OpenAI CEO Sam Altman to Leave Board of Fusion Startup Helion Energy - The Information

Sam Altman stepped down from the Helion Energy board on Monday, clearing the way for OpenAI to negotiate a power purchase agreement that would rank among the largest ever signed with a fusion company. The deal, if finalized, would give OpenAI access to 5 gigawatts of fusion power by 2030, scaling to 50 gigawatts by 2035. At Helion's stated output of roughly 50 megawatts per reactor, that translates to approximately 100 reactors for the 2030 target and around 1,000 for the 2035 goal. The sourcing on those specific figures is thin: the 5GW and 50GW deal terms were reported by Axios, citing a single person familiar with the matter. Reuters confirmed the board departure and deal scope separately, attributing the deal figures to Axios. The Information first reported Altman's exit from the Helion board.

One complication in how the deal is being described: if OpenAI's 12.5 percent share of Helion production is meant as a fixed allocation rather than a scaling target, that 5GW figure would represent only 12.5 percent of Helion's total output, implying Helion needs roughly 40 gigawatts of total capacity by 2030. At 50 megawatts per reactor, that works out to approximately 800 reactors, not 100. The gap between 100 and 800 reactors is not a rounding error — it reflects a genuine ambiguity in how the deal terms are structured. Whether 12.5 percent is a floor, a ceiling, or a starting point that scales with Helion's total capacity is not clear from the reporting.

Helion, the Everett, Washington-based fusion startup founded in 2013 by David Kirtley, John Slough, Chris Pihl, and George Votroubek, achieved a notable milestone in February when its Polaris prototype reached plasma temperatures of 150 million degrees Celsius, approaching the 200 million degrees it estimates commercial operations will require. The company has existing commercial commitments totaling 550 megawatts: a 50-megawatt power purchase agreement with Microsoft signed in 2023, plus a 500-megawatt plant planned with steelmaker Nucor for the 2030s. A single OpenAI deal at 5 gigawatts would be roughly ten times the company's current contracted output. At 50 gigawatts, it would be nearly 100 times that.

Altman has backed Helion since 2015 and led its $500 million Series E round in November 2021; various reports have cited his total investment at approximately $375 million, though the precise stake has not been disclosed. He will maintain a financial interest in Helion and recuse himself from deal negotiations on the OpenAI side. Helion CEO David Kirtley confirmed Altman's departure in a post on X, saying the decision enables Helion and OpenAI to partner on future opportunities. Helion raised a $425 million Series F in January 2025, valuing the company at $5.4 billion. Total funding raised exceeds $1 billion.

The context is the Big Tech energy scramble. Google has a 200-megawatt power purchase agreement with Commonwealth Fusion Systems, the competing fusion startup whose magnets-instead-of-steam-turbines approach mirrors Helion's. Microsoft is simultaneously a Helion customer via the 2023 PPA and OpenAI's largest compute partner. The overlapping commitments are beginning to look less like a portfolio of clean energy bets and more like a zero-sum race to lock up fusion earliest output.

There is no site selected for an OpenAI power production facility. No commercial Helion reactor has been built. The gap between a prototype hitting plasma temperatures and a grid-scale deployment is where fusion history of engineering setbacks lives. A 2030 deadline for five gigawatts leaves little margin for the physics surprises that have historically prolonged the distance between promising result and working plant.

Helion's technical approach uses direct energy conversion, capturing plasma expansion with magnets rather than boiling water for steam turbines, and claims round-trip efficiency above 95 percent. If it works at scale, the economics improve significantly. If it does not, OpenAI's bet is on a technology that has consumed more than a billion dollars and eleven years without delivering a single watt to the grid.

What is new this time is the scale. A 50-gigawatt commitment through 2035 is not a power purchase agreement in any conventional sense. It is an option on a technology that does not yet exist, at a timeline that has almost no margin for the delays that have historically come with fusion.