# Sunrun Virtual Power Plant Supports Puerto Rico Grid for 18 Days Residential batteries provide critical grid stability during peak demand and extreme heat events. - **Source:** [Electrek](https://electrek.co) - **Published:** 2026-11-04 - **Topic:** [climate](https://brifing.si/c/climate) - **Original article:** - **On Brifing:** https://brifing.si/s/13159765-cb78-416e-824b-c5ec3a3bd110 ## Extended Grid Support Sunrun successfully utilized its virtual power plant network in Puerto Rico for 18 consecutive days throughout October. This deployment occurred during periods of unusually high temperatures, helping the local grid manage increased electricity demand. The network, which connects thousands of residential batteries, provides a flexible solution to prevent potential energy shortages. ## Scale of Operations The virtual power plant now includes nearly 70,000 batteries across the island, marking a significant expansion from previous years. Sunrun frequently delivers 45 megawatts of power for four-hour intervals during peak times. Since April, the company has dispatched energy more than 60 times to support the grid operator, LUMA, during shortfalls. ## Economic Context Puerto Rico faces some of the highest electricity costs in the United States, with residential rates averaging 26.36 cents per kilowatt-hour in August. This financial burden makes the adoption of home battery systems highly practical for residents. By participating in the grid-sharing program, homeowners can offset costs while maintaining essential backup power. ## Grid Reliability Challenges Reliability remains a persistent issue on the island, with customers experiencing an average of 36 hours without power in 2025, excluding major events. This figure represents a 19% increase compared to 2024. In contrast, mainland US customers typically face only two hours of outages annually, highlighting the severity of the local infrastructure crisis. ## Program Mechanics LUMA manages the Customer Battery Energy Sharing program, calling on aggregators like Sunrun when demand exceeds available generation. Sunrun automates the battery response, allowing homeowners to share a portion of their stored energy while retaining control over their backup reserves. The company earns recurring revenue for operating this distributed energy network. ## Capacity Limitations Despite the program's growth, current capacity is not sufficient to prevent every rolling blackout. Participating aggregators noted in an April regulatory filing that some supply gaps exceed the program's roughly 50-megawatt, four-hour capacity limit. Consequently, there is an ongoing effort to enroll more customers to cover larger, more frequent generation shortfalls. ## Rapid Network Growth Sunrun's participation in the local market has surged, growing from approximately 4,000 customers in 2024 to over 30,000 in 2025. This rapid scaling positions the company as the largest aggregator within the Customer Battery Energy Sharing program. Such growth reflects a broader shift toward decentralized energy resources to bolster island-wide power stability. ## Future Outlook The integration of residential batteries serves as a vital bridge while the island works to improve its aging power infrastructure. By utilizing existing equipment rather than waiting for new power plants, the grid gains immediate, scalable capacity. Future success depends on continued enrollment and the ability to manage larger, more complex energy gaps. ## Sources covering this story - https://electrek.co/2026/11/04/puerto-rico-tapped-sunruns-home-batteries-for-18-straight-days/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._