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Private partner sought to develop 500 MW San Vicente pumped storage project in California, USA

The San Diego County Water Authority has issued a request for proposals (RFP) seeking a private partner to develop and operate the 500 MW San Vicente pumped energy storage project in California.

The project, which is planned jointly by the water authority and the City of San Diego, aims to maximize the value of the existing San Vicente reservoir for on-demand energy generation to support the state’s clean energy goals.

Proposals are due by 3 November for a full-service, multidisciplinary team capable of delivering and operating the project. The scope of work is divided into two phases with preliminary work in a first phase and implementation work in a second phase. The RFP details the scope of work required for development of the project, including a financial plan.

In July 2021, the San Vicente Energy Storage Facility received US$ 18 million in the state budget, enough to advance it through initial design, environmental reviews and the federal licensing process. The water authority and the city are preparing to launch federal and state environmental reviews and seek a project license from the Federal Energy Regulatory Commission. Those components are expected to take at least four years, with construction completion forecast for 2030.

The San Vicente project would create a small upper reservoir above the existing San Vicente Reservoir in Lakeside, along with a tunnel system to connect the two reservoirs and an underground powerhouse that would contain four 125 MW reversible pump-turbines. The San Vicente project would be a major asset to help avoid rolling blackouts through on-demand energy production while helping to meet state climate goals, according to a press release issued on 14 September.

The San Vicente project would provide long-duration stored energy, which will assist in meeting peak power demand periods throughout southern California and help meet the goals of Senate Bill 100, which requires 60 per cent of renewable energy by 2030 and 100 per cent zero-carbon energy resources in the state by 2045. The pumped storage energy project could store 4000 MWh per day of energy, or provide 500 MW of capacity for eight hours, according to the state water authority. It would as a result help balance the grid and enhance system reliability by supplementing California’s power supply needs during peak demand as well as integrating wind and solar power generation.

In addition, it would mitigate costs for water ratepayers across the San Diego region by generating additional revenue to help offset the cost of water purchases, storage and treatment. The critical infrastructure project will create more than 1000 construction-related jobs in addition to its other benefits. The facility would be a closed loop, off-stream system and as a result the exchange of water between the two reservoirs would not consume water or interfere with water supply, water quality, fisheries, or recreational uses of the San Vicente Reservoir. This also means that its power production and grid services would not be affected by water shortages as it would not be reliant on runoff that can fluctuate significantly from year to year. Last but not least, the San Vicente reservoir is near major electricity transmission facilities, which would allow the project to play a central role in integrating solar and wind energy from across the Southwest for use in San Diego County.

Details are included in the RFP document, which can be viewed upon registration at For further information, contact: Melissa Cha, Management Analyst, San Diego County Water Authority, 4677 Overland Avenue, San Diego, CA 921231233; Tel.: +1 858 522 6804; Fax: +1 858 268 7802; E-mail: