Sunrun and Tesla recently dispatched 580 MW of residential battery capacity to California through more than 140,000 home batteries
Tesla Powerwalls accounted for 517 MW of the 580 MW dispatched
A second dispatch the following day delivered more than 140 MW, says Sunrun
Sunrun and Tesla coordinated the release of 580 MW of residential battery capacity to the California grid on September 9, 2026 as high temperatures pushed up electricity demand. The companies claim this as the ‘largest residential distributed power plant dispatch event on record’.
Dispatched at the request of the California Energy Commission and utilities, the duo combined 517 MW from Tesla Powerwalls and 63 MW from additional batteries for this feat. This includes 110,000 Powerwalls of which 55% are owned and operated by Sunrun. The latter says it dispatched over 30,000 of its customers’ batteries from other manufacturers.
The battery dispatch was carried out through two California grid-support programs, with participating systems spread across the state. The events were triggered by high electricity prices—CAISO’s day-ahead locational marginal price exceeding $200/MWh—and heat-related demand.
In total, more than 140,000 home batteries supplied 580 MW of peak power to California’s grid during a three-hour dispatch. They followed up with a three-hour dispatch during peak hours at the request of Southern California Edison, delivering over 140 MW of battery capacity to the grid on September 10, 2026.
With these dispatches, Sunrun says they were able to discharge their customers’ home batteries to increase the grid’s operating margin and put downward pressure on real-time energy prices.
“This historic dispatch shows that the benefits of distributed energy go well beyond individual households as we help control the cost of electricity for all Californians and reduce the need for new costly poles and wires,” said Sunrun CEO Mary Powell.
A report commissioned by the two companies from The Brattle Group estimated that programs of this type could provide up to $206 million in net cost savings to Californians by 2028.
Sunrun and Tesla joined hands with Renew Home in June 2026 to provide over 16 GW of flexible grid capacity by combining home batteries, smart thermostats and V2G resources (see Sunrun, Tesla, Renew Home Launch 16 GW VPP).
