How a secret climate star turns ‘stone soup’ into climate progress

Senior Science and Economics Correspondent
Three men stand in front of a sheer rock face.
Benjamin Mowbray, Yet-Ming Chiang and Camden Hunt (L to R) collecting rock samples from a decommissioned mine in New Mexico earlier this year. Photo courtesy of Benjamin Mowbray.

To understand what it’s like to work with and for professor and serial entrepreneur Yet-Ming Chiang, I am going to have to learn the story of stone soup.

It’s an old Eastern European tale, said Leah Ellis, the CEO of startup Sublime Systems, who worked in Chiang’s lab and went on to start the company with him.

A hungry beggar comes to a town and announces to the villagers that he can make soup out of a rock. The villagers protest, and the beggar, who is charismatic and charming, says he will prove it to them. They give him a pot of water and some fuel. And he stirs the rock in a pot of water, all the while cracking jokes and engaging with the townspeople. A villager asks why it is taking so long. And the beggar says the soup would come faster if someone gave him an onion and a carrot.

“Eventually everybody had a soup. And he did, in fact, make soup out of a stone, but not in the way that he said it in the beginning,” Ellis told me.

The prevailing interpretation of this story is that the beggar’s charisma brings out the best in the villagers and inspires them to collaborate.

This is Chiang’s superpower, Ellis said. “He’s the person saying ‘What if?’ and he’s setting the vision of the soup. And he’s really the architect of the soup,” Ellis said.

Chiang is a professor of materials sciences and engineering at Massachusetts Institute of Technology, where he started his studies as an undergraduate in 1976, became an assistant professor in 1984 and finished earning his doctorate in 1985.

A man smiles in a scientific laboratory/office, old photograph clearly circa the 1980s.

Chiang as a graduate student at MIT in Cambridge, Massachusetts in 1981. Photo courtesy of Yet-Ming Chiang.

In the decades since, he’s also learned to become a serial cleantech entrepreneur.

Chiang himself was somewhere between “ambivalent” and “reluctant” in having his career spotlighted. His capacity to be part of so many projects is a direct function of finding the right people to work with, Chiang said.

“Being at MIT he sees the crème de la crème and he has a really good eye for talent. And he has a spidey sense about people. And that is Yet’s magic: finding the things that draw people together and getting the right people around that idea,” Ellis said.

Cipher is profiling experts flying under the radar while doing big things on climate tech. This is part two of our two-part series on Chiang. Part one focused on his entrepreneurial journey. Email us your ideas for future profiles: [email protected].
Two people (a man and a woman) pose with heavy duty lab equipment. Both are smiling.

Yet-Ming Chiang and Leah Ellis, the co-founders of Sublime Systems, in Somerville, Massachusetts, in November 2023. Photo courtesy of Bob O’Connor.

Katie Rae, CEO of The Engine Ventures, a venture fund that spun out of MIT, has watched Chiang grow his entrepreneurial prowess over the years. (She’s also invested in Form and Sublime and sits on both boards.) For a professor to commercialize research from their lab — and particularly to do so repeatedly — starts with strategically picking Ph.D. and post-doctoral researchers who are thinking about scaling their scientific ideas, she said.

“You start to get people in your lab that are interested in following you as an entrepreneur” and then the lab bench-to-business flywheel “starts to really accelerate,” Rae told me. “And I think Yet is one of those very special professors who’s been able to repeat that multiple times now.”

Identifying which ideas from his research lab ought to be commercialized is another big part of the stone soup magic. Looking at a list of eight companies he has helped launch with two more in process, Chiang said he has probably worked on 10 times as many projects over 40 years of research. Not every project is a business opportunity.

There are table stakes for Chiang to think about dedicating his time to take a project from the lab to commercial scale: “It will first have to be something that is scientifically or technically really differentiated, a new way of doing something,” he told me.

“There is a bit of ego there,” Chiang said. “I wouldn’t want that company to be the fifth company to try something, the third company to try something, even the second company to try something. I want to be the first company to try something.”

A group of five people sits on stools and on a table and stand, looking at the camera and smiling. They seem to be in some kind of laboratory room.

Leadership of Form Energy in Cambridge, Massachusetts, in February 2018. Mateo Jaramillo, the CEO of Form Energy, is all the way on the left and Chiang is sitting on the table in the front. Photo courtesy of Doug Levy at The Engine.

Also, Chiang must feel his time and expertise are critical to the project’s success. Even in the battery space, where Chiang has been active for years, there are technologies other people can do better, he said.

Then, scale. “Being new and novel is definitely not enough,” Chiang said. If he’s going to work on a new company, “it has to have the potential for really big impact.”

Determining whether an innovation will scale is a combination of economics and simplicity, said Chiang.

“Probably the most important factor for scalability is that after your best clear-eyed analysis, the economics are easily understood, and compelling,” Chiang said. The economics may not pencil immediately, but they “certainly” should as the company reaches scale, “and ideally without any subsidies.”

Key to getting the economics to work is having relatively inexpensive and readily available ingredients — a core tenet of both of his buzziest climate companies, energy storage company Form Energy and green cement company Sublime Systems. “Form’s iron-air batteries and Sublime’s decarbonized cement from calcium silicate rocks are examples where the resource is essentially unlimited compared to the target scale,” Chiang told me.

Chiang also looks for a relatively simple design. If the technology depends on numerous other innovations, that’s concerning.

If he’s in, though, he’s all in.

For example, one of the three startups Chiang launched last year involves extracting lithium from hard rock resources. As part of the research, the team needed one specific type of rock that exists in only a couple mines in the United States. Camden Hunt, a program manager for the Center for the Electrification and Decarbonization of Industry at MIT, of which Chiang is a co-director, is working with Chiang on this project and identified an abandoned mine in New Mexico where they could get samples of the rock.

When Hunt knew he was going to be in Utah for a conference recently, he reached out to the caretakers of the mine and asked if he could collect some samples. The answer was yes, but they could only collect a maximum of five pounds per person. Ideally, they were hoping to collect 15 to 20 pounds of rock for research. Hunt roped in another post doctorate researcher in Chiang’s lab, Benjamin Mowbray.

Chiang also volunteered.

“I just thought that that was funny because never in my life would I think that a professor would be willing to hop on a plane after a conference, fly to a different state, get in a car, drive to an old abandoned pegmatite mine and then crawl around on a rock pile picking out this one specific type of rock,” Hunt said. “I should also mention, he seemed to have more fun I think than me and the post doc.”

They got the rocks, and Chiang brought them back with him to Boston on a plane.

“He had a suitcase full of rocks,” Hunt said.

A man excitedly collects rock in front of a sheer rock face.

Chiang collecting rocks in New Mexico in April 2024. Photo courtesy of Benjamin Mowbray.

Editor’s note: Form Energy’s investors include Breakthrough Energy Ventures, a program of Breakthrough Energy, which also supports Cipher.

An earlier version of this story incorrectly implied Sublime Systems is the only company working on electrochemical cement right now. There is at least one other company working on electrochemical cement.