California's 745 MW Home-Battery Record Is Sunrun's Headline, but Tesla Says Over 600 MW of It Came From 85,000 Powerwalls

Sunrun said on Oct. 14 that California home batteries delivered 745 MW to the grid on Oct. 6, a record, after 669 MW the evening before. Tesla's own figure for the same evening, as reported by Electrek, is more than 600 MW from more than 85,000 Powerwall owners.

The two numbers do not sit comfortably in one press release. Sunrun's release is titled "Sunrun Leads Record Grid Dispatch", and says Sunrun and Tesla discharged batteries together. Electrek's analysis notes that Sunrun's release does not split the total between its customers and Tesla's.

Four records in 14 months

The previous residential record was 539 MW on July 29, 2025. A dispatch on Sept. 9, 2026 reached 580 MW. Sunrun reports 669 MW on Oct. 5 and 745 MW on Oct. 6, and says that is enough to power every household in San Francisco and San Jose during peak hours.

1. July 29, 2025539 MW
2. Sept. 9, 2026580 MW
3. Oct. 5, 2026669 MW
4. Oct. 6, 2026745 MW

Source: Sunrun press release, Oct. 14, 2026, accessed 2026-10-17

Both October events were called after the CAISO day-ahead locational marginal price exceeded $200 a megawatt-hour, the trigger for the California Energy Commission's Demand Side Grid Support program. Oct. 5 was also the first time in 2026 that the commission's program and the CPUC's Emergency Load Reduction Program ran concurrent dispatches across all participating investor-owned utility territories, according to Sunrun.

Sunrun says more than 120,000 residential batteries are enrolled in California grid programs. Mary Powell, Sunrun's chief executive, said that "Instead of relying solely on costly new power plants to meet peak demand" California is using existing home batteries.

Tesla's share is the denominator that matters

Electrek's arithmetic puts Powerwalls at roughly 80 percent of the record: more than 600 MW out of 745. If that holds, the fleet Sunrun owns or operates delivered no more than about 145 MW of it, even though the release leads with Sunrun's name. That is our reading of the two documents, not a figure either company states, and it depends on Tesla's total sitting inside the 745.

Tesla's number also comes with a headcount, which Sunrun's does not. Dividing more than 600 MW by more than 85,000 owners gives about 7.1 kW per owner on Oct. 6. Electrek reports the September event as 517 MW from about 110,000 Powerwalls, or about 4.7 kW each.

Event	Powerwall MW	Owners	kW per owner
Sept. 9, 2026	517	about 110,000	4.7
Oct. 6, 2026	over 600	over 85,000	about 7.1

Electrek notes that 7 kW per home is above a Powerwall 2's 5 kW continuous output, and suggests the fleet now includes Powerwall 3 units rated at 11.5 kW and homes with more than one battery. The per-owner figure rose by half while the owner count fell by nearly a quarter, which neither company explains.

Megawatts without megawatt-hours

A megawatt is a rate. Grid value depends on how long the rate holds. Electrek points out that Tesla and Sunrun report only MW, with no MWh and no duration, so the energy delivered on Oct. 6 cannot be computed from either source. For scale only: 745 MW held for two hours would be 1.49 GWh, a figure we chose as an illustration and neither company reported. We covered a 1.4 GWh battery project built for Tesla separately.

Electrek describes multi-hour evening peaks. A smaller fleet gives a contrast: Vermont's 110-megawatt virtual power plant delivered 90 MW in July, per our earlier report, a ratio of 0.82 to its enrolled capacity that Sunrun and Tesla do not publish for California.

The Google and PG&E project starts this month

Sunrun's release adds a planned Google-funded distributed power plant with PG&E in the San Jose area. It would enroll nearly 21,000 existing devices from Tesla and Everyday Electric, formerly Renew Home, with initial dispatches expected in October 2026. The Tesla and Everyday Electric part is subject to a non-binding letter of intent. Electrek calls it the first concrete step in a 16.8 GW data-centre virtual power plant plan announced in June.

That plan is where the missing MWh matters. A data-centre operator buying peak relief needs sustained energy, and a record measured in megawatts for an unstated number of hours cannot be priced.

What would change my read

A CAISO or utility telemetry release giving MWh for Oct. 5 and 6 would settle the energy question. A Tesla statement that its 600 MW is a subset of Sunrun's 745 would confirm the 145 MW inference; a statement that it is additive would raise the combined total above 745 and make the headline number a Sunrun-only figure. The first PG&E dispatch of the roughly 21,000 devices, due this month, is the next dated test.