Helion Energy is developing the Polaris field-reversed configuration fusion reactor in Everett, Washington. In 2023, Microsoft signed a PPA to purchase 50 MW of Helion fusion power by 2028 — with Helion paying Microsoft $1/MWh for every month missed after 2028. Helion raised $425 million in January 2025 to scale commercialisation, bringing total funding to over $2.2 billion. CEO David Kirtley targets commercial fusion by 2028. Sam Altman (OpenAI CEO) personally invested $375 million and serves as Helion's Chairman.
Sam Altman ($375M), Peter Thiel, OpenAI, Facebook co-founders, YC Continuity