Newsletter: The wait is over for Form Energy’s secret recipe

Now we know the answer to one of the long-standing mysteries of the clean energy industry.
By Julian Spector

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One of the long-running secrets of the energy transition finally got revealed last week.

Form Energy spent the last four years chasing a technology that can store power for days on end. The goal is to close the loop on a renewable grid by cheaply storing power across seasonal gaps in wind or solar production. 

That’s a provocative mission, made more scintillating by the pedigree of the founders:

  • Mateo Jaramillo built Tesla’s energy storage business, which probably did more than any other brand to launch energy storage into public consciousness.
  • Yet-Ming Chiang developed all kinds of battery science at MIT, where co-founders and grid experts Billy Woodford and Marco Ferrara studied.
  • Ted Wiley learned the pitfalls of challenging lithium-ion’s dominance as a founder of Aquion, a potential breakthrough storage startup that didn’t win the competition.

I’ve been trying to sniff out their secret formula for years to no avail. But they let it slip to energy reporter Russell Gold in his last story for the Wall Street Journal, and now the world knows: It’s iron and air. 

As I explained in a follow-up story, Form’s battery basically inhales oxygen from the air to rust and de-rust pellets of iron in a way that makes electrons flow. I’ll save the detailed electrochemistry for a non-newsletter setting. But the important points are:

  • Iron and air are fundamentally cheaper than the materials that go into lithium-ion batteries. That’s crucial because Form is trying to pack way more storage capacity into its systems than is cost-effective with conventional batteries.
  • These are also abundant all around the world, so they are unlikely to lead to supply chain bottlenecks. Form also signed global metals company ArcelorMittal as lead investor in a new $200 million funding round.
  • Form got a boost in developing the notoriously hard air cathode by buying the intellectual property of a startup that shut down. Fluidic made zinc-air batteries, which didn’t scale up as a battery contender. But it did figure out the air cathode part over a decade of research, and now Form can use that invention.

Storage investors seeking the Next Big Thing have bet on exotic materials over the years: molten metals, flow batteries pumping bromine or vanadium solutions. Some still invest in far-out concepts like robotic cranes stacking multi-ton blocks.

But there’s been a shakeout in the advanced storage space, and many of the survivors focus on commonplace materials and off-the-shelf equipment where possible. I asked Mateo Jaramillo if he thought the iron reveal was a little anticlimactic — it’s one of the most recognizable metals, not some futuristic super-material.

But the Form CEO, who studied theology at Yale Divinity School, told me there’s beauty in simplicity.

Boring is what scales. We can’t be infatuated with exotic things for [their own sake]. We can only be concerned with and working on relevant technologies with relevant timeframes.”

I’ll file that away for a future post titled Zen and the Art of Energy Storage.”

But I should emphasize that Form is still a few years out from building its first commercial project, and ramping up manufacturing capacity will take more time. 

The biggest open question now is how Form will actually make money. 

  • Its technology doesn’t fit any mold that currently exists. 
  • Power plants generally need to operate to make money, so if a Form plant sits around most of the year waiting for weeks of prolonged cloudy weather, it could be hard to pay off the investment.

But the company says it aims to displace gas plants that run for a good chunk of the year. That suggests a more regular cycle of filling up on surplus renewable power, discharging during valuable hours, and then being available for the days without wind and solar production.

Power markets today don’t incentivize anywhere near that amount of storage. But Form has a whole team modeling the future clean energy grid so it can show potential customers how the new technology will become useful.

And it’s hard to overstate the runway that a fresh delivery of $200 million provides, on top of $120 million raised previously.

Correction: The newsletter that went out Thursday morning said that industry groups Energy Storage Association and American Clean Power Association would merge after approval by their members. In fact, only ESA’s members need to approve the merger for it to take effect. Canary Media regrets the error.

(Lead photo: AFP/​Getty Images)


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Julian Spector is senior reporter at Canary Media.