Nuclear Fusion

Commonwealth Fusion Systems

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Private

Commonwealth Fusion Systems is building commercial fusion systems around high-temperature superconducting magnet technology developed with MIT. SPARC is its fusion-energy demonstration tokamak under construction in Devens, Massachusetts, and ARC is its planned first commercial plant designed to bring hundreds of megawatts of fusion power to the grid in the early 2030s. CFS also manufactures HTS magnets as the enabling technology behind its compact, high-field tokamak approach.

Helion Energy

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Private

Helion Energy is building fusion generators aimed at producing commercial electricity from fusion. Its Polaris prototype began operating in late 2024 and in February 2026 became the first privately developed fusion machine to demonstrate measurable deuterium-tritium fusion at 150 million degrees Celsius. Helion is now advancing Orion in Malaga, Washington, where site work began in 2025 for the company's first commercial machine intended to deliver electricity from fusion to Microsoft.

TAE Technologies

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Private (proposed TMTG merger)

TAE Technologies is a private fusion company developing hydrogen-boron fusion with a beam-driven field-reversed-configuration architecture. Its 2025 'Norm' breakthrough reduced reactor complexity enough to skip the planned Copernicus step and move directly toward Da Vinci, its first prototype power plant, while TAE Power Solutions and TAE Life Sciences commercialize adjacent power-delivery and oncology technologies derived from its fusion R&D.