OpenAI is in advanced talks to purchase electricity from Helion Energy, the nuclear fusion startup in which Sam Altman is the largest individual investor, according to a report by Axios published on Monday, citing a single person familiar with the situation.
Under a framework being discussed, OpenAI would receive the equivalent of 5 gigawatts of power by 2030, scaling to 50 gigawatts by 2035, with the initial guarantee covering 12.5% of Helion's production.
The scale of those figures deserves context. Helion's existing commercial commitments total 50 megawatts, agreed with Microsoft in 2023, the world's first commercial fusion power purchase agreement, plus a 500-megawatt plant being developed with steelmaker Nucor for the 2030s.
The proposed OpenAI deal would represent a step-change into gigawatt territory. Helion has said each of its reactors will generate approximately 50 megawatts of electricity, meaning the 5 gigawatt target would require roughly 100 reactors by 2030. The 50 gigawatt figure for 2035 would require an order of magnitude more.
The talks are, by Axios's account, still early in structural terms. The framework involves many conditions that have not yet been fulfilled, including selection of a site for Helion to produce power. OpenAI declined to comment.
The conflict-of-interest dimension is the other major strand of the story. Altman has led Helion's $500 million Series E round in November 2021 and has been its board chair since 2015. He holds a stake in the company, though the precise size has not been disclosed; various reports over the years have cited a figure of approximately $375 million.
According to the Axios source, Altman has now stepped down from Helion's board entirely and recused himself from the OpenAI deal discussions. This follows an identical pattern: in April 2025, Altman stepped down as board chair of Oklo, the small modular nuclear reactor startup, in order to “avoid conflict of interest” and open up opportunities for OpenAI to pursue energy deals with that company.
The governance question is not new. It was flagged as a potential issue when Microsoft, a major OpenAI investor and partner, signed its own Helion power purchase agreement in 2023. At that point, Altman sat on both sides of a commercial relationship that could benefit him personally.
Altman's OpenAI chairman Bret Taylor maintained at the time that Altman had been transparent about his investments. The board step-down ahead of the OpenAI deal talks suggests the company is handling the issue more formally this time.
Helion, based in Everett, Washington, was founded in 2013 by David Kirtley, who serves as CEO, along with John Slough, Chris Pihl, and George Votroubek. It has raised over $1 billion in total funding, with a $425 million Series F closed in January 2025 that valued the company at $5.425 billion.
Series F investors included Lightspeed Venture Partners, SoftBank Vision Fund 2, and a university endowment alongside existing backers. The company achieved a plasma temperature of 150 million degrees Celsius in February 2026, a technical milestone that exceeded its prior record of 100 million degrees first reached in 2021.
Helion's approach differs from most fusion startups: rather than using the heat from fusion reactions to drive a steam turbine, it uses magnets to convert the energy directly into electricity, a design it argues produces power more efficiently and with fewer moving parts.
The company uses deuterium and helium-3 as fuel, in a process it says produces no long-lived radioactive waste. Commonwealth Fusion Systems, backed by Google among others, is working on a competing tokamak-based approach; Google has a 200-megawatt power purchase agreement with CFS.
Whether the OpenAI talks materialise into a signed agreement will depend on a long list of conditions, not least Helion achieving the net electricity production milestone that remains, as of now, undemonstrated.