Pumped Storage

Left Column: 

Water Authority and City of San Diego explore pumped storage project

As construction on the San Vicente Projects wound down, the Water Authority and the City of San Diego ramped up their coordinated assessment of a potential pumped storage energy project at the reservoir. The Water Authority and the City are co-permittees on a preliminary permit issued by the Federal Energy Regulatory Commission in May that allows the agencies to pursue development of a pumped storage facility at San Vicente Reservoir. The preliminary permit is an early step in the process of determining if and how the Water Authority and the City could develop the project during the next decade.

The potential pumped storage project could supplement the region's energy needs with up to 500 megawatts of energy production during peak demand periods, enough to supply approximately 325,000 homes.

The San Vicente Pumped Storage Project would include construction of a small reservoir above San Vicente Reservoir, along with an underground powerhouse at San Vicente Reservoir and a tunnel and pipeline system to connect the two reservoirs. The powerhouse would contain reversible pump-turbines. During peak energy demand, water would flow downhill through the turbines to generate carbon-free power. During off-peak periods, water would be pumped to the upper reservoir.

Numerous steps involved in evaluating the project were completed during the year. In February, the Water Authority Board approved a partnership agreement with the City of San Diego and funding for technical and professional services to advance in the regulatory process. That was followed in May by Board approval for submitting the Preliminary Application Document/Notice of Intent to FERC, along with approval for starting the process of selecting an Owners’ Advisor Team to perform additional analyses of the project's viability and recommend a business model for implementation of the project. Staff completed the FERC PAD/NOI in June for submission to FERC.




Since its start-up in 2012, the Lake Hodges Pumped Storage Facility has produced $7.7 million in revenue, including $3.1 million in fiscal year 2015.

Pumped storage facility tops 97 percent ‘uptime’

Regular upkeep allowed the Lake Hodges Pumped Storage Facility to top 97 percent availability during the fiscal year, an important achievement for ensuring the facility continues to maximize revenues that offset the cost of providing a safe and reliable water supply.

As part of planned operations, the Lake Hodges facility was taken off-line in March and November for inspections and preventative maintenance. The shutdowns allowed the facility’s contract operator to cost-effectively perform annual maintenance while maximizing facility availability for pumped storage operations.