Form Energy raises $240 million on iron-air battery promise

A secretive start-up called Form Energy says it’s developing and scaling the production of a new type of rechargeable battery that can store electricity for 100 hours.

Form hasn’t publicly demonstrated its technology or shared proof that it works. Nonetheless, the company has lined up more than $360 million in funding, including a new $240 million round that closed Tuesday, and partners and outside experts are optimistic about its potential.

Form Energy’s core technology is based on three cheap and readily available materials: Iron, air, and water. The battery works with a process the company calls “reversible rusting,” in which the battery charges and discharges by converting iron back and forth into rust. By using these inexpensive materials, the company aims to have its batteries cost less than $20 per kilowatt-hour, which experts say is up to one-tenth the cost of the more common lithium-ion batteries in use today.

In order for carbon emissions to hit net-zero by mid-century, meaning that the globe is absorbing as much greenhouse gases as are still being emitted, solar and wind capacity will need to quadruple and investments in renewable energy will need to triple by 2030, according to comments from United Nations Secretary General António Guterres.

For that to happen, there also must be a ramp up of long duration battery storage. There has to be a way to provide electricity when the sun isn’t shining and the wind isn’t blowing. That’s the market Form Energy is attempting to serve.

One notable funder is Breakthrough Energy Ventures, which includes tech celebrities Jeff Bezos, Bill Gates, Reid Hoffman and Richard Branson as investors. In one of his blog posts, Gill Gates touted the importance of Form Energy’s work, writing that it was “creating a new class of batteries that would provide long-duration storage at a lower cost than lithium ion batteries.”

Its first utility partner, Minnesota-based Great River Energy, describes their work together as a pilot project that could be an “important contribution to grid reliability and energy affordability should they achieve commercial success,” a spokesperson says.

Until recently, the company had been operating under the radar. In October 2019, CEO Mateo Jaramillo, a former Telsa vice president, noted his own reticence to speak with the media.

“As you’ve maybe seen, there isn’t a lot of press about us. And we’ve tried to tamp down anything other than what’s necessary,” he told CNBC at the time, speaking at the Tough Tech Summit in Boston, in the backyard of the company’s headquarters in Somerville, Mass. “There’s just a fraught history with battery startups over the last 15 years. Which is why that hesitancy in general. The industry is a little weary, I would say.”

Despite the company’s early tendency to skirt the spotlight, it’s had no trouble raising funds. On Tuesday, Form Energy announced…