Home batteries managed by Sunrun and Tesla delivered a record 745 megawatts (MW) of power to California’s electricity grid on the evening of 6 October 2026, during a heat wave, according to Sunrun.
In a release on 14 October, Sunrun said “consecutive records were set for the largest residential distributed power plant dispatches in U.S. history, delivering 669 megawatts on October 5 and a record-breaking 745 megawatts on October 6”. A distributed power plant links thousands of home batteries so they can feed power to the grid together, like one large power station.
How it worked
“At the request of the California Energy Commission and utilities, Sunrun and Tesla discharged home batteries to the grid during multi-hour evening peak periods,” Sunrun said. The batteries helped the grid when demand was high, adding to its safety margin and holding down real-time electricity prices.
Sunrun said the 745MW was “enough to power all households in San Francisco and San Jose combined during peak hours”. It said the dispatches were triggered after the grid operator’s day-ahead electricity price went above $200 per megawatt-hour.
Sunrun did not say how much of the power came from its own customers and how much from Tesla’s, and it did not give the total energy delivered in megawatt-hours or how long the dispatches lasted. MW measures the rate of power at a moment; megawatt-hours measure the total energy over time.
A run of records
According to Sunrun, the previous record was 580MW on 9 September 2026, which had beaten 539MW set in July 2025. Sunrun says it alone has more than 120,000 home batteries enrolled to support California’s grid.
“These record-setting events prove that the energy infrastructure already installed in people’s homes can deliver power at a scale that makes a real difference for the grid,” said Sunrun chief executive Mary Powell. She added that “customers are being compensated for helping strengthen grid reliability.”
Sunrun also said a Google-funded distributed power plant with the utility PG&E, involving Sunrun, Tesla and Everyday Electric and nearly 21,000 existing home devices in the San Jose area, is expected to begin initial dispatches this month.
What this means
- Home batteries are now a grid resource. Together they matched the output of a large power plant at peak times.
- It is a peak-time tool. The batteries helped in the evening, when demand is highest.
- The detail is limited. Sunrun gave no split between companies and no total energy figure.
Sources
- Sunrun, “Sunrun Leads Record Grid Dispatch Delivering Enough Energy to Power Every Home in San Francisco and San Jose”, 14 October 2026. https://investors.sunrun.com/news-events/press-releases/detail/384/sunrun-leads-record-grid-dispatch-delivering-enough-energy
Related stories
- Power for AI: A Draft Nuclear Review in Texas, and Batteries Versus Gas Peakers
- Who Pays for AI’s Power? Duke’s Data-Centre Deal, Google in Indiana and the Rush to On-Site Gas
- US Energy Department Orders Emergency Measures for the Mid-Atlantic Grid, Letting PJM Call on Data-Centre Backup Generators
- Tesla’s 4.3 Billion Battery Bet: Why Elon Musk Is Buying American
