Sam Altman-Backed Fusion Startup Raises $465 Million To Build Nuclear Plant For Microsoft
https://www.nucnet.org/news/sam-altman-backed-fusion-startup-raises-usd465-million-to-build-nuclear-plant-for-microsoft-6-1-2026Sam Altman-Backed Fusion Startup Raises $465 Million To Build Nuclear Plant For MicrosoftHelion, the US fusion startup backed by Open AI founder Sam Altman, announced that it had raised $465m (€404m) in a new funding round that values the company at $15.5bn.
The cash infusion was announced as Helion is racing to complete Orion, its first power plant.
The startup has set an aggressive timeline to deploy fusion power to the grid, as early as 2028 if it can deliver on the terms of a deal to deliver power to Microsoft data centres.
Last year Helion began work on its first fusion power plant in Chelan County in Washington.
In 2023 Microsoft signed with Helion what it said was the world’s first power purchase agreement (PPA) for nuclear fusion, with the company expected to offtake up to 50 MW of capacity following a one-year ramp-up period.
The new round, a Series G, was led by Thrive Capital with a long list of participants, including new investors Alta Park Capital, Anti Fund, BoxGroup, Lux Capital, Peak XV Partners, and Bill Ford, along with existing investors, which include Capricorn Technology Impact Funds, Lightspeed Venture Partners, Mithril Capital, Dustin Moskovitz through Good Ventures Foundation, SoftBank Vision Fund 2, and a university endowment fund.
Helion’s approach to fusion power differs from many of its peers. Some use magnets to contain the superheated plasma required for fusion conditions, while others use lasers to compress fusion fuel until it reacts. In both cases, the majority of startups plan to use steam turbines to transform the intense heat into electricity.
But Helion, which uses magnets to compress the fuel, intends to harvest electricity straight from the magnets themselves. When fusion occurs in the plasma inside the reactor, it expands, pushing against the magnetic fields. That force can be drawn off the magnets as electricity, similar to how an electric vehicle can reverse its motors to provide braking force and recharge the battery.