Helion EnergyOperational
7th-generation fusion prototype designed to demonstrate electricity production from fusion using Helion's pulsed magneto-inertial architecture and direct electricity recapture.
Latest update Sep 16, 2026
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Operating in Everett, WA, since late 2024. Achieved 150 million degrees C and first private D-T fusion in February 2026. Helion is still working to ramp repetition rate from one pulse every ~10 minutes toward 1 Hz operation and demonstrate electricity production; a separate pulsed-power testbed (Vela) already ran at 1 Hz, but that result has not been transferred to Polaris itself as of September 16, 2026.
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Announced next steps from Helion Energy that mention Polaris.
2026–2027
Push Polaris from one pulse every ~10 minutes toward sustained 1 Hz operation - the rate Helion needs to convert fusion energy into recapturable electricity in commercial operation. A separate pulsed-power testbed, Vela, already operated at 1 Hz and moved more than 11 GJ through a simulated Polaris compression magnet, but that 1 Hz result has not been demonstrated on Polaris itself as of September 16, 2026.
Late 2026
Stand up the Tiny Merge agile testbed and use its faster experimental loop to lock in final FRC formation and ring-merging choices that flow into the Orion power plant design. On August 28, 2026 Helion completed the first vacuum pump-down, reaching 1x10-6 torr in under an hour. CEO David Kirtley's subscale-systems blog still describes Tiny Merge as being integrated in parallel with Polaris. Remaining hardware is still being installed at the Everett campus. The end-of-summer 2026 online target was not met; as of September 16, 2026 Helion has not announced first plasma or a fully online experimental campaign.
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Helion said on August 28, 2026 that it completed the first vacuum pump-down on Tiny Merge, its subscale field-reversed-configuration fusion testbed at the Everett, Washington campus, reaching a target base pressure of 1x10-6 torr in under an hour. The company said the result confirms the machine can hold high vacuum before remaining hardware is installed. Tiny Merge is roughly one-eighth the size of the Polaris prototype and is meant to iterate on plasma formation and merging faster ahead of Helion's 2028 Microsoft power-delivery deadline for the Orion plant.
Fusion developer Helion Energy closed a $465 million Series G round in early June, lifting the Everett, Washington company's valuation to about $15.5 billion. The round was led by Thrive Capital, with new backers including Lux Capital, Peak XV Partners and Ford Motor executive chairman Bill Ford, and will fund Helion's first power plant, expand Washington manufacturing, and support its pledge to deliver fusion power to Microsoft by 2028. The raise follows Helion becoming the first company in the world to secure regulatory licenses for a fusion power facility and reporting measurable deuterium-tritium fusion at 150 million degrees Celsius on its Polaris prototype.
Helion Energy on June 4 closed a $465 million Series G led by Thrive Capital at a $15.5 billion post-money valuation, lifting total funding to roughly $1.5 billion as the Everett, Washington startup races to deliver fusion electricity to Microsoft from its Orion plant in Malaga by 2028. New investors include Lux Capital, Peak XV Partners, Alta Park Capital, Anti Fund, BoxGroup and Ford Motor Executive Chairman Bill Ford, joining existing backers SoftBank Vision Fund 2, Lightspeed, Mithril, Capricorn and Good Ventures; the cash will scale manufacturing and feed the Polaris prototype and forthcoming Tiny Merge testbed campaigns.
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Smaller, agile FRC fusion testbed roughly one-eighth the size of Polaris (~8 feet long) used to iterate on plasma formation and ring-merging experiments far faster than the larger machines. Helion sees Tiny Merge as a key learning loop to de-risk Orion ahead of the 2028 Microsoft delivery deadline.
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.
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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.
TAE Technologies
TAE's streamlined fusion research machine that forms field-reversed-configuration plasmas using only neutral beam injection, reducing reactor size, complexity, and cost versus Norman while preserving the path to commercial hydrogen-boron fusion.
TAE Technologies
TAE's first prototype commercial fusion power plant, designed to deliver net electrons to the grid from the company's hydrogen-boron fusion pathway and serve as the bridge to later utility-scale plants.