This project developed several different tools and products that will help utilities address issues related to integrating high penetration photovoltaics (PV) into the electric grid. Specifically, the project addresses the following issues identified in the Planning & Modeling for High-Penetration PV target area: Improved Online Solar Radiation Datasets, PV Model Validation, High Penetration PV T&D Model Integration, and Optimal Location Selection.

• Enhanced the spatial and temporal resolution of SolarAnywhere, the online satellite-based irradiance dataset. This enables the use of these high temporal and spatial resolution data in the various forecasting and planning tools needed to address high penetration of solar.

• Extended the capabilities of PVSimulator to include output variability and validate PV performance forecasts using two existing circuits with PV high-penetration in California. This will enable better forecasting in planning tools used by utilities.

• Integrated PV modeling capabilities with the Distribution Engineering Workstation distribution engineering and analysis tool. This allows system planners to model the effects of cloud transients, bi-directional load flows, and the attributes of today's advanced inverter technologies.

• Created a PV value assessment tool that takes technical inputs from the distribution planning process and calculates the economic value of a specific PV fleet configuration. This enables the distribution planner to optimize the trade-offs and identify the optimal locations of PV systems.

The tools and data streams developed as part of this work are available for public use by California installers, manufacturers, agencies, utilities, and others.

Final Project Report: Advanced Modeling and Verification for High Penetration PV. Hoff, T.E. Clean Power Research. April 2012. PDF (2.5 MB)

Preliminary Results

• Provided detailed data to CAISO for inclusion in 33% renewables case study. Summary of Preliminary Results of 33% Renewable Integration Study – 2010 CPUC LTPP Docket No. R.10‐05‐006. Report available at http://www.cpuc.ca.gov/NR/rdonlyres/E2FBD08E-727B-4E84-BD98-7561A5D45743/0/LTPP_33pct_initial_results_042911_final.pdf. Page 87.

Pending Patents

• Computer-Implemented System and Method for Estimating Power Data for a Photovoltaic Power Generation Fleet.

• Computer-Implemented System and Method for Determining Point-to-Point Correlation of Sky Clearness for Photovoltaic Power Generation Fleet Output Estimation.

• Computer-Implemented System and Method for Efficiently Performing Area-to-Point Conversion of Satellite Imagery for Photovoltaic Power Generation Fleet Output Estimation.

• Project Kick off Presentation Jul 2010 ( PDF ) (1.14 MB)

• VoteSolar Webinar on PV Power Output Variability

• Short-term Irradiance Variability: Station Pair Correlation as a Function of Distance.” ASES National Conference. Raleigh, NC. 2011. Draft available at http://www.asrc.cestm.albany.edu/perez/2011/short.pdf.

• PV output variability, the sheep in wolf’s clothing.” VoteSolar, March 2011. Recording available athttp://votesolar.org/tag/solar-output/

• Solar Forecasting: Modeling, Verification and High Penetration PV. SEPA. August 2011.Recording available at http://www.solarelectricpower.org/resources/multimedia-library.aspx?kw=sepa%20seminar.

• “PV Power Output Variability: Calculation of Correlation Coefficients Using Satellite Insolation Data.” ASES National Conference. Raleigh, NC. 2011. Draft available at  http://www.cleanpower.com/Content/Documents/research/capacityvaluation/SOLAR2011_36.pdf.

• “High Solar Penetration: Challenges on Day-Ahead and Multi-Day Forecasts.” AMS Summer Community Meeting. August 2011.

• “The Convergence of Distributed PV, Smart Grid & Storage.” SEPA Utility Solar Conference. August 2011. Available at  http://sepa.confex.com/sepa/2011usc/webprogram/Session1092.html.

• Final Project webinar presentation April 2012 PDF

• Webinar presenting final project results ( wmv file ) (82 MB)

• "Quantifying PV Power Output Variability." Solar Energy. October 2010. Volume 84, Issue 10, Pages 1782-1793. http://www.sciencedirect.com/science/article/pii/S0038092X10002380

• “Modeling PV Fleet Output Variability.” Solar Energy. Forthcoming. Draft available at http://www.cleanpower.com/Content/Documents/research/capacityvaluation/Modeling%20PV%20Fleet%20Output%20Variability.pdf

• “Parameterization of Site-specific Short-term Irradiance Variability.” Solar Energy. July 2011. Volume 85, Issue 7, Pages 1343-1353.  http://www.sciencedirect.com/science/article/pii/S0038092X11000995

• “Short-term Solar Irradiance Variability – Spatial and Temporal Characteristics.” Solar Energy. Submitted. Draft available at http://www.cleanpower.com/Content/Documents/research/capacityvaluation/Short-term%20irradiance%20variability%20-%20Station%20pair%20correlation%20as%20a%20function%20of%20distance.pdf

• “Solar Resource Variability: Myth and Fact.” Solar Today. August/September 2011. http://www.solartoday-digital.org/solartoday/20110910#pg48

• “Solar Power Generation in the US: Too Expensive or a Bargain?” Accepted to Energy Policy. Forthcoming. Draft available at http://www.cleanpower.com/Content/Documents/research/capacityvaluation/Solar%20Power%20Generation%20in%20the%20US%20-%20Too%20Expensive%20or%20a%20Bargain.pdf

• PV Power Output Variability: Correlation Coefficients.  Hoff, T.E., and R. Perez.  November 11, 2010.  Clean Power Research (www.cleanpower.com).  Draft (1.3 MB).

• “Parameterization of Site-specific Short-term Irradiance Variability.” Perez, T., S. Kivalov, J. Schlemmer, C. Hemker Jr., and T.E. Hoff. Paper.

• Partial validation of SolarAnywhere 2009 by UCSD. Available at http://www1.eere.energy.gov/solar/pdfs/highpen2wkshp_05intro_jkleissl_forecasting_110613.pdf, page 10.

• SolarAnywhere - Data for 2003-2011 in select areas of California will be made freely available through this grant funding as it becomes available.

• California high resolution solar data http://ca.solaranywhere.com (1 km grid 30 min interval)