Maja Hitij/Getty Images Tesla is building a giant 100-megawatt battery to plug into Texas' power grid, Bloomberg first reported. The project in Angleton, Brazoria County, would aim to help stabilize the area's energy supply. In February, devastating blackouts left millions of Texans without power and clean drinking water. Tesla is making a giant battery to plug into Texas' power grid, Bloomberg reported on Monday. Gambit Energy Storage, a subsidiary of the electric-car giant, is developing a battery-energy-storage project in Brazoria County, Texas. The system is registered with the Electric Reliability Council of Texas, the state's power-grid operator. An ERCOT filing from August gave the project an expected commercial opening date of June 1, 2021, and said it has capacity to store 100 megawatts of energy.