A major grid-scale energy storage project has officially entered construction in southeastern Bexar County, as the Alamo City Battery Energy Storage System (BESS) reaches its groundbreaking milestone in Texas.

 

The 120 MW / 480 MWh facility is designed to strengthen grid reliability across the San Antonio region by storing electricity during off-peak hours and dispatching it during periods of high demand. Once operational, the system will be capable of powering approximately 30,000 homes for up to four hours, providing critical support during peak load conditions.

 

The project is part of a broader expansion of battery energy storage infrastructure across Texas, where utilities are increasingly turning to large-scale storage systems to improve flexibility, manage demand spikes, and enhance overall grid stability.

Ownership

Under the project structure, OCI Energy developed and financed the facility and will retain ownership through a long-term storage agreement, while CPS Energy will operate the system to support electricity delivery across the San Antonio area.

 

Energy storage is playing an increasingly important role in utility planning as electricity demand continues to rise. Battery systems like the Alamo City project allow power to be shifted in time, helping reduce strain on generation assets during periods of peak consumption.

 

The project also brings together several major industry partners. ING is providing construction financing, LG Energy Solution Vertech is supplying battery technology, and Elgin Power Solutions is serving as the engineering, procurement, and construction contractor.

 

Once completed, the facility is expected to enter commercial operation in 2027, adding significant new capacity to support the reliability and resilience of the Texas electric grid.

Similar large-scale battery storage projects are also advancing in data center–driven energy markets, including Enbridge’s US$1.2 billion Cowboy Project in Wyoming, which combines solar generation and 200 MW of storage to support Meta’s data center demand while enhancing regional grid flexibility

Factsheet: Alamo City Battery Energy Storage System (BESS)

Project Name: Alamo City Battery Energy Storage System (BESS)
Location: Southeastern Bexar County, Texas, USA
Capacity: 120 MW / 480 MWh
Developer & Owner: OCI Energy
Operator: CPS Energy
Project Type: Standalone grid-scale battery energy storage system

Key Function

• Stores excess electricity when demand is low
• Supplies power during peak consumption periods
• Supports grid stability and peak load management
• Enhances reliability during high-temperature demand events

Expected Impact

• Ability to power ~30,000 homes for up to 4 hours
• Improved flexibility for the San Antonio electric grid
• Reduced strain on generation resources during peak demand

Project Structure

• OCI Energy developed and financed the project
• CPS Energy will operate the facility under a long-term storage agreement
• Electricity dispatch controlled by CPS Energy for regional grid support

Key Partners

• Financing: ING
• Technology Supplier: LG Energy Solution Vertech
• EPC Contractor: Elgin Power Solutions

Timeline

• Construction Start: May 19, 2026
• Expected Commercial Operation: 2027