The next great battery is made of rust. In Weirton, West Virginia, a steel town building its second act, Form Energy is manufacturing batteries whose entire recipe is iron, water and air. When the grid has spare power the battery turns rust back into iron; when the grid needs power it lets the iron rust again, breathing out electricity as it goes. The result stores energy for one hundred hours at a stretch, compared with about four for the lithium batteries in most grid storage today, with no scarce metals, nothing toxic, and materials among the cheapest on Earth.
The world has noticed. In February, Google and the utility Xcel Energy announced a 300 megawatt iron air system in Minnesota, able to hold thirty gigawatt hours, the largest battery energy storage project ever announced anywhere. Long, still, cloudy stretches are the hardest argument against wind and solar power, and a battery that can carry a town through four windless days at a time quietly answers it. The future of clean energy may look less like a moonshot and more like a warehouse full of patient, rusting iron, keeping the lights on.
Our short take: Form Energy's iron air batteries are made at Form Factory 1 in Weirton, West Virginia; the Google and Xcel Energy project was reported by Utility Dive and Tech Startups, February 2026.