TEP Solar Test Yard Data vs. Models
Photo by
Jacob Chinn
Upcoming Events / Conferences on Solar Power
 European PV Solar Energy Conference & 5th World PV conference & 36th 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.13 1-3pm on Church St – Giffords/TEP – by invitation
 Solar Power International (SPI) and SEPA/ SEIA meetings. 27,000 attendees, B2B theme
October 12-14 Los Angeles
 Scialog Conference Oct.12-15 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
 3rd Thin Film Summit USA Nov .30-Dec.1 San Francisco
 Solar Power Generation: utility scale Jan.25-26 2011 Las Vegas
 40th ASES May.16-21 2011 Raleigh, NC (2010 was in Phoenix)
 37th 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. 14 - Polymorphism in Titanyl Phthalocyanine -Implications for 3rd Gen. PV
Diogenes Placencia, UA Chemistry/Biochemistry Research Graduate Associate
 Sept. 21 - SOLON's Global Test Site Network Bill Richardson, Head of R & D, SOLON Corp.
 Sept. 28 - 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. 12 - Nanoarchitectured Polymers and Polymer Nanocomposites for Photovoltaic
Applications Dr. Bob Norwood, UA Optical Sciences Professor
 Oct. 19 - 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: www.uapv.org
TEP Solar Test Yard Data vs. Models
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
Collaborators:
Students:
Bill Henry, Chris Lindsey, and Co. - TEP
Vincent Lonij , Daniel Cormode, Nick Davidson,
Ryan Price , Deanna Lewis, Steve Pulver Niket
Thakkar, Alex Hickey, Adria Brooks, Tucker
Bundgard, Ingrid Noche
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
Support From:
Tucson Electric Power, AZRISE, Biosphere 2, SOLON Corporation, NREL, UA Graduate College,
Science Foundation Arizona, NASA Space Grant Consortium, Prism Solar Technologies
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
Collaborators:
Students:
Bill Henry, Chris Lindsey, and Co. - TEP
Vincent Lonij , Daniel Cormode, Nick Davidson,
Ryan Price , Deanna Lewis, Steve Pulver Niket
Thakkar, Alex Hickey, Adria Brooks, Tucker
Bundgard, Ingrid Noche
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
Support From:
Tucson Electric Power, AZRISE, Biosphere 2, SOLON Corporation, NREL, UA Graduate College,
Science Foundation Arizona, NASA Space Grant Consortium, Prism Solar Technologies
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:
www.UAPV.org
See:
interactive graphs, database tables, download pg.
Yields
Yf 
Relative Yields

  
ˆ
  STC  p1   1  p 2 T a ( t )  20  C   1  t years  p 3
S ( t )  A exp 
 uˆ p  Sˆ ( t ) 




A simple model for production based
on a solar position algorithm,
Ambient temperature de-rating,
and overall system degradation.


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 www.UAPV.org
• 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 www.UAPV.org
• 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)
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
PVsyst Outputs
Unisolar US64 (3J a-Si)
Shell ST40 (CIS)
PVsyst Outputs
Unisolar US64 (3J a-Si)
Shell ST40 (CIS)
PR = 0.77
PR = 0.69
kWh generated
PR = “performance ratio” =
kWp
kWh indicent
1000 W/m
2
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 www.UAPV.org
• 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 www.UAPV.org
• 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 2009.
• Presented degradation and partial-shade studies at PVSC 2010.
• 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.