Sunrun says its Puerto Rico battery fleet doubled to over 60,000 customers

Sunrun's home-battery network in Puerto Rico now counts more than 60,000 customers, double the more than 30,000 enrolled in 2025, the company said on November 3. The fleet of nearly 70,000 batteries delivers 45 MW of dispatchable power for four hours at a time, Sunrun says, and has been dispatched more than 60 times since April, including 18 consecutive days beginning October 13 during unseasonably hot weather.

The batteries sit in the Customer Battery Energy Sharing (CBES) program of LUMA, the operator of Puerto Rico's transmission and distribution system, which lets customers make power from their residential batteries available to the grid during emergency conditions. Sunrun calls itself the program's largest aggregator. LUMA said on July 6 that over 90,000 CBES customers had helped it add an average of 75 MW in 2026 to reduce the impact of generation shortfalls. Sunrun's release quotes LUMA statements from June and July crediting home-battery energy with helping "maintain system stability and prevent outages that would have affected thousands of customers."

Each battery gives up only a little. By our arithmetic, 45 MW across nearly 70,000 batteries is about 0.65 kW apiece. Sunrun says most participants share a small portion of their capacity, keep the rest for their own backup, and are paid for what they share. Brattle's October report on home virtual power plants, covered here in October, says aggregators enroll 30% of a battery's installed capacity, and credits Sunrun and Tesla with scaling CBES participation sevenfold in just over a year by auto-enrolling new third-party-owned batteries, with an opt-out.

Sunrun CEO Mary Powell pointed the story north: "What began in Puerto Rico out of necessity for family resilience has become a vital blueprint for the U.S. mainland, where severe weather and the proliferation of AI data centers are demanding new energy solutions." In a release about keeping an island's lights on, her next sentence offers capacity "for hyperscalers looking to come online." The mainland picture is on our virtual power plants reference page.