Eos Energy Enterprises is walking a zinc-based long-duration battery into a Pentagon program. The Pittsburgh company said on Wednesday it was awarded a multi-million-dollar contract to supply its Z3 storage system to Golden Dome for America, the missile-defense architecture President Donald Trump has framed as a national priority.
A defense debut for zinc chemistry
The award, announced from Senator Dave McCormick's Defense and National Security Summit in Carlisle, Pennsylvania, calls for Eos to install its Z3 platform first as an initial prototype at a critical installation and to scale from there as national defense needs evolve. The Z3 is a non-flammable aqueous zinc chemistry — Eos calls it Znyth — built for 4-to-16-plus-hour duration. That is well beyond the operating window of most lithium-ion systems at defense sites, which are typically sized for minutes to a few hours.
Domestic content is the story
Eos says the Z3 is roughly 91% U.S.-sourced and its supply chain is Section 842 NDAA and FEOC-compliant, both of which are prerequisites for defense procurement. The batteries are manufactured at Eos's Thorn Hill facility in the Pittsburgh region, where a second production line has just come online and where the company is working toward 8 GWh of annual capacity in Allegheny County. "The Golden Dome should be built on American technology," Senator McCormick said in the announcement.
Why long-duration storage on a defense shield
Golden Dome is intended to knit together a mix of sensors, interceptors and command nodes. That posture only works if the underlying installations stay live through grid disturbances and directed attacks on power infrastructure. Long-duration storage lets a site ride out extended blackouts without hauling in diesel or leaning on precious lithium-ion cells that could be reallocated to combat platforms. It also gives operators a hedge against the growing strain on U.S. grids from AI data centers and new fabs — the same trend driving nuclear-backed data center bets and gigafactory expansions on the East Coast.
Where Eos goes from here
Eos CEO Joe Mastrangelo said the award validates the U.S. manufacturing bet the company has been making for years — the same bet that put the Z3 platform inside a crowded market for utility-scale batteries earlier this year. If the prototype install performs, Eos becomes a viable multi-year contractor for the Department of War, in the same class as more established defense storage suppliers — with the added political tailwind that the batteries come out of Pennsylvania rather than through Chinese suppliers.
Reporting based on coverage from Eos Energy Enterprises, GlobeNewswire, Energy-Storage.News and Reuters.