Over 85,000 Powerwalls fed California’s grid in a record 745 MW dispatch

On October 6, more than 85,000 Powerwall owners across California sent over 600 megawatts from their garage batteries into the state grid during the evening peak. Combined with batteries enrolled through Sunrun, the dispatch reached 745 MW, the largest residential battery event California has recorded and 28% above the 580 MW mark set a month earlier.

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The event came during a prolonged heat wave, one day after a 669 MW dispatch that had itself topped the old record. Between them, the October 5 and October 6 calls turned thousands of private batteries into something grid operators treat as a power plant they can order up by price signal.

Tesla’s 600 MW and the Sunrun total

Tesla Energy said that more than 85,000 Powerwall owners dispatched over 600 MW on October 6, and called it, in the words relayed by Electrek’s report on the dispatch, “a new record for the largest Powerwall VPP event.” Tesla announced that figure on October 8.

The 745 MW number is a combined one. Sunrun, the residential solar and storage company, announced it on October 14 in its record-dispatch press release, which credits the joint fleet of Sunrun and Tesla batteries and does not split the total between the two. Electrek estimated that roughly 80% of the record came from Powerwalls, which is consistent with Tesla reporting more than 600 of the 745 MW. Sunrun said the dispatch was enough to power every household in San Francisco and San Jose at peak hours, and that it has more than 120,000 residential batteries enrolled in California grid programs.

Because the 745 MW is a joint figure, the 85,000 count describes only the Powerwall share. The Sunrun release gives no separate count of the batteries behind the remaining capacity, so the number of homes involved in the full record is higher than 85,000 but not stated in either company’s account.

DSGS and ELRP: the programs that trigger the batteries

Both October dispatches were called under the Demand Side Grid Support program, which the California Energy Commission runs. According to Sunrun, each call followed a California ISO day-ahead locational marginal price above $200 per megawatt-hour, and the dispatches were made at the request of the Energy Commission and utilities. The commission’s March 2026 workshop notice on the fifth edition of the DSGS guidelines shows the rules are still being rewritten, including a revised draft that limits battery eligibility to projects with a permission-to-operate date on or before December 31, 2025.

October 5 added a second program. Sunrun said it was the first event this year in which DSGS and the Emergency Load Reduction Program were called concurrently across all participating investor-owned utility territories. The California Public Utilities Commission describes the Emergency Load Reduction Program as a five-year pilot that pays customers to cut use or add supply during grid emergencies, with Pacific Gas and Electric, San Diego Gas and Electric and Southern California Edison handling enrollment and payments. Residential Power Saver Rewards participants earn $1 per kilowatt-hour, and there is no penalty for sitting an event out.

What makes the record unusual is who is on the other end of the call. A utility-scale peaker plant is a single asset with one operator, while this dispatch was thousands of separate household systems responding to the same price trigger within the same evening window. Electrek’s September coverage noted that typical natural gas peaker plants run about 50 to 250 MW each, so the October total exceeds what several of them would deliver together. Sunrun, for its part, says customers are compensated for taking part in these events.

From 580 MW to 745 MW in four weeks

The previous high came on September 9, when Sunrun and Tesla pulled 580 MW from more than 140,000 home batteries statewide, as Electrek reported in September. About 110,000 of those were Powerwalls delivering 517 MW, while more than 30,000 batteries from other manufacturers in Sunrun’s fleet added 63 MW. Before that, the residential record of 539 MW had stood since July 29, 2025.

Set against those numbers, the October event is notable for how the pieces changed. Tesla’s own count of participating owners, 85,000, is smaller than the roughly 110,000 Powerwalls behind September’s 517 MW, yet the Powerwall contribution rose above 600 MW. Neither company has published an explanation, such as longer discharge settings, larger systems or a different mix of enrolled customers, so the gap remains an open question rather than a documented trend.

The Google-funded plant planned around San Jose

Sunrun CEO Mary Powell framed the results as proof that customers are being compensated for helping strengthen grid reliability, and that California can lean on batteries already installed in homes instead of relying only on costly new power plants.

The next test is local. Sunrun said a Google-funded distributed power plant developed with PG&E, centered on the San Jose area, is expected to enroll nearly 21,000 existing flexible devices through Tesla and Everyday Electric, the company formerly known as Renew Home, with initial dispatching expected to begin in October 2026. The release notes the arrangement is covered by a non-binding letter of intent, and every figure in it is Sunrun’s own reporting rather than a number verified by the grid operator.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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