Developer targets 2027 completion for grid‑scale storage facility
Energy Vault Holdings Inc. has begun construction on the SOSA Energy Center, a 150‑MW/300‑MWh battery energy storage project in Madison County, Texas. The project advances the developer’s owned‑asset strategy and marks the fourth facility to move into construction under its Asset Vault platform, said the company.
The site, originally developed by Shell subsidiary Savion, was acquired by Energy Vault in late 2025. Commercial operation is targeted for the second quarter of 2027.
Madison County is located roughly 90 miles northwest of Houston along the Interstate‑45 corridor, positioning the project within reach of one of the state’s largest power load centers. Although located there, Energy Vault says the facility will operate in the northern market of ERCOT, the statewide grid operator, which covers the Dallas–Fort Worth area and surrounding North Texas counties.
“Breaking ground on the SOSA Energy Center so quickly after acquisition demonstrates the velocity with which we are executing and growing Energy Vault’s Asset Vault platform,” said Robert Piconi, chairman and CEO. He added that the project “underscores our strategic commitment to the Texas ERCOT market, one of the most dynamic energy markets in the United States.”
The project will use Energy Vault’s third‑generation B‑VAULT DC battery system, a utility‑scale, DC‑coupled platform built for grid storage. Company documentation describes a modular enclosure that supports different battery and inverter configurations and is operated through the firm’s VaultOS control software. The system is engineered to provide grid‑balancing support and sustained long‑term operation.
The company is in advanced talks on a multi‑year offtake agreement with an undisclosed investment‑grade buyer and plans to self‑perform engineering, procurement, construction and long‑term service work to maintain control throughout the project’s life cycle.
“Texas continues to lead the nation in renewable energy adoption and grid modernization, making it a cornerstone market for our growth strategy,” Piconi said.
With SOSA moving into construction, Energy Vault now has more than 340 MW of storage assets operating or underway, with additional projects slated to come online in 2027 and 2028.
