Private fusion developers are splitting into two camps on how to bring their reactors to market.
Some plan to build and operate their own power plants and sell electricity directly to customers. Others are positioning themselves as equipment suppliers, licensing reactor technology to utilities and industrial buyers instead.
“From the beginning, we’ve had the vision to be the power company,” said Jennifer Ganten, chief global affairs officer of Commonwealth Fusion Systems (CFS). “The first-of-a-kind is the hardest, and you can’t outsource that, so we’re going to build and operate that first plant.”
CFS is vertically integrated, running its own magnet factory beside the assembly hall for its demonstration plant outside Boston. The plant is more than 80% complete and CFS plans to turn it on next year, alongside a separate 400 megawatt (MW) plant that will connect to the grid in Chesterfield County, Virginia.
“We plan to build and operate as well,” said Andrew Proffitt, Helion's regulatory policy lead. “That is the business we are in, to sell electrons to the grid, directly to a customer, whatever that means.”
Helion’s first power plant is already under construction, with permits and licenses in place. Its first two customers are Microsoft, supplied through the grid, and Nucor Steel, supplied directly to its facility.
Matt Miles, senior vice president of external affairs at Type One Energy, has spent nearly a decade in fusion after 12 years in the nuclear fission industry. He said his company is taking the opposite approach as an original equipment manufacturer (OEM), leaving vertical integration to partners.
“Our model is OEM. We don’t plan a lot of vertical integration towards manufacturing, and we rely on companies like Commonwealth for that,” Miles said.
“We’re fusion prime, OEM within enabling technologies,” said Mark Thomas, chief executive officer of First Light Fusion. “We have our own system architecture, but it’s a very deliberate partnership play. Our technology enables machines to be simpler and cheaper, and buildable by people in this world.”
First Light’s approach centers on target amplification technology, physical devices that create extreme conditions for fusion with applications in space and defense. The company launched a fast ignition architecture called Flair last year.
Takaya Taguchi, co-founder and chief executive officer of Helical Fusion, said his company’s business model will change as it matures. For now it is focused on building its own plant, and once that technology is commercially viable it plans to license it for use elsewhere, a strategy he said reflects the company’s limited resources.
Contracts validate the market
The comments came during a panel titled “Private Developers, Bringing Fusion to Market in the US & UK” at the UK Fusion Forum 2026, hosted by the Fusion Industry Association in London on September 15. Melanie Windridge, founder and director of Fusion Energy Insights, moderated the session.
“It provides a validation that there’s a market, and that’s an important validation across a number of stakeholders,” Ganten said of CFS’s power purchase agreements (PPAs). “We’ve sold nearly all the power for that Virginia facility when it comes online, under a power purchase agreement with a price.”
She said those customer negotiations directly shaped the final design of CFS’s power plant, and that customer engagement, along with the underlying technology, separates a commercial fusion venture from a government research project.
Miles said a commitment validates the technology differently for an OEM like Type One Energy, which is not selling electricity directly.
“It validates the technology; you have people willing to offtake the product,” he said. “We talk to the Tennessee Valley Authority (TVA) weekly, actually several times a week.”
Type One Energy signed a letter of intent with the TVA last September to co-develop its first project. Miles described the first unit as a “minimum viable product.”
“We’re very focused on the economics, but we come at it from a different direction,” Thomas said. “We’ll be building a dual-use facility that can be monetized from day one, so this commercial viability piece can be accelerated if you’ve got the right technology and the right partnerships.”
First Light Fusion is targeting a gain of 1,000 for its inertial fusion target technology, which he said is the single biggest lever for cutting electricity costs in this approach. He said the company reached a significant milestone the day before the panel.
“We recently announced that we reached 150 million degrees Celsius plasma temperature and did meaningful deuterium-deuterium fusion, the first for a fusion energy company,” Proffitt said.
Helion has built seven fusion machines over roughly a decade, each more complex than the last. Its current machine, Polaris, is the seventh, using a pulsed approach called field-reversed configuration, magnetic inertial confinement and deuterium-helium-3 fuel.
“We chose the tokamak design. It was intentional,” Ganten said. “The physics largely worked out for our machine. It’s always more to do, so then it became a systems integration and engineering challenge.”
She said CFS chose a tokamak because more than 50 have already been built worldwide, giving the industry broad familiarity with the design. CFS recently completed a preconceptual design for its follow-on plant, ARC, which it expects to begin supplying power to the grid in the early 2030s.
“We are building the world’s most advanced stellarator in the Tennessee Valley,” Miles said. “Our target is to have a fusion stellarator power plant integrated at scale in the first half of the 2030s.”
The approach builds on stellarator research at the Max Planck Institute in Germany, which demonstrated a non-destructive, steady-state plasma.
Building fusion at scale
Ganten said CFS designed the company from the outset by studying how the aerospace and automotive industries develop and deploy products quickly, aiming for plants that share a common design so components can be assembled on site.
“If you wanted not 400 megawatts but a gigawatt, you can put two units next to each other and share subsystems for economies of scale,” she said. “We’re manufacturing a magnet for SPARC right now. We’ve already decommissioned the line for a toroidal field [magnet] because that’s done. We’re going to retool that factory to do the ARC magnets starting next year.”
ARC refers to “affordable, robust and compact,” while SPARC means the “smallest possible ARC.”
“To deploy at scale, you have to have a standardized product that can be built on an assembly line,” Proffitt said. “There’s no reason fusion generators can’t be a similar commodity to aerospace.”
Helion’s headquarters in Everett, Washington sits across the street from Boeing. He said the fusion economy beyond cheaper power includes the whole supply chain, from skilled workers to machine shops and manufacturing foundries.
“It’s a relatively tiny amount of investment to get inertial fusion moving in a more coherent way in the UK,” Thomas said. “It’s pretty close to oven-baked already. Inertial fusion is dual-use, so we’re talking not just about energy but about defense and security as well.”
He said most UK inertial fusion work has so far been privately funded, and that the country already has strengths in pulse power, lasers, modeling, simulation and target design that need to be brought together.
“The Infinity Fusion Consortium came together a couple of months ago to try to replicate what we were doing in the United States with the TVA,” Miles said. “We’re not making any effort to supplant the STEP (Spherical Tokamak for Energy Production) program, we’re willing to build on it.”
He said the consortium, which also includes Tokamak Energy and the engineering firm AECOM, is looking for a UK “fast follower” project, pointing to the country’s existing regulatory framework and supply chain ecosystem as an advantage.
Taguchi said Japan’s approach sits between the UK and the US models, combining a government-led project with a private-sector acceleration program.
“One is a government-led project, now called QST Demo. The other is a private companies’ acceleration program, which is quite similar to the milestone-based program in the US,” he said. QST refers to quantum science and technology.
He said the government-led track traces back to a project originally based on the International Thermonuclear Experimental Reactor (ITER) program and resembles the UK’s STEP, while the private-led track resembles the US’s milestone-based approach.
Helical Fusion already partners with Japanese manufacturing and assembly companies as part of its own plant development, he said.
Commonwealth Fusion Systems is aiming to turn on its demonstration machine next year, the first step toward a wave of commercial-scale fusion plants that developers across the industry are targeting for the early to late 2030s.