Helion Energy is building a fusion power plant. Can its technology deliver? | Scientific American
May 19, 2026<br>8 min read<br>Add Us On GoogleAdd SciAm<br>Helion Energy wants to build fusion power on a start-up timeline
This company says its pulsed plasma machine will deliver electricity to the grid by 2029. Some physicists warn that its promises are outrunning what the technology has proved
By Alex Pasternack edited by Eric Sullivan
Polaris, Helion's seventh-generation prototype, glows pink during recent testing with deuterium-tritium fuel, signaling that a thermonuclear reaction is underway.
Helion
Just east of Malaga, Wash.—a farm town in apple country—the Columbia River runs between basalt bluffs past the Rock Island Dam, which has turned water into electricity for the Pacific Northwest since 1933. Now, on a flat stretch of land nearby, a very different kind of power project is taking shape.<br>Helion Energy, one of the world’s best-funded private fusion companies, is building what it calls Orion: a machine it says will become the world’s first fusion power plant, delivering 50 megawatts of electricity to Microsoft data centers by 2029. In a field long dominated by laboratory milestones and moving timelines, Helion, backed by the likes of OpenAI CEO Sam Altman, is the first fusion company to make a commercial promise, one that provides a useful lens on the new industry: well-funded, ambitious and entangled with artificial intelligence’s huge appetite for power.<br>“The pressure’s on for Helion and everyone else,” says David Kirtley, Helion’s CEO. He has a ready reply to the old joke about fusion always being 20 years away. “I say, ‘We’re 20 years late. We need to step up and build these [plants] and deploy them at scale.’”<br>On supporting science journalism<br>If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.<br>Private money has flooded the field. Big tech companies are signing power deals with fusion firms years before any commercial machine has delivered electricity. AI is not the only reason for this rush, but it has sharpened the urgency. Data centers require staggering amounts of around-the-clock electricity; fusion start-ups are selling a path to firm, carbon-free power. “It’s a situation that’s certainly unlike any other energy technology,” says Troy Carter, director of the Fusion Energy Division at Oak Ridge National Laboratory—and, he adds, “maybe unlike other technologies.”<br>But you can’t buy your way around the laws of physics. Even as the walls at the Orion site rise, big questions swirl over the company’s bold promises—including from one of Helion’s co-founders.<br>Fusion happens in stars all the time. But doing it on Earth is harder: first, you must heat light nuclei into plasma at temperatures above 100 million degrees Celsius, then keep them hot, dense and stable long enough for sufficient reactions to occur. That’s the first challenge.<br>Fuel and materials pose more hard problems. The most practical fusion fuel—deuterium and tritium, both hydrogen isotopes—throws off fast neutrons that bombard their surroundings, degrading the very machine meant to contain the reaction. And tritium is radioactive, with a relatively quick half-life of 12 years, and barely exists in nature. Any reactor running on deuterium-tritium fuel will need to breed its own tritium supply—one of a number of burdens that, as Carter says, the industry has yet to seriously address, leaving them to hope the national labs will carry that load.<br>Helion, based in Everett, Wash., is betting on one of the more obscure fusion ideas: a linear reactor built around a plasma shape called a field-reversed configuration, or FRC. Unlike the doughnut-shaped steady-state plasma that forms inside a tokamak or the asymmetrical ribbon of plasma coursing around a stellarator, an FRC plasma, resembling a spinning smoke ring, holds itself in place, requiring fewer external magnets. An FRC reactor “has very few external magnets,” Carter says. “The magnets you need are much less complex, much lower field and less costly.” The catch is confinement: FRC plasmas are notoriously hard to stabilize as they take in more energy.<br>Trenta, Helion's sixth-generation prototype, produced plasma temperatures of 100 million degrees Celsius during testing—a record for a private fusion machine.
Helion
“The unique thing about FRCs: We call them ‘self-organized,’” says experimental physicist John Slough. “It’s like spinning a top.” But “if you try to screw around with it, you’re just going to mess it up.”<br>Slough spent decades working to keep the idea alive. By the early 2000s...