PomegraType One Energy raised $200M in a Series B co-led by Breakthrough Energy Ventures and Clutterbuck Capital, to build a Tennessee stellarator prototype before a 400 MWe plant.
Key Takeaways
- Type One closed a $200M Series B on Oct 6, 2026, co-led by Breakthrough Energy Ventures and Clutterbuck Capital.
- The round came in below the $250M target set in January, and the valuation was not disclosed.
- Groundbreaking on the Infinity One prototype is now planned for the first half of 2027.
Lead
Type One Energy, the Knoxville, Tennessee stellarator developer, announced on October 6, 2026 that it had completed a $200 million Series B financing. Breakthrough Energy Ventures and Clutterbuck Capital co-led the round. Lowercarbon Capital, Siemens Energy Ventures, SiteGround Capital and other new investors also participated.
The company did not disclose a valuation. Total funding now exceeds $400 million, according to the company's announcement.
What Is Type One Energy Building?
Type One is developing stellarator fusion power plants, a magnetic confinement design that twists the plasma-holding field with externally shaped coils rather than driving a large current through the plasma. The company was founded in February 2019 by five fusion scientists from the University of Wisconsin-Madison. Christofer Mowry is CEO.
Its plan, called Project Infinity, has two stages. Infinity One is an engineering prototype, described as roughly 30% scale, at the Tennessee Valley Authority's Bull Run site in Clinton, Tennessee. It will not sell electricity. Infinity Two is a planned 400 MWe plant at the same site, designed to produce about 800 MW of fusion power, with startup targeted for 2034.
Type One sells to utilities as an equipment supplier rather than operating plants itself. Commonwealth Fusion Systems has licensed its high-temperature superconducting magnet technology to the company, and AECOM is handling preliminary engineering for Infinity Two.
How Does This Round Compare With What Was Planned?
The round is smaller than the company signaled nine months earlier. In January 2026, Type One disclosed an $87 million convertible note and said it was pursuing a $250 million Series B at a $900 million pre-money valuation. The closed round is $50 million short of that figure.
The company has not said whether the $900 million valuation held. The convertible note converts into the new round, so some of the $200 million may represent capital already raised rather than fresh money. Neither the earlier note terms nor the conversion split has been disclosed. Read plainly, the round shows investor appetite for fusion hardware that remains real but is being priced against construction milestones.
Breakthrough Energy Ventures was already an investor, so its co-lead role signals continuity rather than a new vote of confidence. Siemens Energy Ventures is the more informative addition, since Siemens Energy is under discussion as a potential manufacturing partner.
Is $200M Enough to Build the Plant?
No, and the company says so. Mowry has said the Series B gets Type One roughly halfway toward financing the 400 MW plant, which leaves around $200 million to find under that framing. Infinity One alone carries an estimated cost of about $300 million.
Timelines have also moved. Groundbreaking on Infinity One slipped from the end of 2026 to the first half of 2027, with completion targeted for 2029. Conventional island construction for Infinity Two could begin in 2028, and the fusion island in 2030.
TVA's final decision on Infinity Two depends on Infinity One performing and on required approvals. TVA issued a letter of intent for construction in September 2025. The Tennessee regulator has granted an initial operating license for the Bull Run site, a regulatory step the company cites as evidence of progress.
What Does the Prototype Need to Prove?
Infinity One has a narrow job: showing that the design works as modeled. Mowry has described the goal as learning that the design "works as advertised." The prototype is not meant to demonstrate net energy gain or commercial output.
That is a lower bar than some fusion rivals set, and a skeptic would note that it defers the hardest questions. Stellarator coils are geometrically complex and costly to manufacture to tolerance. Tritium handling, materials durability and plant availability remain unproven at power-plant scale for every fusion developer, not only this one.
Type One's counter is its FusionDirect program, which favors established industrial materials and partners over novel supply chains. If the approach holds, it lowers cost and schedule risk. If it fails, the failure will show up in 2029, not in the next funding announcement.
What Comes Next for Fusion Financing?
Type One will need a further round or project-level financing before Infinity Two moves into heavy construction. The most plausible sources are utility and industrial partners, government programs and additional strategic investors in the Siemens mold. The UK Infinity Fusion Consortium, which includes Tokamak Energy, AECOM, Sheffield Forgemasters and Barclays, adds a second channel outside the US.
The next checkpoints are concrete: groundbreaking in the first half of 2027, the start of Infinity Two conventional construction as early as 2028, and Infinity One's completion in 2029.
Outlook
Type One has money to start the Infinity One prototype but not to finish the commercial plant, and the round closed below its January target. Investors are funding a staged, milestone-driven path rather than a bet on a single breakthrough. The 2029 prototype results will determine whether TVA proceeds with the 2034 plant and whether the second half of the capital stack arrives.