Helion announced a power purchase agreement with Microsoft to supply electricity from its first fusion power plant, targeting an operational date of 2028. The agreement stipulates that the facility must achieve an output of at least 50 MWe after a one-year ramp-up period. This represents the first commercial PPA for a private fusion company and signals a significant step toward market entry, contingent on Helion solving outstanding physics and engineering challenges. The deal provides a concrete commercial target for the company, which is backed by OpenAI CEO Sam Altman, who also serves as Helion’s chairman. Source: MIT Technology Review

The company's approach deviates from mainstream tokamak and stellarator designs, employing a pulsed magneto-inertial fusion device that collides two field-reversed configuration (FRC) plasma rings. After collision, the combined plasma is compressed by magnetic fields to fusion conditions. Helion utilizes a deuterium-helium-3 (D-He3) fuel cycle, which produces fewer high-energy neutrons than D-T reactions, simplifying shielding and material requirements. A key aspect of its design is a direct energy conversion system that recaptures energy from the expanding plasma to generate electricity without a steam turbine, a departure from traditional thermal cycles. Source: MIT Technology Review

After collision, the combined plasma is compressed by magnetic fields to fusion conditions.

The 2028 timeline is considered highly ambitious by external experts, as Helion has not yet demonstrated net energy gain. Its sixth prototype, Trenta, achieved ion temperatures of 100 million degrees Celsius (approximately 9 keV), but the D-He3 fuel cycle requires significantly higher temperatures than D-T fusion to reach ignition. The company's seventh-generation machine, Polaris, is currently under construction and is designed to be the first device to demonstrate net electricity production. The scarcity of helium-3 is another challenge; Helion plans to breed its own He-3 fuel from D-D side reactions within its device, a process that must be proven efficient at scale. Source: MIT Technology Review

The agreement with Microsoft serves as a powerful validation tool for Helion's commercialization strategy and its ability to attract capital in the competitive private fusion sector. According to Helion CEO David Kirtley, the PPA provides a clear, market-driven objective that focuses the company's engineering and scientific efforts. While the financial terms were not disclosed, such agreements are critical for securing the project financing required for constructing a first-of-a-kind power plant. The deal shifts the conversation from purely scientific milestones, such as achieving a specific Q_plasma value, to tangible commercial deliverables like grid-connected MWe. Source: MIT Technology Review

Successful execution now depends on the performance of the Polaris prototype. Demonstrating net electricity generation will be the critical prerequisite for proceeding with the commercial plant intended to serve Microsoft. Observers will be watching for peer-reviewed data from Polaris that substantiates Helion's claims regarding plasma confinement, heating efficiency, and direct energy conversion performance. Meeting the 2028 deadline requires not only a scientific success but also navigating the regulatory, supply chain, and construction logistics for a novel power source on an accelerated schedule. Source: MIT Technology Review