Photo by Jacob Chinn TEP Solar Test Yard Data vs. Models

Upcoming Events / Conferences on Solar Power  European PV Solar Energy Conference & 5 th World PV conference & 36 th IEEE PVSC Right now: Sept 6-11, Valencia Spain  Sept. 17 (alt Fridays) at 4pm. Energy Sciences Group meetings – Chemistry  Solar Energy Round Table Sept pm on Church St – Giffords/TEP – by invitation  Solar Power International (SPI) and SEPA/ SEIA meetings. 27,000 attendees, B2B theme October Los Angeles  Scialog Conference Oct at Biosphere2. Eric Mazur, Harvard Physics, Oct. 14 3:30 Optical Science Colloquium Arun Majumdar, Director of ARPA-E, Oct. 15 4:00 Special Seminar in Koffler 218 and: Oct. 15 7:00 pm public lecture  3 rd Thin Film Summit USANov.30-Dec.1 San Francisco  Solar Power Generation: utility scale Jan Las Vegas  40 th ASES May Raleigh, NC (2010 was in Phoenix)  37 th IEEE PVSC June 19-24, 2011 Seattle, WA (abstracts due Feb. 28, 2011)  SPIE Optics&Photonics: Solar Energy & Technology Aug.21-25, 2011 San Diego Lots more under: “IEEE smart grid”, “EPRI”, and “solarbuzz.com”

UA Solar Seminar Series  Sept. 7 - TEP Solar Test Yard Data vs. Models. - Alex Cronin, UA Physics Associate Professor  Sept Polymorphism in Titanyl Phthalocyanine -Implications for 3 rd Gen. PV Diogenes Placencia, UA Chemistry/Biochemistry Research Graduate Associate  Sept SOLON's Global Test Site Network Bill Richardson, Head of R & D, SOLON Corp.  Sept Planar Holographic Concentrators for PV Dr. Jose Castro, ECE Research Asst. Prof. &Solar Distallation Dr. Leslie Frame, UA Materials Science & Engineering Research Associate  Oct. 5 - Solar Concentrators, Illumination Uniformity and Conversion Efficiency Alan Kost, UA CIAN Engineering Research Center Administrative Director  Oct Nanoarchitectured Polymers and Polymer Nanocomposites for Photovoltaic Applications Dr. Bob Norwood, UA Optical Sciences Professor  Oct Water and Land Requirements for Solar Energy in the Southwest George Frisvold, UA Agricultural-Resource Economics Specialist  Nov.2 Dr. Susan Lysecky, UA ECE Asst. Prof., Dr. Janet Wang, UA ECE Asst. Prof.  Nov.9 Scott Wiedeman, Chief Scientist, Global Solar Energy Inc. Dr. Leslie Frame, UA MSE Research Associate  Nov 16 Dr. B.G. Potter, UA MSE Professor.

We’ve had over 2,000 visitors and given public lectures to over 6,000 people at the TEP Solar Test Yard --- Contact: Deanna Lewis:

Photo by Jacob Chinn TEP Solar Test Yard Data vs. Models

Project Objectives: Evaluate new PV system technologies Monitor performance of grid-tied PV systems Report Energy Yields and Degradation Rates of PV systems Assess Models that Forecast PV generation. Alex Cronin, UA Physics / Optical Sciences Students: Vincent Lonij, Daniel Cormode, Nick Davidson, Ryan Price, Deanna Lewis, Steve Pulver Niket Thakkar, Alex Hickey, Adria Brooks, Tucker Bundgard, Ingrid Noche Support From: Tucson Electric Power, AZRISE, Biosphere 2, SOLON Corporation, NREL, UA Graduate College, Science Foundation Arizona, NASA Space Grant Consortium, Prism Solar Technologies Collaborators: Bill Henry, Chris Lindsey, and Co. - TEP Ray Kostuk, Bill Conant, Joe Simmons, Warren Beck, Nate Allen, Pierre Meystre – UA Sarah Kurtz, Dirk Jordan, Ryan Smith - NREL Mark Shields, Ben Bourne – SunPower

TEP Solar Test Yard Data vs. Models Project Objectives: Evaluate new PV system technologies Monitor performance of grid-tied PV systems Report Energy Yields and Degradation Rates of PV systems Assess Models that Forecast PV generation. Alex Cronin, UA Physics / Optical Sciences Students: Vincent Lonij, Daniel Cormode, Nick Davidson, Ryan Price, Deanna Lewis, Steve Pulver Niket Thakkar, Alex Hickey, Adria Brooks, Tucker Bundgard, Ingrid Noche Support From: Tucson Electric Power, AZRISE, Biosphere 2, SOLON Corporation, NREL, UA Graduate College, Science Foundation Arizona, NASA Space Grant Consortium, Prism Solar Technologies Collaborators: Bill Henry, Chris Lindsey, and Co. - TEP Ray Kostuk, Bill Conant, Joe Simmons, Warren Beck, Nate Allen, Pierre Meystre – UA Sarah Kurtz, Dirk Jordan, Ryan Smith - NREL Mark Shields, Ben Bourne – SunPower

TEP PV test yard 4350 E. Irvington Rd.

TEP Solar Test Yard Data vs. Models Project Objectives: Evaluate new PV system technologies & Compare to Traditional flat plate PV Monitor performance of grid-tied PV systems Report Energy Yields and Degradation Rates of PV systems Assess Models that Forecast PV generation.

TEP Solar Test Yard Data vs. Models Project Objectives: Evaluate new PV system technologies & Compare to Traditional flat plate PV Monitor performance of grid-tied PV systems Report Energy Yields and Degradation Rates of PV systems Assess Models that Forecast PV generation.

AC Output every minute shown for 2 days: Data on-line at: See: interactive graphs, database tables, download pg.

A simple model for production based on a solar position algorithm, Ambient temperature de-rating, and overall system degradation. YieldsRelative Yields

Measured Degradation Rates

Measured Yields (kWh/kWp)

Comparison of final yields in 6 places

Measured Efficiency for 9 systems in Feb.

TEP Solar Test Yard Data vs. Models Project Objectives: Evaluate new PV system technologies & Compare to Traditional flat plate PV Monitor performance of grid-tied PV systems  see Report Energy Yields and Degradation Rates of PV systems  Big Spreads! Assess Models that Forecast PV generation.

TEP Solar Test Yard Data vs. Models Project Objectives: Evaluate new PV system technologies & Compare to Traditional flat plate PV Monitor performance of grid-tied PV systems  see Report Energy Yields and Degradation Rates of PV systems  Big Spreads! Assess Models that Forecast PV generation.

A more detailed model: efficiency has an irradiance coefficient, and a temperature coefficient

Efficiency every minute of the day x 1 year of sunny days

120 system-years (daily kwh/kwp)

Show distributions In Igor Pro

PV output simulation programs: PVSS (1977)  SOLCEL (1977) PV SOLSTOR (1979) PV, wind & storage PVForm (1985) systems approach to PV, LCOE predictor, battery models too. PVSIM (1996) better electrical description of PV PVMOD (1998) empirical charactarization of modules  PVDesignPro (MSES Corp. software 2004)  Sandia (SNL) model  Solar Advisory Model (SAM) by NREL and SNL Hysim (1996) military PV + diesel + battery Hybsim (2003) PV + diesel + battery + wind 4-parameter one diode model (1989)  TRNSYS (1990) … 5-parameter Array Performance Model (Wisconsin, CEC) (DeSoto 2004, 2006)  PV F-chart (Wisconsin 1985, 2001) PVWatts (v1, v2, IMBY tool, CSI EPBB Calculator) PVSYST (Geneva, since 1995, current version 5.2) RETScreen PV Project Model – economics and environmental impacts PVSol (since 1998, v4 in 2009) Polysun (Vela Solaris, Switzerland, 2009) economics include: financing, O&M costs, incentives, energy prices, fuel cost savings and system value INSEL SolarPro (Japan 1997) For a Review see Sandia 8258

Models for Irradiance (on POA): Liu 1963 (isotropic sky) Hay 1979 Davies and Hay 1980 (anisotropic sky) Perez 1987, 1988, Models often use data from: Meteonorm, satellite, TMY2/3, ISM-EMPA, Helioclim-1 NASA-SSE, WDRC, PVGIS-ESRA

Shell ST40 (CIS)Unisolar US64 (3J a-Si) PVsyst Outputs

PR = 0.77 Unisolar US64 (3J a-Si)Shell ST40 (CIS) PR = 0.69 PR = “performance ratio” = PVsyst Outputs

Look at PVWatts online. Look at PVsyst on this PC.

Slide reproduced from Chris Cameron 2009 workshop on PV modeling

(in)stability of the solar resource Daily totals of solar radiation were averaged with a 365-day wide boxcar filter to remove seasonal variations. The resulting 48-year history shows a 3% rms fluctuation and a range (max-min) that is 15% of the average. From the low irradiance in 1992 (after the Mt. Pinatubo eruption) until 1996, the annual irradiance increased 13% over 4 years. This 3 %/yr change in reference yield is one of the challenges for studying absolute degradation rates for PV systems.

Insolation correlations across AZ

More fluctuations at higher latitude

TEP Solar Test Yard Data vs. Models Project Objectives: Evaluate new PV system technologies & Compare to Traditional flat plate PV Monitor performance of grid-tied PV systems  see Report Energy Yields and Degradation Rates of PV systems  Big Spreads! Assess Models that Forecast PV generation.  PVsyst, Pvwatts, Sandia, CEC 5-p

TEP Solar Test Yard Data vs. Models Project Objectives: Evaluate new PV system technologies & Compare to Traditional flat plate PV Monitor performance of grid-tied PV systems  see Report Energy Yields and Degradation Rates of PV systems  Big Spreads! Assess Models that Forecast PV generation.  PVsyst, Pvwatts, Sandia, CEC 5-p. Concluions / Outlook: Installed 5 new TEP systems and 5 new SOLON systems since Presented degradation and partial-shade studies at PVSC Working with test yards at NREL, Sandia, Stuttgart, Cyprus, SOLON (x3). PV watts is usually within 10%. PVsyst is better but $800 & “Experts only” Sandia claims to be within 1%, given weather data. Goal: report new technology model coefficients for affiliates Outreach / Education Agenda – see final slide

Tours: we’ve had over 2,000 visitors since 2009, and given public lectures to over 6,000 people To learn more about outreach at TEP solar test yard: Energy Sciences Group Meeting: Sept 17 4pm.

Thanks.