NREL, California Independent System Operator, and First Solar Demonstrate Essential Reliability Services with Utility-Scale Solar

NREL, the California Independent System Operator (CAISO), and First Solar conducted a demonstration project on a large utility-scale photovoltaic (PV) power plant in California to test its ability to provide essential ancillary services to the electric grid.

Photo of a large scale solar array

With increasing shares of solar- and wind-generated energy on the electric grid, traditional generation resources equipped with automatic governor control and automatic voltage regulation controls—specifically, fossil thermal—are being displaced. The deployment of utility-scale, grid-friendly PV power plants that incorporate advanced capabilities to support grid stability and reliability is essential for the large-scale integration of PV generation into the electric power grid, among other technical requirements.

Pioneering work done by NREL, First Solar, and AES in 2015 in West Texas and Puerto Rico provided a detailed understanding of the advanced capabilities offered by modern PV power plants.

The current CAISO-First Solar-NREL project is aimed at breaking new barriers to the provision of ancillary services by PV generation in terms of both plant capacity (300 MW) and system-level impacts. Taken as a whole, this work shows that PV power plants can be used to manage a variety of grid challenges on island systems, isolated interconnections, and within market environments in large synchronous systems.