Repurposed EV batteries now delivering 28 MWh of grid services to ERCOT

A company called B2U Storage Solutions has built a new battery storage project near San Antonio that runs on used electric vehicle (EV) batteries. The project, called Bexar Martinez, is now sending 28 megawatt-hours of power to the Texas grid, operated by ERCOT, in the CPS Energy service area. Instead of scrapping EV batteries once they no longer hold enough charge for driving, B2U reuses them in large storage systems that help balance electricity supply and demand.

With this project, B2U now runs 50 megawatt-hours of this kind of storage in Texas, plus more in California. Across both states, the company manages over 5,000 repurposed EV batteries and about 100 megawatt-hours of storage total. It plans to add more than 50 additional megawatt-hours in Texas over the next six months, aimed at supporting one of the fastest-growing parts of the state's power grid.

This isn't a program homeowners can sign up for, but it points to where grid-scale storage is headed. Projects like this help utilities handle rising electricity demand at lower cost, which can factor into local electricity prices and grid reliability over time. The project also qualifies for a domestic content bonus under the federal Investment Tax Credit (ITC), a tax incentive tied to using US-made components, and has secured outside financing, suggesting this kind of reused-battery storage is becoming a proven, bankable technology rather than a one-off experiment.