Commonwealth Fusion Systems develops commercial fusion-energy systems based on compact tokamaks and high-temperature superconducting magnets developed with MIT. Its SPARC demonstration machine is intended to achieve net fusion energy and validate technology for ARC, a planned grid-scale fusion power plant. On August 28, 2025, CFS announced an $863 million Series B2 round to complete SPARC and advance development of its first ARC plant in Virginia. CFS is an MIT spin-out that demonstrated a world-record 20 Tesla high-temperature superconducting magnet in September 2021, validating its compact tokamak approach. The SPARC device is under construction at Devens, Massachusetts, targeting first plasma in 2027, and the ARC commercial fusion power plant follows in the early 2030s. Google signed a 200 MW PPA with CFS for ARC power, and Eni signed a multi-year collaboration in 2023. CFS raised $1.8 billion in November 2021 from Temasek, Gates and Eni, according to the earlier record.
Google, NVIDIA, Mitsubishi, Mitsui