What is nuclear fusion - and can it power WA's data centers?
The world's largest tech companies have a problem: Their data centers for artificial intelligence require a lot of energy, which is in short supply.
So these companies are on the hunt for new sources of electricity, specifically clean energy to meet their own sustainability goals and local mandates. One Everett-based startup, Helion, is aiming at a nuclear solution: not traditional nuclear fission power, but fusion, the power of the stars.
This experimental energy source could arrive in Washington state soon, at least according to Microsoft and Helion. The two companies struck a deal to bring fusion power to Microsoft's data centers by 2028.
Helion broke ground on its Chelan County facility last summer, in hopes it can become the world's first commercial fusion power plant.
Helion has raised about $1 billion in investments as of last year, including from some of the biggest names in Silicon Valley, like OpenAI CEO Sam Altman, PayPal and Palantir co-founder Peter Thiel, and Facebook co-founder Dustin Moskovitz.
Nuclear experts say fusion power - which is clean and can run around the clock (unlike wind and solar) - could help solve the world's energy and climate crises, someday. But they're also generally skeptical of Microsoft and Helion's timeline, which is the most aggressive of any effort to harness fusion power.
So what is fusion power, and can it help solve our energy crisis?
What is fusion?
Fusion is the process of combining atoms, usually hydrogen, into heavier elements like helium. In that process, some of the mass from the original particles gets converted into huge amounts of energy.
For atoms to fuse, they need to be really hot - around 100 million degrees Celsius - and they need to be under high pressure or density for a period of time. While that happens naturally on the sun, there are two main ways to produce these conditions in a lab. Some labs blast atoms using lasers until they're hot enough to fuse. Others, like Helion, use electromagnets to essentially squeeze atoms at extremely high temperatures so they fuse.
How do you get electricity from fusion?
Most designs aim to capture electricity from fusion using steam turbines, taking heat from the reactions to produce the steam.
Helion's approach is different. The startup aims to capture electricity directly from fusion reactions through electromagnets. As the atoms fuse, the plasmas expand, pushing back against the magnetic field of the electromagnets surrounding Helion's device, inducing a current on the machine's electromagnetic coils.
CEO David Kirtley says direct electrical capture is "orders of magnitude" more efficient than steam turbines, which allows his company's fusion reactors to be much smaller and cheaper to manufacture.
Is fusion safe?
Fusion is generally considered much safer than fission reactors - which are the nuclear power plants that exist today - but it's not completely risk-free.
There's no risk of a chain reaction or "nuclear meltdown" like there can be with fission reactors. Whereas fission creates waste that stays radioactive for thousands of years and must be properly stored, any radioactivity from fusion is typically expected to decay in years or decades.
Helion's approach produces even less radiation than conventional fusion designs. Most of that radiation is absorbed by the reactor's own components, and the company plans to house the device in a room with thick concrete shielding.
Why is there so much excitement around fusion now?
Artificial intelligence companies are facing public backlash for how much electricity their data centers use, and some are driving large amounts of funding into fusion as a solution.
At the same time, technology has advanced on many key components of fusion reactors that make the engineering easier.
"Smart people 50 years ago thought up how to do this, but some of the technology that was necessary for it to be successful didn't exist," said Paul Wilson, chair of the University of Wisconsin-Madison‘s Department of Nuclear Engineering & Engineering Physics.
Wilson and other experts say high-temperature superconducting magnets and computing parts like semiconductors and fiber optics have recently become strong enough and fast enough to control fusion reactions much more easily than in the past.
Where does fusion stand?
Fusion reactions have been generated many times before, including by Helion. But fusion facilities currently consume more electricity than they produce.
Nuclear experts say even once fusion systems can produce more electricity than they consume, it could take some time before they're able to generate power at a cost that's comparable to other energy sources.
Commonwealth Fusion Systems, the most well-funded fusion company in the U.S., is also racing to build the world's first fusion power plant, and says its facility in Virginia is targeting net-positive electricity by the early 2030s, half of which it has agreed to sell to Google. Among major fusion companies, Helion has the most aggressive timeline to deliver power commercially.
Will Helion meet its 2028 deadline with Microsoft?
It's hard to tell, experts say, but they're skeptical because Helion doesn't publish its results in scientific papers the same way its competitors do. Commonwealth has shown modeling in peer-reviewed papers how its facility could get to the net-positive energy threshold, while Helion has published limited comparable data.
Kirtley says his company is more focused on solving the engineering problems in front of it and is safeguarding their technology from competitors.
Helion recently announced its latest prototype reached 150 million degrees Celsius, above the threshold to achieve fusion but short of the 250-300 million degrees the company says it needs to hit consistently for commercial operations.
Helion also has to build a 100,000 square foot building to contain its machine and connect its power plant to the electrical grid, all within two years.
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This story was originally published April 26, 2026 at 6:54 AM.