The big picture:

The hardware did exactly what it was supposed to do. Sunrun and Tesla discharged their fleets at the request of the California Energy Commission (CEC) and local utilities [1].

The trigger was a simple price signal. Once the California Independent System Operator (CAISO) saw its day-ahead price cross $200 per megawatt-hour, the call went out [1]. Sunrun alone has more than 120,000 home batteries signed up [1].

But this record measures a corporate pool, not a single home. The Demand Side Grid Support (DSGS) program pays the company that bundles those batteries — the aggregator — a set sum for the capacity it can prove each month. The homeowner’s cut comes from somewhere else.

My read starts with the state’s price list. A four-hour battery setup earns $9.00 per kilowatt (kW) each month in May, $19.20 in September, and $10.50 in October. That totals $82.80 per kW for the season [2].

A two-hour setup earns $62.10 [2]. Those are the aggregator’s numbers, before this season’s 30% state bonus [2].

The rulebook leaves the garage payout to a private contract. The state requires that aggregators of a virtual power plant (VPP) — the pool itself — allocate payouts to owners according to terms the two sides agree to [2]. The state sets a price for the pool, and leaves the rest to a contract a homeowner signs once.

That split explains why the record and the money are two different stories. A battery’s rating is what the pool can deliver, and the pool is what gets paid. An owner reading about “745 MW” sees proof of a working machine, while the company sees delivered power against a known rate card.

Timing makes this gap worse. Lawmakers put $27 million into the program in June to fund it through the end of the year [3]. The October heat wave may have burned through that cash, and the session ended with no new money for 2027 [3].

The law authorizes the program to run until 2032, but the state writes the check one season at a time [2]. Sign-ups are just as strict. The 2026 season limits entry to pool managers that took part in October 2025 [2].

A homeowner who bought a battery this year has no new door to walk through. Eight days after the record, Pacific Gas and Electric (PG&E) sent next-day shutoff notices to about 70,000 customers across 29 counties [4]. The Public Safety Power Shutoff (PSPS) could have cut power from 14 to 17 October [4].

In that single week, the same home battery acted as a grid power product and a personal backup tool. The two jobs pay differently and fail differently.

By the numbers

  • 745 MW — One evening’s record: Home batteries delivered 669 MW on 5 October and 745 MW on 6 October, against 580 MW on 9 September and 539 MW in July 2025 [1].
  • $82.80 per kW — Aggregator season rate: The base payout for a four-hour class from May through October, before a 30% bonus [2].
  • 120,000 batteries — Sunrun’s state fleet: The signed-up unit count driving the company’s share of the record [1].
  • 70,000 customers — Shutoff warning volume: PG&E’s 29-county outage notice for 14–17 October, which included 3,920 Medical Baseline customers [4].

What I’d watch:

  • The contract split: The state’s rate card is public, but the household’s share is not. I am watching what homeowners actually get against that $82.80 ceiling, and whether any company prints the exact split before sign-up.
  • The reserve floor: One active pool manager caps each drain at two hours, holds a 20% floor on the battery, and skips events during local outages [10]. These rules decide if a grid event leaves a house in the dark. The program leaves these limits to the contract rather than the state rulebook [2].
  • The 2027 check: A program that pays for power and then stops leaves the hardware in place and the income gone. I’m watching for an early budget fix, a new setup from the California Public Utilities Commission (CPUC), or nothing at all [3][9].
  • The safety case: The Electric Power Research Institute (EPRI) shared failure data for grid-scale batteries on 5 October. The United States failure rate fell more than 97% from 2016 to 2025 while installs rose 250-fold [5][6]. I’d watch how the industry uses this, since the lead author admits the data set is too small to model perfectly [6].

The catch

The other side of this trade is stronger than it first looks. A battery bought for outages does not need a grid payment to earn its keep. Backers point to a Brattle Group estimate of about two dollars of grid value for every dollar spent on these pools [3][9].

They argue the October record proves the home fleet actually shows up when called. My read is narrower than the headline. That 97% decline covers large commercial sites, not the 13.5 kilowatt-hour box sitting in a garage [5][6].

The safety record quoted for home units belongs to a different group of machines run by different people. The home is also the only side of this trade without a printed price. The state prices power to the aggregator, the aggregator prices the contract, and the owner pays in battery cycles.

California proved a pool of home batteries can carry a large grid event, but it left the payment side half-built. That is why the next five weeks matter more than the last five.

At a glance

  • The Big Shift: Home batteries in California pushed a record 745 MW into the grid on 6 October, but the state program funding these grid events ends on 31 October with no 2027 budget.
  • Why It Matters: The state pays the aggregator a set rate per kW of power and leaves the homeowner’s cut to a private contract, meaning the record reflects the pool’s success rather than the owner’s return.
  • What I’d Watch:
  • The contract split: The exact share of the $82.80 per kW season rate that reaches the owner, and whether companies disclose it upfront.
  • The reserve floor: Contract terms that cap drain times, hold a minimum battery charge, and carve out local outages.
  • The 2027 check: Whether an early budget fix or a new CPUC rule replaces the current seasonal pool.
  • The Catch: The 97% drop in battery failure rates covers large grid sites, not home units, and the homeowner remains the only participant without a guaranteed, public price.

Related reading

Sources

[1] https://investors.sunrun.com/news-events/press-releases/detail/384/sunrun-leads-record-grid-dispatch-delivering-enough-energy [2] https://dsgs.olivineinc.com/faq [3] https://www.renewableenergyworld.com/energy-business/policy-and-regulation/california-left-the-nations-largest-vpp-in-limbo-whats-next-factor-this-policycast [4] https://investor.pgecorp.com/news-events/press-releases/press-release-details/2026/High-Winds-Dry-Conditions-Mean-PGE-May-Need-to-Proactively-Turn-Off-Power-for-Safety-Wednesday-Evening-in-Portions-of-Twenty-Nine-Counties/default.aspx [5] https://www.epri.com/research/products/000000003002034920 [6] https://www.canarymedia.com/articles/batteries/us-grid-batteries-fire-risk [7] https://www.voltus.co/press/google-voltus-1gw [8] https://www.energy.ca.gov/data-reports/energy-almanac/california-electricity-data/california-energy-storage-system-survey [9] https://www.canarymedia.com/articles/virtual-power-plants/california-guts-biggest-virtual-power-plant [10] https://www.franklinwh.com/PDF/20250403%20-%20DSGS%20Participant%20Terms%20%20Conditions%20-%20FranklinWH.pdf