California taps hundreds of thousands of home batteries to ease heatwave power surge
During a severe heatwave, California coordinated Tesla and Surun home battery systems to supply roughly 580 MW of electricity for three hours.
On September 9, an intense heatwave pushed California’s electricity demand to record levels as air-conditioners ran at full capacity. To counter the spike, Tesla and Surun coordinated the discharge of over 140 000 home-installed battery units, providing roughly 580 MW of power for three hours. This virtual power plant supplied enough electricity to cover every household in Sacramento County, serving about 1.5 million residents.
By replacing the output of two to three conventional gas plants, the operation avoided fuel combustion and demonstrated a scalable alternative for peak-load management. The initiative also offered financial incentives to homeowners who shared stored energy, and projections suggest similar deployments could save consumers billions of forints by 2028. A day later, Southern California Edison contributed additional battery-derived power, highlighting growing confidence in distributed storage solutions.
Why it matters
The event shows how residential batteries can quickly support the grid during extreme demand, reducing reliance on fossil-fuel plants.
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