Eos Energy Enterprises Inc. shares advanced 12.2% in pre-market trading on Wednesday after the company unveiled a $350 million integrated clean energy development designed to provide uninterrupted power to Google LLC’s data centers.
The Mammoth Solar project, located in West Virginia’s Kanawha County, combines 86 megawatts of utility-scale solar power with 10 megawatts of Eos’s zinc-based long-duration storage system (Z3) and 70 megawatts of lithium-ion storage. The solar component is slated to begin commercial operations in 2028, while the Z3 storage system is projected to come online in 2030.
The project marks the first commercial-scale long-duration energy storage initiative in West Virginia and represents the first deployment of Eos’s domestically manufactured Z3 technology by Google. The initiative is structured to deliver power to Google’s data centers through the PJM Interconnection grid, a regional transmission organization serving 13 states and the District of Columbia.
Beyond energy supply, the project is expected to generate approximately 200 construction jobs and contribute roughly $4 million in local property tax revenue over its first two decades of operation. The total project value is estimated at $350 million.
Eos Energy’s shares had earlier reached a new 52-week low on September 1, trading at a significant discount before Wednesday’s pre-market surge. The broader market showed little movement, with the S&P 500 and Nasdaq remaining effectively flat during the session.
