The project would use San Diego’s existing San Vicente reservoir near Lakeside and a new, smaller reservoir located uphill.
- Proposals are due on Sept. 12. Evaluations will occur through the fall with negotiations for a final contract expected by year end.
The San Diego County Water Authority issued a request for interest for the proposed pumped storage project in January that drew 18 respondents.
The respondents included five full-service entities offering to finance, design, permit, build, and operate the project, as well as responses from two developers, five off-takers, and six parties interested in building the project, providing equipment for the project, or serving as a consultant for engineering, procurement, and construction services.
SDCWA said in a release that the responses confirmed that the project would be a valuable resource helping integrate more variable generation and providing other grid support services. The project would also help utilities meet the state mandate to procure 50% of their energy from renewable resources by 2030.
The pumped storage would use existing resources, including the San Vincente reservoir and a nearby high voltage transmission line. The plant would be able to prove five to eight hours of energy at a time.
SDCWA’s San Vicente Dam Raise Project, completed in 2014, provided additional energy storage potential by creating about 105,000 acre-feet of new regional carryover storage water supplies and 52,000 acre-feet of new emergency storage capacity.
SDCWA already operates a pumped hydro plant at Lake Hodges, which began operating in 2011, pumping water to the Olivenhain reservoir and generating up to 40 MW.
“This potential project is an exciting and innovative opportunity to optimize our water facilities to benefit our ratepayers while helping the region as a whole meet its energy needs,” Mark Muir, chair of the Water Authority’s board of directors, said in a statement.