What Commonwealth Fusion Systems does
Commonwealth Fusion Systems (CFS) is a private company founded in 2018 and based in Devens, Massachusetts. It is trying to turn nuclear fusion into a commercial source of electricity. Fusion releases energy by merging light atomic nuclei. CFS builds tokamaks, doughnut-shaped machines that use magnetic fields to confine plasma, an electrically charged gas, at more than 100 million degrees Celsius.
Its core technology is a magnet wound from high-temperature superconducting (HTS) tape, which the company says produces stronger fields and allows a more compact machine. On September 5, 2021, a team from CFS and MIT's Plasma Science and Fusion Center ramped a large HTS magnet to 20 tesla. MIT said the result helped resolve the largest open question in the plan for a net-energy fusion plant.
CFS is assembling SPARC, a demonstration tokamak in Devens that it says will reach net energy in 2027. Net energy, written Q>1, means fusion yields more energy than the process consumes. The planned commercial plant, ARC, is a 400-megawatt facility in Chesterfield County, Virginia, on a site owned by Dominion Energy. CFS says it aims to put power on the grid in the early 2030s.
Why it matters
CFS describes itself as the world's largest private fusion company. It said in July 2026 that it had raised $4 billion since its founding, about 30 percent of all capital raised by the fusion industry. It has signed power deals. Google agreed in June 2025 to purchase 200 megawatts from ARC. The Italian energy company Eni signed an agreement for more than $1 billion of ARC's power in September 2025.
CFS bills ARC as the world's first commercial fusion power plant. TechCrunch reported in July 2026 that only one fusion device, the U.S. National Ignition Facility, had reached scientific breakeven. That facility uses lasers rather than magnets. Google's announcement cautioned that success is not guaranteed.
SPARC is also behind its first schedule. MIT said in 2021 that completion was targeted for 2025. TechCrunch reported in January 2026 that CFS hoped to turn the machine on in 2027. It reported in July 2026 that CFS was targeting a launch later in 2026. In September 2026 CFS said it was still completing assembly.
Recent developments
- September 30, 2026: CFS ordered more than 10,000 kilometers of HTS tape from Fujikura for ARC plants.
- September 10, 2026: CFS said Hyundai Motor Group had invested in the $1 billion round.
- July 30, 2026: CFS announced the $1 billion raise in the same week it named former Moderna finance chief Lorence Kim chief financial officer. TechCrunch wrote that CFS might go public within two or three years. A spokesperson said the hire did not necessarily mean preparations had begun.
- June 4, 2026: CFS announced five peer-reviewed papers in the Journal of Plasma Physics setting out the physics basis for ARC.
- April 28, 2026: CFS applied to connect ARC to the PJM Interconnection grid and said it was the first fusion developer to apply to a major grid.
- April 2, 2026: CFS agreed to build magnets for Realta Fusion, another fusion developer, in a partnership the companies said could reach a multibillion-dollar value.
What to watch
- When SPARC first operates, and whether it reaches Q>1 in 2027.
- ARC's grid connection, which CFS says can take four to six years from the start of studies to generating electricity.
- ARC's financing. Chief executive Bob Mumgaard said in August 2025 that the plant would likely cost several billion dollars.
- Whether CFS moves toward a public listing.
Commonwealth Fusion Systems timeline
CFS orders more than 10,000 kilometers of high-temperature superconducting tape from Fujikura for future ARC power plants.
Source: Commonwealth Fusion Systems
CFS announces a $1 billion equity raise, bringing total capital raised to $4 billion by its own count.
Source: Commonwealth Fusion Systems
CFS applies to PJM Interconnection to connect the 400-megawatt ARC plant, which it says is the first such request by a fusion developer.
Source: Commonwealth Fusion Systems
TechCrunch reports the first of SPARC's 18 magnets is installed; CFS announces a digital twin project with Siemens and Nvidia.
Source: TechCrunch
Italian energy company Eni agrees to buy more than $1 billion of electricity from the planned ARC plant.
Source: TechCrunch
Google announces an agreement to buy 200 megawatts from ARC and a second investment in CFS.
Source: Google
CFS selects a Dominion Energy site in Chesterfield County, Virginia, for ARC, its first commercial fusion power plant.
Source: Commonwealth Fusion Systems
A CFS and MIT team ramps a large high-temperature superconducting magnet to a field strength of 20 tesla.
Source: MIT News
Sources
- Commonwealth Fusion Systems Raises Another $1 Billion, Bringing Total Capital Raised to $4 Billion, Commonwealth Fusion Systems
- SPARC: Proving commercial fusion energy is possible, Commonwealth Fusion Systems
- Commonwealth Fusion Systems Places Largest Single Purchase Order of HTS Tape with Fujikura to Accelerate Development of ARC Power Plants, Commonwealth Fusion Systems
- Commonwealth Fusion Systems Announces Equity Investment by Hyundai Motor Group, Commonwealth Fusion Systems
- Commonwealth Fusion Systems Becomes First Fusion Company to Apply to PJM Interconnection, the Largest U.S. Wholesale Electricity Market, Commonwealth Fusion Systems
- Commonwealth Fusion Systems Builds on Learnings From SPARC to Publish Five Peer-Reviewed Papers Validating the Physics of the ARC Fusion Power Plant, Commonwealth Fusion Systems
- Realta Fusion and Commonwealth Fusion Systems Form Strategic Partnership to Commercialize Magnetic Mirror Fusion Energy, Commonwealth Fusion Systems
- Commonwealth Fusion Systems to Build World's First Commercial Fusion Power Plant in Virginia, Commonwealth Fusion Systems
- MIT-designed project achieves major advance toward fusion energy, MIT News
- Our latest bet on a fusion-powered future, Google
- Fusion power darling Commonwealth Fusion Systems raises another $1B, TechCrunch
- When will fusion power startup Commonwealth Fusion Systems go public?, TechCrunch
- Commonwealth Fusion Systems installs reactor magnet, lands deal with Nvidia, TechCrunch
- Commonwealth Fusion Systems books a $1B+ power deal for its future fusion reactor, TechCrunch
- Nvidia, Google, and Bill Gates help Commonwealth Fusion Systems raise $863M, TechCrunch
- Bill Gates-backed Commonwealth Fusion Systems hits key reactor construction milestone, TechCrunch
