Energy Vault Holdings has begun construction of its 150 MW / 300 MWh SOSA Battery Energy Storage System in Madison County, Texas, marking the first Asset Vault project to reach on-site construction. Acquired from Savion in Q4 2025, the project is backed by Orion Infrastructure Capital and uses Energy Vault’s third-generation B-VAULT™ DC platform. Designed for ERCOT market services, SOSA targets commercial operation by Q2 2027 and underpins Energy Vault’s growing asset-backed revenue strategy.
California- based Energy Vault Holdings, Inc., has commenced construction of the 150 MW / 300 MWh SOSA BESS in Madison County, Texas. Construction activities began in Q4 2025 following the project’s acquisition from Savion, a subsidiary of Shell plc, under Energy Vault’s Asset Vault “Own & Operate” platform.
The SOSA Energy Center represents the first project to move into on-site construction under Energy Vault’s Asset Vault investment program, which is supported by a USD 300 million preferred equity investment from Orion Infrastructure Capital. With this milestone, Energy Vault’s total portfolio of assets under operation and construction has exceeded 340 MW. The company reported total cash and liquidity of more than USD 100 million at the end of Q4 2025, reflecting a quarter-on-quarter increase of approximately 65%.
The project is designed around Energy Vault’s third-generation B-VAULT™ DC battery platform and has been structured to meet safe harbor and Foreign Entity of Concern compliance requirements. The project advanced to construction readiness following completion of land control arrangements, environmental clearances, and executed grid interconnection agreements. Energy Vault is responsible for EPC execution and long-term servicing, with operations managed internally.
The 150 MW / 300 MWh system is intended to provide grid services in the ERCOT market, including energy arbitrage and reliability support, as thermal generation retires and variable renewable generation continues to expand across Texas. The project is targeting commercial operation by Q2 2027 and is expected to operate under a 6–8-year off take agreement, which is currently under advanced negotiations with investment-grade counterparty.
Over its technical life, the SOSA Energy Center is projected to generate more than USD 350 million in total revenue, equating to approximately USD 17–20 million in recurring annual revenues, contributing to Energy Vault’s asset-backed revenue model.