Form Energy receives $30M CEC grant for its 100-hour iron-air battery system

Form Energy receives $30M CEC grant for its 100-hour iron-air battery system
(The CEC approved funding to build a long-duration energy storage project today similar to the one shown above. Source: Form Energy.)

The California Energy Commission (CEC) has approved a $30 million grant to Form Energy to build a long-duration energy storage project that will continuously discharge to the grid for 100 hours.

The 5 MW / 500 MWh iron-air battery storage is the largest long-duration energy storage project to be built in California and the first in the state to use the lower-cost technology, the CEC said. It will be built at a Pacific Gas and Electric Company substation in Mendocino County and provide power to area residents. It is expected to begin operation by the end of 2025 to help support grid reliability and demonstrate solutions needed to meet the state’s climate and clean energy goals.

Iron-air battery technology uses the principle of reversible rusting. The battery cells contain iron and air electrodes and are filled with a water-based, nonflammable electrolyte solution. While discharging, the battery absorbs oxygen from the air and converts iron metal to rust. While charging, the application of an electrical current converts the rust back to iron and the battery emits oxygen. The technology has lower costs compared to lithium-ion battery production.

“A multiday battery system is transformational for California’s energy mix,” CEC Chair David Hochschild said. “This project will enhance our ability to harness excess renewables during nonpeak hours for use during peak demand, especially as we work toward a goal of 100% clean electricity.”

Form Energy co-founder and CEO Mateo Jaramillo appeared on the Factor This! podcast earlier this year, where he discussed the company’s history and its recent efforts to commercialize its 100-hour battery.


Episode 54 of the Factor This! podcast features Form Energy co-founder and CEO Mateo Jaramillo, a former Tesla executive pushing for deep decarbonization on the grid. Subscribe wherever you get your podcasts.


At the beginning of 2023, Xcel Energy entered into an agreement with Form Energy to deploy its iron-air battery systems at two of the utility’s retiring coal plants. Xcel will deploy a 10 MW / 1,000 MWh multi-day storage system at the Sherburne County Generating Station in Becker, Minnesota. Xcel Energy–Colorado will deploy a 10 MW / 1,000 MWh multi-day storage system at the Comanche Generating Station in Pueblo, Colorado. Both projects are expected to come online as early as 2025.

In May, Form Energy started construction on its first iron-air battery manufacturing facility in Weirton, West Virginia. When fully operational in mid-to-late 2024, Form Factory 1 is expected to have an annual production capacity of 500 MW of iron-air batteries.

In June, Form Energy announced it is moving ahead under an agreement with Georgia Power to deploy a 15 MW/1500 MWh iron-air battery system in Georgia. The multi-day battery system could come online as early as 2026. In its IRP, the utility said it planned to evaluate opportunities in the 5-15 MW range to deploy this technology and it would return to Georgia regulators for project approval once it identified an optimal application.

Form Energy received the largest portion of funding- $12 million out of the $15 million total- from the state of New York in its August awards for long-duration energy storage projects. The company plans to develop, design, and construct a 10 MW/1,000 MWh iron-air battery system with a project location still to be determined.

As of August, California had 6,600 MW of battery storage in use throughout the state operating at the current industry standard of 4 to 6 hours of discharge. By year-end, the number is projected to increase to 8,600 MW, the CEC said. The state estimates more than 48 GW of battery storage and 4 GW of long-duration storage will be needed to meet the goal of 100% clean electricity by 2045.

In September, Dominion Energy Virginia proposed a pilot project to test two alternatives to lithium-ion batteries, one being Form Energy’s. In the same month, the DOE announced it would award up to $70 million to support two of Xcel Energy’s long-duration battery storage projects, both of which will utilize Form Energy’s iron-air battery technology and have a capacity of 10 MW/1,000 MWh.

The grant is one of three approved under the CEC’s Long-Duration Energy Storage program, which invests in demonstrating non-lithium-ion technologies across the state to create a diverse portfolio of energy storage technologies. Other awards approved under the Long-Duration Energy Storage Program include $31 million for a 60 MW renewable backup power microgrid in San Diego County and $32 million for a 20 MW microgrid project in Tehama County.