Google-backed West Virginia solar adds 10 MW/100 MWh zinc LDES for PJM grid

MN8 Energy, Google, and Eos Energy Enterprises are teaming up on a new clean energy project in Kanawha County, West Virginia, combining utility-scale solar with both lithium-ion storage and Eos’ zinc-based long-duration energy storage for the PJM grid. For data center operators tracking how utilities and developers are trying to match renewable generation to round-the-clock load, the multi-technology build is explicitly aimed at delivering dispatchable capacity aligned to Google’s regional data center demand, including a planned project in West Virginia.

Owned and operated by MN8, the portfolio combines 86 MW of solar, 70 MW/280 MWh of lithium-ion energy storage, and 10 MW/100 MWh of Eos’ Z3 zinc-based long-duration energy storage. MN8 describes the build as its Mammoth Solar project, designed as a single integrated resource that can shift intermittent solar output into a dispatchable capacity product. The solar portion is expected to reach commercial operation in 2028, with the lithium-ion system expected to follow in 2029 and the long-duration storage system in 2030.

From an engineering perspective, the key detail is the duration mix: the Z3 system is sized at 10 MW/100 MWh, or 10 hours of storage, while the lithium-ion block (70 MW/280 MWh) pencils out to four hours. That combination targets different grid services and operating windows, with longer-duration discharge intended to extend solar availability deeper into the day than shorter-duration batteries typically can. MN8 also calls it the first commercial-scale long-duration energy storage deployment in West Virginia.

Under the agreement, Google will purchase the energy, capacity, and clean energy attributes from the project. Google’s Lucia Tian, Director, Advanced Energy Technologies, said the collaboration “aims to deploy a smart portfolio of round-the-clock technology solutions to help power our digital infrastructure, while creating meaningful economic benefits for West Virginia.”

Eos says this is Google’s first project using its American-made Z3 technology and the first project under a previously announced MN8-Eos Master Supply Agreement. Nathan Kroeker, Chief Commercial Officer at Eos, said, “Our work with Google is focused on deploying American-made long-duration storage where it solves real grid reliability challenges.”

The project site is described as a reclaimed coal mine in West Virginia. MN8 estimates up to $350 million in capital investment, about $4 million in property tax revenue for the county and local schools over the first 20 years of operations, and about 200 construction jobs, plus additional full- and part-time roles during operations.

MN8 Energy, Eos Energy Enterprises, and Google did not provide pricing terms for the power purchase arrangement.