California Residential Batteries Set New Record By Supplying 745 MW To Grid
Coordinated home battery dispatches from Sunrun and Tesla helped meet peak electricity demand during a prolonged California heat wave.
Residential batteries operated by Sunrun and Tesla delivered a record 745 megawatts of peak power to the California electricity grid on October 6. This dispatch, which occurred during a prolonged heat wave, surpassed the previous record of 669 MW set just one day earlier. These consecutive events represent the highest output for residential distributed power plants in the United States.
The energy releases were requested by the California Energy Commission and local utilities to support the grid during multi-hour evening peak periods. According to Sunrun, the 745 MW output provided enough electricity to power all households in San Francisco and San Jose combined. The coordinated effort helped increase the grid's operating margin and reduced real-time electricity prices.
The dispatches were facilitated through the Demand Side Grid Support program and the Emergency Load Reduction Program. These initiatives are triggered when the California Independent System Operator’s day-ahead locational marginal electricity price exceeds $200 per megawatt-hour. The October 5 event was notable for being the first time this year that both programs called for concurrent dispatches across all participating investor-owned utility service territories.
The recent peak of 745 MW marks a 28 percent increase over the previous record of 580 MW, which was established on September 9, 2026. Sunrun CEO Mary Powell stated that the events demonstrate how existing home energy infrastructure can provide power at a scale that strengthens grid reliability without the need for new power plants. Sunrun currently has over 120,000 residential batteries enrolled to support the California grid.
In a separate development, Sunrun, Tesla, and Everyday Electric have partnered with utility PG&E on a Google-funded project to enroll nearly 21,000 flexible energy devices. This initiative aims to test how distributed energy resources can address local grid constraints. Initial dispatches for this project are expected to begin in October.
