Ørsted Energizes 500 MWh Old 300 Battery in Needville, Texas

A 250 MW/500 MWh battery has entered commercial operations at Needville, Texas, where Ørsted already runs a 430 MW solar plant on the same site, pv magazine reported.

The unit, called Old 300 Storage, sits inside the ERCOT market and dispatches on its own schedule rather than as one hybrid resource with the neighboring Old 300 Solar plant, which started generating in 2024. Separate operation lets the battery set its own charge and discharge pattern in the market.

Tesla supplied the hardware. The installation is built from Megapacks produced at the manufacturer's plant in Lathrop, California.

Melissa Peterson, president of Ørsted Americas Onshore, tied the milestone to system reliability, saying the project strengthens "grid reliability by providing additional resources to Texas grid operators".

Ørsted estimates that the solar and storage assets at Old 300 will together deliver roughly USD 110 million in property tax revenue to the surrounding area over their operating lives.

The start-up lifts the developer's operating onshore fleet in the United States to 6 GW. That total spans the company's generating and storage assets already in service, with the Needville battery the newest addition.

The 500 MWh rating against 250 MW of power gives the system two hours at full output. Charging is not confined to the adjacent array, since the battery answers to ERCOT dispatch instructions rather than to the solar plant's production profile.

Commercial operations at the battery follow two years of solar generation at the same location. The pairing of a 430 MW array with a 250 MW battery on one site puts more energy capacity behind a single interconnection point than either asset would carry alone.