Form Energy raises $405M for its 100-hour iron-air batteries

Form Energy just hit a funding milestone few startups reach, announcing a $405 million Series F financing round on Wednesday that brings its total funding to more than $1.2 billion.

That’s a lot of money for a novel long-duration energy storage startup. But it’s commensurate with the challenge it has set for itself — using the chemistry that causes iron to rust to build utility-scale systems capable of cost-effectively storing energy for up to 100 hours.

It’s also one of the largest funding rounds for a cleantech firm in what has been a slow year for fundraising.

Long-duration energy storage has proved to be a difficult nut for companies to crack. The class of technologies aims to soak up wind and solar power and store it for days or even weeks on end, offering a way to plug the rare but vital gaps in electricity supply that will occur as power grids shift toward 100 percent carbon-free electricity.

Though Form’s technology remains unproven at a utility scale, the company has managed to gain more commercial traction than most long-duration energy storage startups and is currently working on several commercial deployments.

The startup’s latest funding round, led by new investors T. Rowe Price and GE Vernova, features a who’s who of cleantech financiers with a penchant for trickier sectors like long-duration energy storage.

Bill Gates’ Breakthrough Energy Ventures, Prelude Ventures, MIT’s Engine Ventures, and utility-backed investment fund Energy Impact Partners participated in the round. Other investors included TPG Rise Climate, Capricorn’s Technology Impact Funds, Coatue, NGP, Temasek, GIC, Claure Group, Gigascale Capital, Blindspot Ventures, and VamosVentures.

Alongside the new investment, Form Energy also announced a memorandum of understanding with GE Vernova, General Electric’s energy spinout, ​“regarding areas of strategic collaboration to support Form Energy as it continues to ramp manufacturing operations and commercial deployments of its iron-air battery systems.”

“After seven years of dedicated R&D, product engineering, testing, and validation, and most recently trial production, our 100-hour iron-air battery system is ready for serial production and commercial deployment,” Form Energy CEO and co-founder Mateo Jaramillo said in a press release.

The startup broke ground on its first project in August, which aims to deliver 1.5 megawatts of energy for up to 100 hours for Minnesota utility Great River Energy. It is also pursuing a 15-megawatt/1,500-megawatt-hour project with utility Georgia Power, and is working on a 10-megawatt/1,000-megawatt-hour system for utility Xcel Energy, which plans to use it to store solar power to replace energy from a retiring coal plant.

Earlier this year, Form Energy won $147 million in U.S. Department of Energy funding to build its biggest project yet — one that it claims will be the largest battery in the world in megawatt-hour terms. That project in Maine is meant to be capable of injecting up to 85 megawatts of energy into the New England grid for up to 100 hours.

Form Energy’s chemistry is well suited to tap into existing iron and steel industry supply chains. Its factory in Weirton, West Virginia, at the site of what was once the state’s largest steel mill, will be able to make 500 megawatts/​50 gigawatt-hours of batteries per year when it reaches full capacity in 2028. The factory currently employs 300 people and aims to ramp up to 750 over the coming years.

The DOE has provided hundreds of millions of dollars in funding to an array of long-duration energy storage technologies other than Form’s, with the aim of achieving a 90 percent reduction in cost over this decade. The options range from well-established pumped hydropower and underground compressed-air methods to a variety of newer electrochemical, thermal, and kinetic energy storage technologies.

But private capital is necessary along with the government support — and Form Energy now has a large pile of investor funds at its disposal.

This latest infusion will go toward ​“accelerating the expansion of our multi-day battery manufacturing, creating new jobs, and upskilling a manufacturing workforce, as well as advancing the development of a more efficient and scalable process for low-cost green iron production,” Jaramillo said.