Iron and Air Fuel the Next Great Battery Race

Form Energy’s iron-air batteries move to commercial scale, offering a 100-hour storage solution for AI data centers and a strained U.S. power grid

27 Mar 2026

The American power grid is getting a second life from an unlikely source: rust. Form Energy has officially moved its iron-air battery technology from the lab to the factory floor. By using iron, water, and air, the company has developed a system that breathes in oxygen to discharge power and exhales it to recharge. This reversible rusting process offers a cheap, safe alternative to the lithium-ion batteries found in your phone or car.

While standard batteries usually tap out after four hours, these iron-air systems can keep the lights on for a full 100 hours. That duration is the holy grail for grid operators who need to bridge the gap during long stretches of calm winds or cloudy skies. The shift to commercial scale is happening at Form Factory 1 in Weirton, West Virginia. It is poetic justice for a town built on steel, as a former mill site now serves as the hub for this next-generation iron technology.

The business world is taking notice. In late March 2026, Form Energy announced a massive deal with Crusoe to provide storage for AI data centers. This follows a separate agreement for a Google project in Minnesota. Between these contracts, the company has a pipeline exceeding 75 gigawatt-hours. AI requires an immense, steady flow of electricity, and these batteries allow tech giants to store renewable energy for days rather than minutes.

This domestic manufacturing push arrives just as the U.S. energy sector is hitting its stride. In 2025, the country installed 18.9 gigawatts of battery storage, but most of those systems were designed for short bursts of power. Iron-air technology changes the math entirely. By providing a low-cost way to store energy for nearly a week, this tech could finally make the dream of a fully resilient, renewable grid a practical reality.