San Diego is looking for 500 MW of pumped hydro to integrate renewables
San Diego is looking beyond batteries for solutions to match supply and demand of electricity as solar penetrations increase.
Lithium-ion batteries have dominated not only conversations about the future of energy storage, but deployment in recent years. The batteries are relatively quick to install, can be scaled up or down from residential to grid-scale applications and can be sited pretty much anywhere.
Furthermore, falling costs are making such systems increasingly attractive for applications up to and including four-hour “load-shifting”, such as to accommodate California’s oversupply of mid-day power from solar and need for evening power.
The largest lithium-ion battery known to pv magazine is a 30 MW, 120 megawatt-hour (MWh) battery installed in Southern California in January, although Telsa is planning to build a 129 MWh battery in Australia. But yesterday, San Diego announced that it is looking to build an energy storage installation that could be more than 15 times as big.
The San Diego County Water Authority has issued a request for proposals (RFP) for an energy storage facility that would pump water between two reservoirs, and release this water into a hydroelectric plant when needed. The facility will be up to 500 MW in capacity, dwarfing existing battery storage systems.
This should be no surprise. While more capacity of lithium-ion batteries has been put online in recent years in the United States the global scale of pumped hydroelectric storage is far greater, with the U.S. Department of Energy reporting total capacity of at least 184 GW. This includes significant pumped hydro in Japan and European nations, as well as in the United States.
