Google Bets Big on Nuclear Fusion With MIT Spinoff Commonwealth

Workers assemble magnets at the Commonwealth Fusion Systems campus in Devens, Mass. (Cassandra Klos/Bloomberg)

Google is making a big bet on a power source that hasn’t yet been used successfully anywhere in the world: nuclear fusion.

The tech company said on Monday that it will buy power from a planned nuclear fusion plant in Virginia developed by Commonwealth Fusion Systems, using technology based on research at M.I.T. Google will also increase an existing equity investment in Commonwealth, adding to the more than $2 billion the company has already raised.

“It’s a world-changing technology, in our view,” said Michael Terrell, Google’s senior director for clean energy and carbon reduction, on a call with journalists. The size of Google’s investment wasn’t disclosed.

Every nuclear plant in the world today is powered by fission reactions, which generate energy by splitting the nucleus of an atom. Fusion, by contrast, works by combining two nuclei, similar to how the sun produces energy.

A fusion reactor would be a breakthrough that could quickly boost electricity production at a time when the world needs much more of it for artificial-intelligence data centers and electric vehicles. The International Atomic Energy Agency estimates that a fusion reactor could generate four times as much energy per kilogram of fuel as a fission one, “and nearly four million times more energy than burning oil or coal.”

Like fission reactors, fusion plants aren’t expected to release carbon dioxide, the main gas behind global warming. Alphabet, Google’s parent, has made a pledge to match its global electricity use with 24/7 carbon-free power by 2030.

Commonwealth is among the best-capitalized companies in fusion, which has gained significant momentum in the past couple of years after decades of being seen as a pie-in-the-sky technology. The companies involved in developing the technology are privately held start-ups, and there aren’t easy ways for retail investors to buy into the trend.

Tech companies, meanwhile, have begun to put money into it. In 2023, Microsoft agreed to buy 50 megawatts of power from a company called Helion by 2028, assuming Helion can get a plant working by then. Helion is also backed by Sam Altman, CEO of OpenAI.

Google had already invested in a prior Commonwealth funding round. It has put money into another fusion firm called TAE Technologies, which is also being supported by Chevron. Big fusion projects are under way in Europe and China, too.

Google says it will buy 200 megawatts of power from a plant that Commonwealth plans to build in Chesterfield County, Va. Commonwealth expects to have that plant supplying power to the grid by the early 2030s.

The knock against fusion has been that it always appears to be 20 years away from deployment. But some analysts now say fusion could happen sooner.

One reason is that a government lab in California achieved a breakthrough called “ignition” in a fusion experiment in 2022, creating more energy from a reaction than it used to start the process. No company has replicated that feat, but Commonwealth CEO Bob Mumgaard said he expects his company will do so, in 2027.

“I’m pretty optimistic” about fusion, said Chris Gadomski, the lead nuclear analyst at Bloomberg New Energy Finance, who has visited Commonwealth’s Massachusetts lab and studied the technology. “With advancements in supercomputing, 3-D printing, advanced materials and magnets, you’ve given the scientists and the engineers the tools with which to finally work on the project.”

That said, fusion still has skeptics, and many investors haven’t fully bought in. Michael Underhill, chief investment officer at the investment firm Capital Innovations, said in an interview that he has spoken with scientists about fusion technology and they estimate it will be 15 to 30 years before it is commercially viable.

Terrell, of Google, said fusion is considered a longer-term bet for the company, “but the longer term is now feeling like it’s not as far away, and we want to make sure that we’re investing in that as well.”

Write to Avi Salzman at avi.salzman@barrons.com