Riverside County and Imperial County, California, USA

Wildcat Energy Storage Project for Riverside County and Imperial County, California

Status: Completed


According to the U.S. Energy Information Administration (EIA), in 2019, a total of 40.87 million metric tons of carbon dioxide (CO2) were emitted by the production processes of conventional power plants in California.  The state government has established a series of policies and regulations aimed at reducing these emissions. One of the most important is the Renewables Portfolio Standard (RPS) Program, which through Senate Bill 1078 in 2002 mandated an initial requirement that 20% of electricity retail sales be generated by renewable resources by 2017. In 2018, Senate Bill 100 was signed into law, increasing the RPS to 60% by 2030 and requiring that all the electricity in the state come from carbon-free resources by 2045.

Project Scope

The project consists of the design, construction and operation of the first phase of a 3.0-megawatt alternating current (MWAC) energy storage system to be constructed on vacant and undeveloped land. The first phase of the facility is expected to store and deliver up to 1,796 megawatt-hours (MWh) of energy a year, mainly for frequency control purposes. The project will provide resource adequacy benefits, which will be purchased by SCE pursuant to a to a 9.5-year energy storage resource adequacy agreement (ESRA).


The project will increase the energy storage capacity of the California grid, which will allow the system operator to reduce the use of ramp-up/ramp-down fossil-fuel power plants and manage the grid more efficiently. The project is expected to store and deliver up to 1,796 megawatt-hours (MWh) of energy a year, which would displace approximately 819 metric tons/year of CO2. The project will also help integrate electricity generated by intermittent renewable energy sources, such as solar and wind, and support a more reliable power grid, by minimizing power disruptions and reducing energy losses resulting from mismatches in supply and demand.