Eolian Starts 50MW Padua 1 BESS for CPS Energy in Bexar County

What Was Built

Padua 1 is a 2-hour duration BESS sited at a critical substation adjacent to the JK Spruce and retiring Braunig power plants in Bexar County. CPS Energy launched the original RFP seeking 50 MW of battery storage in 2020; Eolian signed the storage capacity agreement in 2023. The system connects directly to the CPS Energy grid and charges during periods of excess electricity supply, then deploys within seconds during peak system cost and demand hours. That sub-second ramp rate provides load balancing support that conventional generation assets cannot match.

Padua 1 is the first phase of the larger Padua Grid complex. The full complex — adding Padua 2 (150 MW/600 MWh) and Ferdinand (200 MW/800 MWh) — is projected to total 400 MW and nearly 2 GWh when complete in early 2026, making it the largest battery energy storage deployment in Texas.

Why It Matters

CPS Energy serves San Antonio, a city with a fast-growing population and rising electricity demand. Padua 1 addresses a pinch point in ERCOT south-to-north transmission flows: the substation location governs critical flows that have repeatedly strained the grid during extreme heat events. Battery storage at this location allows existing transmission lines to be used more efficiently, deferring costly new wire infrastructure.

“Padua 1 is a major step forward for our utility and our community,” said Rudy D. Garza, President and CEO of CPS Energy. “It is the first energy storage project as part of our diverse generation plan to come online, and it sets the tone for what is ahead. Battery storage strengthens our ability to continue to serve our customers reliably now and in the future.”

Aaron Zubaty, CEO of Eolian, framed the project in grid-wide terms: “The overall Padua Grid battery energy storage complex, which will total 400 MW and nearly 2 GWh when completed in early 2026, will be the largest battery energy storage deployment in Texas when completed. Battery energy storage projects of this scale enable the efficient utilization of existing transmission resources and are the lowest-cost and fastest solution to meeting the strategic need to grow electricity production.”

Critical Perspective

Padua 1 covers only the first 50 MW of what CPS Energy requires. The utility still needs Padua 2 and Ferdinand to reach the capacity levels committed under Vision 2027 — both are under construction but not yet online. Texas saw high-profile battery storage fire incidents at other sites in 2025, raising questions about large-scale BESS safety protocols that Eolian and CPS Energy have not publicly detailed for the Padua complex. The community benefits commitment of $175,000 annually for five years is modest relative to the scale of this private infrastructure investment. A $50,000 donation to the Residential Energy Assistance Programme in 2024 preceded commissioning but does not guarantee ongoing direct bill relief for low-income customers in the San Antonio area.

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