Summary
Sunrun says its and Tesla’s residential battery fleets delivered 745 MW of peak power to California’s grid on Oct. 6, 2026, after a 669 MW dispatch the previous evening. The company reported a combined output, not separate totals for each fleet.
Sunrun says residential batteries operated by the company and Tesla delivered a record 745 megawatts (MW) of peak power to California’s grid on Oct. 6, 2026. The dispatch followed a 669 MW delivery the previous evening, during a prolonged heat wave. Sunrun described both as the largest residential distributed power plant dispatches in US history.
The Oct. 6 output was enough to power all households in San Francisco and San Jose combined during peak hours, according to Sunrun. The company reported a combined figure for the two fleets, without a separate total for Sunrun and Tesla.
How the batteries supported the grid
At the request of the California Energy Commission and utilities, the companies discharged home batteries during multi-hour evening peak periods. A distributed power plant coordinates smaller energy resources—such as batteries in individual homes—so they can supply power when the wider grid needs it. The dispatches took place through California grid-support programmes.
On Oct. 5, California’s Demand Side Grid Support (DSGS) programme and Emergency Load Reduction Program (ELRP) called for concurrent dispatches across all participating investor-owned utility service territories for the first time that year, Sunrun said. On both evenings, DSGS dispatches were triggered after the California Independent System Operator’s day-ahead locational marginal electricity price exceeded $200 per megawatt-hour. A locational marginal price is the wholesale electricity price at a particular point on the grid.
Sunrun said the battery deliveries increased the grid’s operating margin and put downward pressure on real-time energy prices. The company also reported that more than 120,000 of its residential batteries are enrolled to support California’s grid.
A record built over successive dispatches
The Oct. 6 total exceeded a 580 MW residential dispatch recorded on Sept. 9, 2026, and a 539 MW record from July 2025. Those successive totals show the scale at which aggregated home storage can contribute power during periods of high demand. They offer utilities another resource to call on alongside large power plants when evening demand rises.
The 745 MW figure describes peak power—the rate at which electricity was supplied—not the total energy delivered over the event, which would be measured in megawatt-hours. The release gives the combined peak output of the Sunrun and Tesla fleets, rather than a company-by-company breakdown.