Power Plants Create Giant Water Battery

California is a leader in renewable energy, and the state has pledged to use only clean sources for electricity, including wind and solar power, by 2045. One hurdle is energy storage, but an old solution involving water may help the state reach its goal of zero emissions. The solution is “pumped storage,” which uses water in reservoirs at different elevations to smooth the fluctuations of intermittent power from the wind and sun, and makes electricity available when it is needed. California has mandated 60% renewable energy sources for its power generation by 2030, and all zero-emission sources by 2045, which could include nuclear generation along with renewables.