B2U Storage Solutions has begun commercial operations at its Bexar Martinez battery storage project near San Antonio, bringing 28 MWh of grid services to ERCOT using repurposed electric vehicle batteries.
What is the Bexar Martinez project?
The Bexar Martinez battery energy storage system is located in Bexar County and operates within CPS Energy's service territory. B2U said the project is built entirely with repurposed EV batteries, giving batteries that have reached the end of their automotive use a second life as grid-scale storage.
The project is B2U's second Texas site using its patented battery storage cabinets and repurposed EV batteries. The company said its Texas portfolio now provides more than 50 MWh of grid services to ERCOT.
B2U said the project will support grid reliability in one of ERCOT's fastest-growing regions as electricity demand increases. The company says repurposing EV batteries can reduce waste and provide a lower-cost approach to energy storage.
B2U CEO Freeman Hall: "Bexar Martinez proves that second-life batteries can deliver reliable, cost-effective grid services at scale."
ERCOT has continued expanding its integration of battery storage resources, including through its Real-Time Co-optimization Plus Batteries market design, which began operating in December 2025.
What comes next for B2U?
B2U said it manages more than 5,000 repurposed EV batteries across Texas and California and operates roughly 100 MWh of storage. The company expects to deploy more than 50 additional MWh of storage in ERCOT over the next six months.
The company also said Bexar Martinez and its other projects qualify for the domestic-content bonus under the federal Investment Tax Credit and have received third-party financing.
