- Proxima Fusion has secured €411 million in funding, giving the company a €2.4 billion valuation. This is the largest private fusion funding round ever in Europe.
- Both Google and RWE are taking part in this funding round. With this move, Google is now backing fusion companies in Europe as well as in the United States.
- The money will go toward developing Alpha, a demonstration project planned for a former nuclear fission site in Bavaria. This investment comes after Commonwealth Fusion Systems raised nearly $3 billion in the United States.
Proxima Fusion announced a €411 million funding round at a €2.4 billion valuation, making it Europe’s best-funded fusion startup. XTX Ventures and East X Ventures led the funding round, with RWE and Google joining as strategic investors.
This is Google’s first investment in a European fusion company. The company still continues to fund TAE Technologies, a rival fusion developer in the US, which it has backed since 2014.
Other backers included KfW Capital, SPRIND, Burda Principal Investments, and returning investors such as Plural, Balderton, and Cherry Ventures. RWE joined soon after, agreeing to work with Proxima on the stellarator plant and offering both funding and industrial support.
East X Ventures also co-led Tokamak Energy’s $125 million Series C round and now invests in both of Europe’s top tokamak and stellarator companies. XTX Ventures, which is part of Alex Gerko’s XTX Markets, has backed more than 100 companies, including Kopa AI and Lucida Medical.
After this funding round, Proxima has raised more than €650 million in total, including €95 million in public grants.
A stellarator, not a tokamak
Proxima Fusion was founded in 2023 by Francesco Sciortino, Lucio Milanese, Jorrit Lion, Martin Kubie, and Jonathan Schilling from the Max Planck Institute for Plasma Physics, MIT, and Google X. The company is based in Munich, with offices near Zurich and Oxford, and has about 200 employees.
Proxima is working on quasi-isodynamic stellarators, a type of magnetic confinement reactor. Unlike the tokamaks used by Commonwealth Fusion Systems and Tokamak Energy, stellarators avoid plasma disruptions caused by large internal currents.
Proxima’s main design, Stellaris, is the first stellarator power plant concept to be peer-reviewed. While tokamaks like CFS’s SPARC need to operate in pulses, Proxima says stellarators can run continuously, which could make them more stable.
TAE, which is also backed by Google, uses a different method: a beam-driven field-reversed configuration with hydrogen-boron fuel, rather than the deuterium-tritium cycle used by most tokamaks and stellarators. TAE and Proxima are not direct technical competitors, but they show Google’s interest in supporting different approaches to fusion. By investing in both, Google is betting on several possible breakthroughs.
Proxima has fewer competitors in Europe than TAE or CFS do in the United States. CFS has raised almost $3 billion and is working toward net energy gain with its SPARC tokamak. Helion Energy, supported by Sam Altman, raised $465 million in June 2026 at a $15.5 billion valuation and has started building a commercial plant in Washington state. Marvel Fusion in Germany, which uses lasers, has raised €385 million.
With a €2.4 billion valuation, Proxima is the only European fusion company that can financially compete with American firms, although it still has less than half the capital of CFS.
Investing in a former nuclear site
Most of this funding will go toward Alpha, a net-energy stellarator demonstration project that Proxima will develop with RWE and the Max Planck Institute at a former nuclear fission plant in Gundremmingen, Bavaria. This is also where Proxima plans to build its commercial reactor, Stellaris.
The funding round comes after Proxima received €400 million from the state of Bavaria in February 2026. The new investment exceeds the private capital required by that agreement, highlighting the success of the public-private funding model.
“Europe is racing with the United States and China to get to the first fusion power plant. Proxima’s financing demonstrates that Europe can not only invent breakthrough technologies, but also build globally competitive companies around them. Investors recognise both the urgency and the opportunity of what we’re doing and are backing us to develop a generational energy technology company,” says Sciortino.
The global nuclear energy market was worth $382.4 billion in 2024 and could reach $754.2 billion by 2030, growing at a 12% annual rate. Although commercial fusion is not yet reflected in these numbers, Proxima Fusion’s €2.4 billion valuation signals strong confidence that it will be included in the future.
Europe has shown it can fund fusion projects on a scale comparable to the largest in the United States. The main question now is whether the former nuclear site in Bavaria will be the first to supply fusion power to the grid, or if it will end up as the most expensive stellarator experiment so far.
