How Texas became the hottest grid battery market in the country

On the warm spring night of April 28, Houston had a problem.

Denizens of the most populous region in Texas were cranking up air conditioning to beat the early burst of summery heat. Texas’ nation-leading solar fleet had wound down for the night, passing the baton to the nation’s largest fleet of fossil-fuel-burning plants to keep all those air conditioners going. Gas and coal plants were pumping out 40 gigawatts of power — but another 27 gigawatts of thermal plants were offline, undergoing maintenance ahead of the bustling summer season.

That scheduled maintenance exposed a vulnerability in the gas fleet, which politicians in Texas and elsewhere frequently tout as being unfailingly dependable. ​“They’re reliable when they’re on and they have fuel, which is not always the case,” noted Joshua Rhodes, an energy researcher at the University of Texas at Austin.

That unlucky mix of unseasonable warmth and power plant maintenance threatened the supply of power for the 26 million customers hooked up to the state’s uniquely isolated grid, which is run by the Electric Reliability Council of Texas, or ERCOT.

Fortunately, the grid operator had a new tool it could fire off in an instant.

Enormous, digitally controlled batteries across the Lone Star State rapidly injected 2 gigawatts of power into ERCOT’s wires just before 8 p.m., staving off potential power shortfalls and lowering electricity costs for customers.

Aaron Zubaty, CEO of Eolian Power, was watching these events closely. His company owns and operates some of the biggest batteries in Texas, and he saw April 28 as a test for the ascendant Texas energy storage industry.

“This was the largest instantaneous amount of energy storage deployed to date in the Texas market, but nevertheless is a record that will be substantially exceeded this summer as more energy storage capacity is commissioned in the coming months,” he noted at the time.

It didn’t take long for that prediction to come true. On May 8, evening demand was climbing and conventional power plants totaling nearly 22 gigawatts of capacity were offline. Just before 8 p.m., the batteries surged more than 3 gigawatts onto the wires, beating the April 28 record by 50 percent.emphasized text