Develops fusion power plants using stellarator technology for clean energy.
Proxima Fusion is an energy technology company developing commercial fusion power plants based on quasi-isodynamic (QI) stellarators. The company’s technical approach involves leveraging advancements in magnetic confinement fusion research, including sophisticated stellarator optimization, computational design, and high-temperature superconducting magnet technology. This strategy builds directly upon the scientific achievements of the record-breaking Wendelstein 7-X stellarator experiment at the Max Planck Institute for Plasma Physics.
Founded in April 2023, Proxima Fusion emerged as the first research spin-off from the Max Planck Institute for Plasma Physics. The company's five co-founders are Francesco Sciortino, Lucio Milanese, Jorrit Lion, Jonathan Schilling, and Martin Kubie. These individuals brought expertise from their tenures at institutions like the Max Planck Institute for Plasma Physics, the Massachusetts Institute of Technology, and X Development, collectively recognizing a clear path to make fusion power grid-ready.
The company envisions its stellarator-based power plants delivering clean, safe, and abundant energy to the electrical grid. Proxima Fusion's mission is to lead Europe in establishing commercial fusion as a foundational component of its energy infrastructure, ultimately making fusion an integral part of the energy system and reducing reliance on traditional energy sources. The long-term vision is to create a new era of clean energy for a sustainable future.
| Investor | Firm Type | Partner |
|---|---|---|
| Government Office | — |
This company has completed 7 funding rounds. Current round is highlighted.
Total Raised
$1.1B
Top Valuation
-
Proxima Fusion raised $472M in a Grant round.
The round was led by Free State of Bavaria.
Proxima Fusion is a fusion energy startup that designs and builds commercial fusion power plants using quasi-isodynamic (QI) stellarator technology.[1][2] The company's mission is to deliver abundant, clean, and safe fusion energy to the grid by commercializing decades of research from the Max Planck Institute for Plasma Physics.[1]
The company serves the global energy sector with a solution to one of humanity's most pressing problems: providing scalable, carbon-free baseload power. Proxima's growth momentum is substantial—founded in 2023, it has raised €185 million in combined public and private funding as of mid-2025, including a €130 million Series A round in June 2025 plus a €15 million extension in September 2025.[4][6] The company now employs over 80 people across offices in Munich, near Zurich, and at the Culham fusion campus near Oxford.[2]
Proxima Fusion was founded in April 2023 by five scientists and engineers: Francesco Sciortino, Lucio Milanese, Jorrit Lion, Jonathan Schilling, and Martin Kubie.[4] The founding team brought exceptional pedigree—members came from the Max Planck Institute for Plasma Physics, MIT, and X Development (formerly Google-X).[4] Notably, Proxima is the first-ever research spin-out from the Max Planck Society's Institute for Plasma Physics.[4]
The company emerged directly from the success of the Wendelstein 7-X (W7-X) stellarator, the world's most advanced stellarator, which was completed in 2015 and has repeatedly broken key performance records.[1] Rather than starting from theoretical foundations, Proxima leveraged a decade of proven research and engineering breakthroughs to accelerate the path from laboratory success to commercial viability. The founding team recognized that advances in stellarator optimization, computational design, and high-temperature superconducting (HTS) magnet technology had matured enough to enable economically viable power plants.[1][5]
Technology approach: Proxima develops QI-HTS stellarators—a magnetic confinement fusion design where toroidal currents cancel out to zero, enabling stable and continuous operation.[4][8] This contrasts with tokamak designs favored by competitors and offers unique robustness features.[8]
Institutional foundation: The company is built on the achievements of W7-X, providing validated physics and engineering insights that reduce technical risk compared to startups building from first principles.[1][5]
Team composition: The founding team combines deep fusion physics expertise (Milanese holds a PhD in theoretical plasma physics from MIT; Schilling conducted doctoral research at Max Planck IPP) with world-class engineering talent (Kubie architected projects at McLaren Racing and led autonomous drone deployment at Google X).[3]
Peer-reviewed design: Proxima published its Stellaris commercial fusion power plant concept in early 2025 as a peer-reviewed, first-of-its-kind design for a commercial stellarator power plant, demonstrating scientific credibility.[2][7]
Strategic partnerships: The company maintains close collaboration with Max Planck IPP and other European research institutions including Karlsruhe Institute of Technology (KIT) and FZ Jülich, creating an integrated European fusion ecosystem.[2]
Proxima Fusion operates at the intersection of three converging trends: the global energy transition away from fossil fuels, the maturation of fusion physics after decades of research, and the emergence of deep-tech venture capital willing to fund long-duration, capital-intensive projects.
The timing is critical. While fusion has long been dismissed as perpetually "30 years away," recent breakthroughs—including the 2022 achievement of net energy gain in inertial confinement fusion and sustained high-performance operation of W7-X—have shifted fusion from speculative physics to engineering-focused commercialization.[5] Proxima's stellarator approach is gaining credibility as an alternative to the tokamak-dominated landscape, potentially diversifying the fusion technology portfolio.
Proxima is catalyzing a new European fusion ecosystem.[5] By establishing offices across multiple countries and partnering with academic institutions, the company is creating infrastructure and talent pipelines that benefit the broader European deep-tech sector. Its success could position Europe as a competitive hub for fusion innovation, countering dominance by U.S. and Chinese fusion initiatives.
Proxima Fusion is executing an ambitious but credible roadmap: completing its Stellarator Model Coil by early 2027, achieving net energy demonstration with the Alpha device by 2031, and deploying the commercial Stellaris power plant in the mid-to-late 2030s.[2] The €185 million in funding provides runway for these milestones, though fusion development remains capital-intensive and technically uncertain.
The company's influence will likely grow as it progresses toward demonstration. Success with Alpha would validate the QI stellarator approach and attract additional capital and talent to the sector. Conversely, delays or technical setbacks could reshape investor confidence in stellarator commercialization relative to competing fusion approaches.
What makes Proxima distinctive is not just its technology, but its institutional advantage: a founding team with direct access to W7-X's validated physics, combined with engineering talent from cutting-edge industries. In a field where decades of research precede commercialization, that foundation matters enormously. The next critical inflection point arrives in 2027 with the Model Coil completion—a technical milestone that will either accelerate or temper expectations for stellarator-based fusion energy.