Google invests in zinc battery storage at West Virginia solar project

Google is supporting a new energy initiative in West Virginia that will employ zinc battery technology for renewable energy storage. The $350 million Mammoth Solar project will be built on a 500-acre site previously used for coal mining.

The project will sell energy to Google, which aims to achieve 24/7 carbon-free energy. This marks the first instance of the tech giant relying on zinc batteries, an emerging long-duration technology capable of storing electricity for up to 10 hours. While zinc batteries will form a small portion of the overall capacity, they will be used to test long-duration energy storage.

Jon Yoder, president and CEO of MN8 Energy, Google's partner in the venture, explained that lithium-ion batteries are suitable for short-term storage (around four hours) but are too costly for longer storage needs. Zinc batteries offer a more cost-effective solution for extended storage periods and boast high round-trip efficiency.

"We chose to support Eos's batteries because the chemistry relies on Earth-abundant materials—zinc and bromine—and a more resilient supply chain than traditional lithium-based systems," said Campbell Howe, advanced energy program manager at Google. Howe added that Eos's manufacturing facility in Pennsylvania supports job creation in the Appalachian region.

Construction of Mammoth Solar is slated to begin in 2027. The project will include 86 megawatts of solar panels by 2028, the addition of 70 megawatts of lithium-ion batteries by 2029, and 10 megawatts of zinc batteries by 2030. This combination is expected to significantly enhance the ability to supply power 24 hours a day.