California's utility-scale battery fleet has grown from 232 MW in 2018 to nearly 15,000 MW today — a more than 60-fold increase, with growth accelerating sharply since 2021.
Utility-scale battery storage capacity sited in California, year-end (MW)
Source: U.S. Energy Information Administration, Form EIA-860/860M. 2026 figure is through May, not a full year.