Proxima Fusion, a Munich-based energy company, is pursuing an ambitious and technically demanding approach to commercial fusion power that hinges on mastering one of the world's most complex manufacturing challenges: building intricate magnetic coils at scale and cost.
The company recently secured €400 million in funding from the state of Bavaria and is bidding for more than a billion dollars from the federal government, with a decision expected next year. At stake is whether a stellarator—a magnetically-confined fusion reactor with a far more complicated geometry than its rival design—can become economically viable.
The Technical Gamble
Proxima's Alpha stellarator is described by co-founder and CEO Francesco Sciortino as a "dumb machine" that, if successful, will operate "just like a microwave oven." The device is intended to produce more energy than it consumes, with lessons from Alpha informing the design of a more advanced fusion power plant called Stellaris.
The stellarator design uses magnets to manipulate plasma but employs a reaction container with twists and turns that make it substantially more difficult and expensive to build than a tokamak, the doughnut-shaped alternative being pursued by competitors. Sciortino argues that if the design works, the stellarator's complex geometry makes controlling the burning hot plasma easier than in tokamak designs, describing a tokamak as a "beast" while the stellarator is a "little cat."
The project builds on decades of research by Germany's Max Planck Institute for Plasma Physics and its W7-X stellarator.
Manufacturing as the Critical Constraint
Sciortino acknowledges the core risk plainly: "I lose sleep over whether Proxima will be able to build the magnets, with their intricate shapes, at a speed and cost that will make the stellarator an economic proposition." The company uses a very expensive type of steel in its magnets, requiring machining to high precision levels. Proxima describes its twisted geometry as one of the most complex magnets in the world.
A prototype magnetic coil is currently under construction and is planned to be tested next year. Once testing is complete, the company plans to build 40 more magnetic coils for Alpha. A magnet factory is in early stages of construction to support this production ramp.
Sciortino cites Germany's manufacturing infrastructure as a competitive advantage, noting there are approximately 550,000 CNC machinists in Germany compared with 350,000 in the entire United States. He emphasizes that maintaining high precision while accelerating development is crucial, noting that the W7-X took more than a decade to reach operation. "In 2028, 2029 we need to be able to make magnets at a crazy, crazy speed," he stated.
Competing Approaches in a Crowded Field
Proxima is one of 53 fusion projects tracked by the Fusion Industry Association. A major competitor is UK-based Step, which is pursuing the tokamak approach with government backing and plans to build a prototype power plant on the site of a former coal-fired power station in West Burton, Yorkshire.
Ryan Ramsey, director of Organisational Performance at Step and formerly captain of the nuclear submarine HMS Turbulent, argues that tokamaks benefit from "the advantage of a deep experimental foundation built over decades" and have "demonstrated plasma performance closer to what's required for a fusion power plant, including operation with fusion fuel." He notes that tokamaks feature "comparatively simpler magnetic geometry, with fewer and more regular coils," which has implications for manufacturability, maintainability and cost.
Ramsey frames the broader competition constructively, stating that the fusion industry is well beyond a physics experiment. "There's real momentum across fusion right now, and that should be seen as a strength rather than something to divide. This isn't a single-path race, it's a set of approaches exploring different trade-offs. The real question now is not which concept is most interesting, but which can credibly deliver a power plant."
European Manufacturing as Strategic Asset
Sciortino argues that Europe retains a significant advantage in precision manufacturing capability. "We [Europeans] missed the digital wave, didn't we? But it turns out that we still have people being trained in manufacturing," he said, noting that key suppliers exist across Europe that could position the continent at the forefront of a future fusion industry.
Fusion technology aims to replicate the reaction powering the Sun, potentially delivering abundant, cheap, and emission-free electricity. Success requires fusing hydrogen nuclei at temperatures many times hotter than the Sun's surface, with the fuel—typically a combination of the hydrogen isotopes tritium and deuterium—heated into a burning plasma that must be precisely controlled and manipulated.
Why This Matters:
Proxima's €400 million investment and billion-dollar federal funding bid represent a significant capital commitment to a single technological approach whose commercial viability remains unproven. The company's success depends entirely on solving a manufacturing problem—producing complex magnets at scale and cost—before competing designs reach commercialization. The stellarator's acknowledged complexity and expense contrast with tokamak designs that benefit from decades of experimental validation and simpler manufacturing geometry. Germany's manufacturing workforce advantage may prove decisive, but Sciortino's own acknowledgment that he "loses sleep" over cost and speed suggests substantial execution risk remains. The outcome will determine not only whether this particular fusion approach succeeds, but whether government investment in speculative energy technology yields returns comparable to market-driven alternatives.