U.S. Mammoth Solar Project to Build 86 MW Solar with 380 MWh Storage by 2028

en.Wedoany.com Reported - The Mammoth Solar project in Kanawha County, West Virginia, will combine 86 megawatts of solar power with 380 megawatt-hours of battery storage, developed in partnership by MN8 Energy, Eos Energy Enterprises, and Google to provide dispatchable power to Google data centers beyond daylight hours.

The project's storage system comprises conventional lithium-ion batteries and a 10 MW/100 MWh zinc-based long-duration battery developed by Eos. Eos's zinc battery uses an aqueous zinc-based chemistry, designed for long-duration applications with a 10-hour storage capacity; the lithium-ion batteries handle short-duration storage, typically used to shift solar output over a period of hours.

Solar generation, the rapid response of lithium-ion batteries, and the long-duration discharge of zinc batteries will operate in tandem: solar power generated during the day is stored in batteries and released after sunset or when electricity demand rises, so the plant's output no longer depends entirely on real-time sunlight.

As scheduled, the solar generation portion of Mammoth Solar will enter commercial operation in 2028; the lithium-ion storage is slated to come online in 2029; and the zinc-based batteries with longer discharge duration are expected to be operational by 2030.

The plant will be built on a reclaimed coal mine site. MN8 Energy estimates the project could bring up to $350 million in capital investment and is expected to create approximately 200 jobs during construction; over the first 20 years of operation, it is projected to generate about $4 million in property tax revenue for Kanawha County and local schools. The plant's electricity will connect to the PJM grid. PJM is one of the largest electricity markets in the United States, and as more renewable energy comes online, dispatchable clean capacity of this kind not only meets Google data centers' electricity demand but also helps the grid cope with growing power consumption.

Google stated in the project description that such solutions must simultaneously meet data center capacity needs and drive the energy system toward a cleaner, more economical transition. For Eos Energy Enterprises, this project also marks Google's first deployment of its U.S.-manufactured Z3 technology and is the first project under the supply agreement previously announced by MN8 and Eos.