Helion just heated plasma to 150 million degrees Celsius, and everyone’s acting like this is the final lap before fusion power goes mainstream. The Everett-based startup announced Friday that its Polaris reactor hit three-quarters of the temperature it needs for commercial operation. Sure, that’s impressive. But let’s talk about what nobody wants to say out loud.
They’ve promised Microsoft electricity by 2028. That’s not coming from Polaris, the reactor that just hit this milestone. It’s supposed to come from Orion, a completely different 50-megawatt reactor they’re currently building. So we’re celebrating a prototype achievement while the actual commercial unit that needs to work in less than two years is still under construction.
The Race Nobody Can Really Win Yet
The fusion space has become absurdly crowded with money. Inertia Enterprises just pulled in $450 million this week. Commonwealth Fusion Systems raised $863 million last summer with Google and Nvidia writing checks. Type One Energy is chasing $250 million. Helion itself grabbed $425 million last year from Sam Altman’s group and SoftBank.
All this cash is flooding into Technology that might not produce grid power for another decade, despite what the press releases suggest. Most startups are targeting the early 2030s for actual electricity delivery. Helion is the outlier with that Microsoft contract, which makes their timeline either incredibly ambitious or incredibly risky depending on how generous you’re feeling.
What’s interesting is how different everyone’s approach actually is. Commonwealth uses a tokamak, that classic doughnut shape with massive magnets. They need plasma above 100 million degrees. Helion went with a field-reversed configuration that looks like an hourglass, and they need temperatures around 200 million degrees to hit their sweet spot.
The Helium-3 Gamble
Here’s where Helion gets weird in a way that could be brilliant or could be a massive headache. They’re planning to use deuterium-helium-3 fuel instead of the deuterium-tritium mix everyone else is banking on. The problem? Helium-3 basically doesn’t exist on Earth in useful quantities.
Their solution is to make it themselves by fusing deuterium nuclei. CEO David Kirtley says this has been “easier to do than maybe we expected,” which is the kind of cautiously optimistic language you use when something’s working but you don’t want to jinx it. They’re producing helium-3 at high efficiency and purity, apparently. Time will tell if that scales.
The reason they’re bothering with this fuel choice comes down to how they extract energy. Most fusion companies plan to harvest heat and convert it to electricity the old-fashioned way. Helion is trying something different by capturing electricity directly from the magnetic field the fusion reaction creates. Each pulse pushes against the reactor’s magnets and induces current. It’s clever. It also requires plasmas hot enough to make other fusion scientists wince.
The company won’t say if they’ve hit scientific breakeven, that magic point where you get more energy out than you put in. Kirtley dodged the question entirely, saying they “focus on the electricity piece” rather than pure scientific milestones. That’s either refreshingly practical or a diplomatic way of saying “not yet.”
What Actually Happens in a Millisecond
The mechanics of Helion’s reactor are genuinely wild. Fuel gets injected at both wide ends of that hourglass shape and turned into plasma. Magnets accelerate both plasma balls toward each other at ridiculous speeds. When they collide in the middle, they’re already at 10 to 20 million degrees. Then more magnets compress the merged ball even further, cranking it up to 150 million degrees.
All of this happens in less than a millisecond. It’s the kind of process that sounds simple when you describe it in a sentence but involves solving about a thousand engineering problems that would make most people quit and become accountants instead.
Over the past year, Helion refined circuits in the reactor to boost electricity recovery. These are the kinds of incremental improvements that don’t make headlines but actually matter for whether this whole thing can work as a Business instead of just a really expensive science experiment.
Kirtley hinted that other fusion companies might eventually want to buy helium-3 from Helion once they realize direct electricity recovery is more efficient. It’s an interesting pivot to think about becoming a fuel supplier to your competitors, but that’s probably years away if it happens at all.
The real test isn’t whether Polaris can hit 200 million degrees. It’s whether Orion can generate 50 megawatts of reliable power by 2028 while meeting whatever terms Microsoft actually put in that contract. Because hitting temperature milestones in a prototype and delivering commercial power on a deadline are entirely different problems, and only one of them keeps the lights on.
