Commission approves 200 MW, two-hour utility-scale battery to bring bulk energy storage to Austin�

The Electric Utility Commission voted July 20 to advance a utility-scale battery agreement to City Council after staff described the project as a 200-megawatt resource with two-hour duration (400 MWh total). Pat Sweeney, interim vice president for energy market operations, said the installation is a centralized, utility-scale asset that Austin Energy will dispatch.

"This is 200 in 2 hours," Sweeney said, describing the project's size and confirming it is comparable on total energy to a previously considered OCI battery. He told commissioners that while the earlier OCI project had been planned for a different location, the economics after adjusting for size were "very, very comparable." The project location is known to staff but withheld from the public record for commercial and security reasons.

Commissioners pressed staff on operational flexibility and whether the battery would reduce reliance on proposed peaker plants. "Can this battery be discharged at different rates?" one commissioner asked. Sweeney replied the resource can be dialed back and spread over more hours and that Austin Energy's control room will have dispatch authority.

Staff said the project contributes to multiple grid objectives — price stability within the service area, ancillary services and demand response — but that peaker plants address different system needs and the battery alone is not a one-to-one substitute. Sweeney said certain contractual limits (such as cycle limits) will apply to battery agreements.

Public commenters had earlier urged the commission to scrutinize battery contract economics. Paul Robbins, vice chair of the city's Resource Management Commission and an energy-sector veteran, told the commission he had concerns about whether there are enough "arbitrage hours" for the utility to buy low and sell high and urged commissioners to press for transparency.

The commission moved and approved the battery item without a roll-call tally recorded in the transcript excerpt. The item will proceed to City Council for final action.