1
Country: Germany | Funding: €607.5M
Proxima Fusion is a spinout from the Max Planck Institute for Plasma Physics that is building a quasi-isodynamic (QI) stellarator - fusion reactor that uses magnets to hold superheated gas in place so atoms can fuse and release energy. In this approach magnetic confinement toroidal currents are canceled to zero, resulting in uniquely robust characteristics. In the absence of toroidal plasma currents, current instabilities and the risk of failures that can occur in tokamaks and other stellarator concepts can be completely eliminated. The company has also developed a new heat removal technology and has already tested an island divertor at facilities at the Institute.
Proxima Fusion is a spinout from the Max Planck Institute for Plasma Physics that is building a quasi-isodynamic (QI) stellarator - fusion reactor that uses magnets to hold superheated gas in place so atoms can fuse and release energy. In this approach magnetic confinement toroidal currents are canceled to zero, resulting in uniquely robust characteristics. In the absence of toroidal plasma currents, current instabilities and the risk of failures that can occur in tokamaks and other stellarator concepts can be completely eliminated. The company has also developed a new heat removal technology and has already tested an island divertor at facilities at the Institute.
2
Country: USA | Funding: $169M
Type One Energy uses an enhanced version of a 1957 experimental Stellarator invented by US scientist Lyman Spitzer. The co-founders of Type One Energy built the world’s first optimized stellarator at the University of Wisconsin-Madison in the 1990s and conducted foundational stellarator research on it in the early 2000s. Using non-planar, high temperature superconducting magnets to optimize plasma flow, Type One Energy can surpass all fundamental technical barriers to achieving fusion energy at commercial scale. The company is building Infinity One prototype together with the 400 MWe Infinity Two fusion power plant.
Type One Energy uses an enhanced version of a 1957 experimental Stellarator invented by US scientist Lyman Spitzer. The co-founders of Type One Energy built the world’s first optimized stellarator at the University of Wisconsin-Madison in the 1990s and conducted foundational stellarator research on it in the early 2000s. Using non-planar, high temperature superconducting magnets to optimize plasma flow, Type One Energy can surpass all fundamental technical barriers to achieving fusion energy at commercial scale. The company is building Infinity One prototype together with the 400 MWe Infinity Two fusion power plant.
3
Country: USA | Funding: $140M
Thea Energy is developing pixel-inspired Helios fusion reactor that will offer a lower cost than competitors. It's a stellarator - a special type of reactor that uses magnets to shape plasma fuel into the desired shape. These magnets are small, identical superconducting magnets, allowing for mass production. The startup will use software to individually control each magnet to generate magnetic fields that can replicate the stellarator's unstable shape. This approach allows rapid optimization of the magnet design. Helios is projected to generate 390 megawatts of electricity at a cost of under $150 per megawatt-hour. Production is scheduled to start around 2030.
Thea Energy is developing pixel-inspired Helios fusion reactor that will offer a lower cost than competitors. It's a stellarator - a special type of reactor that uses magnets to shape plasma fuel into the desired shape. These magnets are small, identical superconducting magnets, allowing for mass production. The startup will use software to individually control each magnet to generate magnetic fields that can replicate the stellarator's unstable shape. This approach allows rapid optimization of the magnet design. Helios is projected to generate 390 megawatts of electricity at a cost of under $150 per megawatt-hour. Production is scheduled to start around 2030.
4
Country: France | Funding: €47M
Renaissance Fusion is a high-temperature superconductor and stellarator company. Unlike most nuclear fusion experiments that are based on tokamaks, Renaissance Fusion is working on a stellarator reactor.
Renaissance Fusion is a high-temperature superconductor and stellarator company. Unlike most nuclear fusion experiments that are based on tokamaks, Renaissance Fusion is working on a stellarator reactor.
5
Country: Canada
Stellarex is a fusion energy development firm that uses a simplified Stellarator and milestone‑driven demonstrators to validate systems integration, de‑risk scale‑up, and execute a staged technology roadmap from prototypes through demonstration devices to commercial fusion power plants. It's running two device programs - SXA (intermediate prototype) and SX0 (net‑energy demonstrator) - run in parallel from 2026 through 2032, anchored by the launch of the Centre for Fusion Energy.
Stellarex is a fusion energy development firm that uses a simplified Stellarator and milestone‑driven demonstrators to validate systems integration, de‑risk scale‑up, and execute a staged technology roadmap from prototypes through demonstration devices to commercial fusion power plants. It's running two device programs - SXA (intermediate prototype) and SX0 (net‑energy demonstrator) - run in parallel from 2026 through 2032, anchored by the launch of the Centre for Fusion Energy.
