Commonwealth Fusion Systems

Commonwealth Fusion Systems (CFS) is the world's largest and leading commercial fusion energy company, founded in 2018 as a spin-off from MIT's Plasma Science and Fusion Center. The company's core technology centers on revolutionary high-temperature superconducting (HTS) magnets-specifically its proprietary VIPER cable, made from yttrium barium copper oxide (YBCO) tape-capable of generating magnetic fields of 20 tesla. These magnets enable compact tokamak designs that can achieve net energy fusion at a fraction of the size and cost of legacy approaches like ITER. By partnering with MIT and applying peer-reviewed plasma physics, CFS is building SPARC, the world's first commercially-relevant net-energy fusion machine, at its Devens, Massachusetts campus. As of 2025, SPARC is approximately 75% complete.

Once SPARC demonstrates net energy gain from fusion, CFS plans to build ARC, a ~400 MWe grid-scale commercial fusion power plant to be sited at the James River Industrial Center in Chesterfield County, Virginia, targeting operation in the early 2030s. ARC would be the world's first grid-connected fusion power plant-a historic milestone for clean energy. In July 2025, Google signed a landmark direct corporate power purchase agreement for 200 MW from ARC, the first-of-its-kind deal for a fusion power plant, signaling serious commercial confidence. That same year, Italian energy giant Eni signed a $1 billion deal to purchase power from ARC's first reactor.

CFS represents a pivotal node in the US energy supply chain. As an equipment manufacturer, CFS is vertically integrating the production of advanced HTS magnets and tokamak components, building domestic industrial capacity for fusion-grade superconducting technology that has broad applications beyond energy. Its Devens campus serves as a full-cycle R&D, manufacturing, and assembly hub. With over $3 billion raised and backing from leading technology investors, CFS is the best-capitalized private fusion company in the world and is catalyzing an entirely new segment of the US clean energy supply chain-one that could eventually displace baseload fossil fuel generation with carbon-free, always-on fusion electricity.