV power in: 2000 to 2200 Watts (STC) Max DC Voltage in: 400 Vdc Max AC power out: 1800 W Nominal AC power out: 1650 W Peak efficiency: 93. 5% Sunny. Boy 2500 l l l Output voltage: 240 Vac or 208 Vac (selected at time of purchase) Recommended max PV power in: 2800 to 3000 Watts (STC) Max DC Voltage in: 600 Vdc Max AC power out: 2500 W Nominal AC power out: 2200 W Peak efficiency: 94. 1%

Output Voltage l l l PSU currently uses both 120 V and 208 V AC 208 V is typically used on each leg of a 3 -phase power system Some debate/controversy over how to utilize inverters in a 3 -phase system: l l Is it possible to place a single inverter on just one leg of a 3 -phase system? Or is it necessary to use increments of three equally loaded inverters – one for each leg?

Inverter String Sizing

Inverter Limits Worksheet

Inverter String Sizing Worksheet

Planning the Layout: an Exercise in Trigonometry Unirac

Selecting Mounting Hardware Unirac

Calculating System Costs Mounting Hardware Price List l Mounting Hardware Quantities l Mounting Hardware Costs by System l Component Price List l Itemized Component Quantities by System l Itemized Component Costs by System l

The Solar. Mount Estimator (Thanks Unirac)

Solar. Mount Price List Worksheet

Solar. Mount Quantities Worksheet

Solar. Mount Costs Worksheet

Component Price List Worksheet

Component Quantities Worksheet

Component Costs Worksheet

Total Costs by System Worksheet

Overloaded with information yet? Me too…

So what does it all mean for PSU? Analyze systems by cost efficiency l Select representative systems for proposal l Add non-equipment-related costs l Present incentives l The “Triple Bottom Line” l

Graph: Cost per DC Watt

Forthcoming Changes and Additions l l l Add overview sheet for selected single-phase systems Add “Notes” sheet (similar to a reference page) Add to component worksheets: l l l PV combiner boxes AC disconnects (utility visible & lockable) Inverter communications & data logging equipment Change the way Green Tag sales are incorporated into “Payback” calculation to reflect finite contract terms (Green Tags can’t simply be sold until PV system has paid for itself). Tighten estimate for misc. equipment (wire, conduit, etc. ) Further research costs associated with educational kiosk

Project Timeline July 23 – Proposal submitted to PSU facilities director July 29 – Meeting with facilities director And Hopefully… Aug/Sept – Applications and permits filed Late Sept – System Installation

References California Energy Commission - A Guide to Photovoltaic (PV) System Design and Installation http: //www. sdenergy. org/pvweb/Installation_Guilde. pdf National Renewable Energy Lab – PVWatts Calculator http: //rredc. nrel. gov/solar/codes_algs/PVWATTS/ New Path Renewables – Solar vendor in Bend, OR http: //www. newearthworks. com Oregon Office of Energy – Oregon Solar Electric Guide http: //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 modules http: //www. sharpusa. com/solar/Solar. Landing/ SMA-America – Manufacturer of Sunny. Boy line of inverters http: //www. sma-america. com Unirac – Manufacturer of Solar. Mount hardware http: //www. unirac. com