Utility CPS Energy and IPP Eolian have entered into storage capacity agreements for two battery energy storage system (BESS) projects totalling 350MW of power capacity in the ERCOT, Texas market.
CPS Energy, which covers the city of San Antonio, has procured the BESS capacity as part of its Vision 2027 generation plan, and the deal builds on a 50MW agreement with Eolian in 2023.
The new agreement, called a storage capacity agreement (SCA), covers the 200MW Ferdinand BESS project and the 150MW Padua 2 BESS project. Both will be in South Bexar County, within which San Antonio is located, and are expected to come online in the first half of 2026.
Aaron Zubaty, CEO of Eolian, said the projects will be 4-hour duration, double the norm in the Texas, ERCOT market, where most projects are around two hours in duration.
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“Following on to the 50 MW Padua 1 project already under construction for CPS Energy, this additional 350 MW of four-hour duration battery energy storage will provide new dispatchable capacity to the San Antonio area by mid-2026, representing the single largest buildout of standalone battery energy storage in ERCOT to date and proving that deployment of fast and flexible energy storage resources at critical grid locations can bridge the many years until new transmission can be constructed to further support load growth and alleviate systemwide congestion,” Zubaty said.
CPS said having the storage resources within its services territory will contribute to overall grid resiliency and will benefit customers. The firm has 10MW of operational BESS in its portfolio, and these SCAs will increase that number by 400MW. The deals last 20 years.
Rudy D. Garza, president and CEO of CPS Energy said: “This is another step in executing on our Vision 2027 generation plan and we are excited about the benefits it will provide to our community through both reliability and economic development.”
Eolian’s Zubaty said the project locations were chosen ‘years ago’ to reduce the burden on the transmission system and enhance market operations, by being near load pockets and adjacent to retiring thermal generation units.
The projects will also contribute at least US$175,000 per year to CPS Energy sponsored activities and scholarships within the Greater San Antonio for a five-year period from the start of commercial operations.
The Texas energy storage market, often named after grid operator Electric Reliability Council of Texas (ERCOT), is the second-largest in the US after California. It is expected to have nearly 10GW of grid-scale BESS online by October 2022.
Just in the past week, a 200MW project changed hands between developer BMES and IPP Vitis, Spearmint Energy agreed to buy 1GWh of BESS from Sungrow for projects, and Enel commissioned a solar-plus-storage project, all in Texas.
