Google backs zinc battery storage at reclaimed West Virginia coal mine
Google will buy power from MN8 Energy’s 86 MW Mammoth Solar project in West Virginia, including Eos Energy’s first 10 MW zinc battery deployment for Google.
Photo by Mark Stebnicki on Pexels
Google, MN8 Energy and Eos Energy Enterprises announced on September 2, 2026 that Google will purchase the energy, capacity and clean energy attributes of the “Mammoth Solar” project, an 86 megawatt solar installation built on a reclaimed coal mine in Kanawha County, West Virginia, that will pair the solar array with two battery systems, including Eos’s first zinc-based storage deployment for Google. MN8 Energy will own and operate the project, which is intended to help supply Google’s data centers in the region, including a planned facility in West Virginia.
Two storage technologies on one site
The project combines 86 MW of utility-scale solar with 70 MW/280 MWh of lithium-ion battery storage and 10 MW/100 MWh of zinc-based long-duration storage using Eos’s Z3 technology, built on the company’s Znyth aqueous zinc battery chemistry. The companies describe it as the first commercial-scale long-duration energy storage deployment in West Virginia, Google’s first project using Eos’s Z3 technology, and the first project delivered under the previously announced MN8-Eos Master Supply Agreement.
Eos Chief Commercial Officer Nathan Kroeker said the zinc storage is designed to extend how long the site’s clean generation remains useful to the grid: “The grid needs more from every megawatt of new generation. Our work with Google is focused on deploying American-made long-duration storage where it solves real grid reliability challenges. Z3 extends the value of clean generation across more hours, strengthens the overall portfolio, and delivers more dependable capacity when it’s needed most.”
| Component | Capacity | Technology |
|---|---|---|
| Solar array | 86 MW | Utility-scale photovoltaic |
| Lithium-ion storage | 70 MW / 280 MWh | Conventional short-duration battery |
| Zinc-based storage | 10 MW / 100 MWh | Eos Z3 (Znyth aqueous zinc chemistry) |
Source: MN8 Energy, Google and Eos Energy Enterprises, September 2, 2026.
Timeline and site
Under the current schedule, the solar array is expected to reach commercial operation in 2028, the lithium-ion storage in 2029, and the zinc-based long-duration storage in 2030. The companies did not name the specific former coal mine or disclose remediation details, describing the site only as “a reclaimed coal mine in West Virginia” in a community with “a long energy history.” MN8 estimates up to 350 million dollars in capital investment, roughly 4 million dollars in property tax revenue to the county and local schools over the project’s first 20 years, and about 200 construction jobs plus additional operating roles.
Google Director of Advanced Energy Technologies Lucia Tian linked the deal to the company’s data center power needs: “At Google, we’re committed to backing solutions that both serve our data center capacity needs and accelerate progress toward cleaner, more affordable energy systems.” MN8 Energy President and CEO Jon Yoder said the project paired technologies to match Google’s specific load profile: “Because Google was willing to pair next-generation storage with utility-scale solar, we could engineer proven and emerging technologies into one dispatchable resource.”
MN8 Energy, founded within Goldman Sachs and independent since 2022, is headquartered in New York with offices in South Florida, Dallas and Madrid, Spain. The company says it operates or has under construction more than 4 gigawatts of assets across 29 states, serving more than 200 customers including AI and hyperscale technology companies. This is not Google’s only recent solar-plus-storage deal: the company broke ground with Cypress Creek Energy on the Steel River Energy Center, a solar and battery project in Arkansas the companies describe as the largest of its kind in the US.
Background
Eos Energy Enterprises is a US manufacturer of zinc-based long-duration energy storage systems, headquartered and manufacturing in Pittsburgh, Pennsylvania. Zinc-based batteries are one of several non-lithium storage technologies developers are testing for multi-hour and multi-day grid balancing, an area that has drawn other recent research, including a flowing zinc slurry battery from Fudan University and the Chinese Academy of Sciences that ran for 5,128 hours in a Nature Energy-published test. The Mammoth Solar project marks Eos’s entry into supplying Google directly and its first deployment under the MN8-Eos supply agreement, extending a broader trend of pairing solar generation with longer-duration storage to meet the steady, round-the-clock power demand of data centers.
Sources: MN8 Energy, Google and Eos Energy Enterprises (GlobeNewswire release); Utility Dive
Featured image: photo by Mark Stebnicki on Pexels (free Pexels license).
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I specialize in sustainability education, curriculum co-creation, and early-stage project strategy. At WINSS, I craft articles on sustainability, transformative AI, and related topics. When I’m not writing, you’ll find me chasing the perfect sushi roll, exploring cities around the globe, or unwinding with my dog Puffy — the world’s most loyal sidekick.
