Amid a surge of deals for battery-backed solar power plants and stand-alone storage stations relying on lithium-ion batteries, local government-run community choice aggregators in California are showing more interest in alternative technologies to save energy for longer periods of time.
According to a request for information issued June 3, nearly a dozen community choice aggregators, or CCAs, are seeking input from long-duration storage equipment suppliers and project developers to assist with their resource planning and help shape future competitive solicitations.
While California's CCAs and investor-owned utilities are signing long-term energy storage agreements that typically rely on 4 hours of lithium-ion battery storage to offset or augment their reliance on natural gas-fired peak power generation, the CCAs asked for details on resources that can offer at least 8 hours of discharge in the California ISO wholesale market while qualifying for the state's resource adequacy program.
As one possibility, the request points to pumped hydroelectric storage, a technology with by far the largest installed capacity of any energy storage approach but which has encountered considerable development obstacles. The CCAs also named alternative storage approaches such as flow batteries, hydrogen, compressed air and cryogenic energy storage.
The CCAs are seeking information on commercial status, project pricing, contract terms, charging sources, discharging capacity, efficiency and degradation, among other items.
The retail power agencies making the request are Clean Power Alliance, CleanPowerSF, East Bay Community Energy, MCE Clean Energy, Monterey Bay Community Power, Peninsula Clean Energy, Redwood Coast Energy Authority, San Jose Clean Energy, Silicon Valley Clean Energy, Sonoma Clean Power and Valley Clean Energy Alliance.
In recent years California's CCAs have taken over a large share of investor-owned utilities' energy procurement responsibilities, totaling roughly 25% of their retail electric demand. That could grow to 38% by 2022, according to the California Community Choice Association.