Modern Hydrogen — a clean energy startup with technology that at one time seemed to delight Bill Gates and attracted his investment — has now laid off most of its employees and left contractors and vendors anxious about unpaid invoices.

The Seattle-area company has not publicly offered an explanation for the downsizing or said how many workers were impacted. In a recent email to business partners, officials referenced recent funding changes and said it was undergoing a “broader restructuring effort.”

Modern Hydrogen raised $125 million since launching a decade ago. It developed a device for cracking natural gas molecules, producing hydrogen as a climate friendly fuel and a material known as solid carbon that has a variety of industrial uses, including as a key ingredient in asphalt.

Gates explored that application during a visit to Modern Hydrogen last year. The Microsoft co-founder grabbed a wheelbarrow and shovel to fill a parking lot pothole with the carbon-trapping asphalt.

The layoffs hit as the company was preparing to finish its first commercial unit for a customer in Texas and had performed two successful pilot projects with utilities in Portland, Ore., and Miami.

In January, Modern Hydrogen announced a memorandum of understanding with Puget Sound Energy, a major Seattle-area utility, to collaborate in identifying industrial customers interested in the clean hydrogen technology. That was expected to include steel and cement makers and pulp-and-paper manufacturers that use processes requiring ultra-high temperatures that could be met by hydrogen.

Given that the company had seemingly solved the new technology’s technical hurdles and was building commercial momentum, employees and business partners were surprised by the layoffs.

“A lot of folks were rooting for us,” Michael Jung, Modern Hydrogen’s former government affairs and public policy lead, told GeekWire. “I think we would have solved some key problems in the energy transition.”

On Oct. 30, Amir Moftakhar, Modern Hydrogen’s chief financial officer, sent an email to some of its subcontractors and vendors disclosing the change of course.

“We wanted to inform you that, due to recent changes in our funding situation and a significant reduction in company operations, we must terminate our engagement with you effective 10/30/2025,” stated the email, which was shared with GeekWire by one of its recipients.

“This decision is part of a broader restructuring effort which is being developed and does not reflect on your work,” Moftakhar continued. “We want to sincerely thank you for the professionalism, dedication, and quality you’ve shown throughout our collaboration and for your understanding.”

It is unclear if the company is closing entirely, what will happen with the machinery and technology, and if some component of the effort will continue in a different form.

GeekWire reached out to Modern Hydrogen CEO Tony Pan for an official comment and will update the story if he responds. We contacted a Gates’ representative for a comment as well.

One subcontractor, who asked not to be named, said that until the email went out, “things were cooking along” in their collaboration with Modern Hydrogen. Now the company is anxious about if and when it will get paid for outstanding invoices that total tens of thousands of dollars.

Modern Hydrogen got its start in 2015 at Intellectual Ventures, an innovation hub created by former Microsoft researcher Nathan Myhrvold with backing from Gates. The startup, which was originally called Modern Electron, initially focused on devices that paired with home furnaces and hot water tanks to capture the appliances’ wasted heat and turn it into electricity.

In 2023 it pivoted to focus on hydrogen and changed its name. The company’s most recent round was $25 million raised a year ago. It had approximately 80 employees at the time, according to an analysis of LinkedIn data. Modern Hydrogen co-founder and former CTO Max Mankin left the company in January.

Gates has in the past been an enthusiastic supporter of hydrogen fuel. In June 2022, he posted a Gates Notes touting the so-called “Swiss Army knife” of clean energy given its versatile applications. He was a prominent investor in the company, whose other backers included NextEra Energy, one of the world’s largest utilities; Miura; National Grid Partners; IRONGREY; Starlight Ventures; Valo Ventures and Metaplanet.

Hydrogen saw a surge of interest during the Biden administration, which created hydrogen hubs around the U.S. to bolster the technology. That support has been curtailed under the Trump administration, which canceled funding for hubs in the Pacific Northwest and California, while the remaining five hubs appear to be at risk of losing support.

And on Oct. 28, Gates posted a memo on his personal blog that dampened his earlier excitement around climate efforts.

“Although climate change will have serious consequences — particularly for people in the poorest countries — it will not lead to humanity’s demise,” Gates wrote. “People will be able to live and thrive in most places on Earth for the foreseeable future.”

Editor’s note: Information added Dec. 4 to provide detail on the hydrogen hubs.