California's batteries now cover a third of peak demand

21,112 MW of battery capacity

"Peak demand" is the single hour each year the state's electricity use is highest, almost always a summer heat wave — a scale nobody was building toward just seven years ago.

That's precisely the window the grid needs it most: batteries discharge as solar drops off in the early evening, right as demand is still climbing — the exact hours behind California's "duck curve."

Source: California Energy Commission, "California Surpasses 21,000 Megawatts of Battery Resources" (Aug. 2026)