Tokamak EnergyDesign publishedwill not construct
Tokamak Energy's published fusion pilot-plant design, intended to show that a compact spherical tokamak with HTS magnets could deliver electricity to the grid. An 11-paper Focus Collection in Nuclear Fusion (August 2026) documented the pre-concept design; the company said in the same announcement that it will not construct the plant itself.
Latest update Sep 6, 2026
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The ST-E1 pre-concept design was published in Nuclear Fusion in August 2026 and validated by a US DOE expert committee. Tokamak Energy stated it will not go on to construct this plant or future pilot plants, and its September 2026 about-page roadmap no longer lists ST-E1 or the preceding ST80-HTS prototype as machines it will build. The design remains a public systems-integration reference; commercial construction would have to come from a partner programme.
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Compact high-field spherical tokamak operating at the company's Oxfordshire campus since 2018 and the machine behind its plasma records. The spherical geometry confines plasma more efficiently per unit of magnetic field than a conventional tokamak, which is what makes a smaller, cheaper power plant plausible.
The company's high-temperature superconducting magnet business, built on REBCO tape wound in-house, sold both into fusion programmes and into non-fusion markets including power distribution, propulsion, motors and generators, and analytical science. Demo4, its 44-coil demonstration system, is the technology proof point.
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Commonwealth Fusion Systems
Compact, high-field tokamak designed to demonstrate net energy from fusion. It uses high-temperature superconducting magnets to achieve reactor-class magnetic fields in a much smaller machine, with peer-reviewed projections of roughly Q ~11 and ~140 MW of fusion power.
Commonwealth Fusion Systems
CFS' first planned grid-scale commercial fusion power plant, designed to deliver about 400 MW of clean electricity using the HTS magnet and tokamak stack proven through SPARC. The project is officially named the Fall Line Fusion Power Station and is planned for a 100-acre site at the James River Industrial Center in Chesterfield County, Virginia.
Helion Energy
7th-generation fusion prototype designed to demonstrate electricity production from fusion using Helion's pulsed magneto-inertial architecture and direct electricity recapture.
Helion Energy
First commercial fusion power plant, designed to generate 50+ MWe. Located in Malaga, Chelan County, Washington, on land leased from Chelan County PUD near Rock Island Dam. Power will be marketed by Constellation Energy to Microsoft data centers.