PV Fleet Output Modeling, Prediction and Forecasting

Utility planners and operators are accountable for system reliability. As the amount of PV is increasing on the utility system, they are concerned about how short-term PV system output changes may affect utility system stability. This concern extends across the utility system, ranging from individual distribution feeders to state-wide balancing areas.

Several research activities have been undertaken by the California Solar Initiative (CSI) and others (e.g., Department of Energy) to address high penetration PV issues. Clean Power Research (CPR) was awarded one of the CSI RD&D contracts: “Advanced Modeling and Verification for High Penetration PV.”

Several key tasks are being complted under this contract:

• Create a state-of-the-art high resolution irradiance data base (1 km spatial, half-hour temporal resolution) for the entire state of California (https://ca.solaranywhere.com/)
• Develop and validate PV output variability algorithms to quantify PV output variability based on a minimal amount of data
• Integrate results into a distribution system engineering and analysis tool

CPR subsequent has been awarded a follow-on contract with the California Energy Commission (CEC) to demonstrate this approach for the state of California at the Independent System Operator (ISO) level.

Together, these efforts are leading to the development of a software service that will enable planners and operators to predict PV output variability without using ground-based measurements for applications ranging from single distribution systems to entire balancing areas.

Results of these efforts will be presented. Measured data collected for a fleet of high penetration locations will be included.