Form Energy Raises $750 Million to Expand 100-Hour Grid Battery Production

Form Energy has raised $750 million in a Series G funding round to expand production of its long-duration iron-air batteries, giving the U.S. energy storage company fresh capital as electricity demand from data centres puts new pressure on the power grid.

T. Rowe Price led the financing and will support manufacturing and deployment of Form Energy’s battery systems. The company operates a high-volume manufacturing facility in Weirton, West Virginia, where it produces batteries designed to discharge electricity continuously for up to 100 hours.

Form Energy scales its 100-hour battery technology.

FormEnergy’ss technology differs from the lithium-ion batteries that dominate today’s grid storage market. Its system relies on iron, air, and water, using the reversible oxidation of iron to store and release electrical energy. During discharge, iron reacts with oxygen and forms rust. Charging the battery reverses that reaction, converting the rust back into iron.

The approach is intended for multi-day storage, allowing electricity generated during periods of abundant supply to be used during longer stretches when generation is constrained. That capability is becoming increasingly relevant as utilities add renewable generation and large electricity users seek more reliable power supplies.

The broader U.S. storage market is also expanding. The Solar Energy Industries Association and Benchmark Mineral Intelligence reported that the country installed 9.7 gigawatt-hours of new energy storage capacity during the first quarter of 2026, up 32% from the same period a year earlier.

Data centre projects add to demand.

Form Energy has secured several large commercial agreements as technology companies and utilities seek ways to meet growing electricity demand. Google and Xcel Energy announced plans for a 300-megawatt, 30-gigawatt-hour Form Energy battery project connected with Google’s planned data centre in Pine Island, Minnesota. The system is designed to provide its rated output for 100 hours.

Crusoe also announced an agreement in March for 12 gigawatt-hours of Form Energy’s iron-air storage systems to support AI data centres, with deliveries expected to begin in 2027. Form Energy has also announced projects involving FuturEnergy Ireland and other utilities.

Those agreements have helped expand the company’s contracted portfolio. Form Energy said earlier this year that it had more than 80 gigawatt-hours of iron-air battery systems under agreement.

Demand for electricity from data centres is rising rapidly. A 2026 update from Lawrence Berkeley National Laboratory estimated that data centres could account for 11.8% of total U.S. electricity consumption by 2030 in its reference case, with scenarios ranging from 9.5% to 15.3%.

Funding supports U.S. manufacturing expansion.

The Series G round included participation from Sequoia Capital, Janus Henderson, Franklin Templeton, PEAK6 Investments, Prelude Ventures, Engine Ventures, TPG Rise Climate, Breakthrough Energy Ventures, Coatue, Energy Impact Partners, GE Vernova and other investors.

The new capital gives Form Energy additional resources to scale manufacturing as long-duration storage moves from demonstration projects toward larger commercial deployments. Its West Virginia production base also places the company within a broader push to expand domestic battery manufacturing and supply chains.

For Form Energy, the financing comes as its 100-hour technology is being selected for increasingly large projects. The combination of new manufacturing investment and a growing contracted portfolio will test whether iron-air storage can become a significant part of the U.S. grid as power demand and storage requirements increase.