The ‘Dumb Machine’ Promising a Clean Energy Breakthrough

Francesco Sciortino, co-founder and CEO of Proxima Fusion, recalls that some doubted the viability of the site where their project now stands. “A few people said that the place where Proxima is today was impossible,” he shares. This sentiment is familiar to many in the global fusion community, where scientists strive to replicate the Sun’s energy-producing process on Earth. If successful, their efforts could unlock a future of limitless, affordable, and emissions-free power. Yet, the path to achieving this remains filled with complex hurdles, and a fully functional power station is still a distant goal.

How Fusion Works

Fusion involves combining hydrogen nuclei to release energy. On the Sun, gravity sustains this reaction, but on Earth, extreme temperatures—often surpassing those of the star itself—are required. The fuel, typically a mix of tritium and deuterium, is heated into a scorching plasma. This plasma must then be stabilized and guided to trigger fusion, a task that demands precise engineering.

Choosing the Stellarator Path

Proxima Fusion is pursuing a stellarator design, which is seen as more challenging than the tokamak method. While tokamaks use doughnut-shaped chambers and strong magnets to hold plasma, stellarators have a more intricate, twisted geometry. This complexity makes them harder and costlier to construct, but proponents argue it offers greater control over the plasma. “A stellarator is a thing that is objectively very difficult to design, objectively very difficult to build,” says Sciortino. “But if you do it, it is a dumb machine—just like a microwave oven.”

Proxima’s “dumb machine” is named Alpha. It builds on decades of research from Germany’s Max Planck Institute for Plasma Physics, including their stellarator W7-X. The goal of Alpha is to generate more energy than it consumes, with insights from its development helping shape the next stage: Stellaris, a full-scale fusion power plant.

Funding and Competition

Alpha’s success hinges on substantial investment. Proxima recently secured €400 million from Bavaria and is seeking over a billion dollars in federal funding, with a decision anticipated next year. They are not alone in this race—53 groups worldwide are developing fusion technology, according to the Fusion Industry Association. One such project, Step, uses the tokamak approach. Backed by the UK government, Step plans to build a prototype at a former coal-fired site in West Burton, Yorkshire.

“Tokamaks have the advantage of a deep experimental foundation built over decades,” explains Ryan Ramsey, director of Organisational Performance at Step. “They have demonstrated plasma performance closer to what’s required for a fusion power plant, including operation with fusion fuel.”

Ramsey also highlights the cost benefits of tokamaks. “They benefit from comparatively simpler magnetic geometry, with fewer and more regular coils,” he adds. “That has real implications for manufacturability, maintainability, and cost.” However, Sciortino remains cautious. “The first magnet we make will be very complicated and very expensive,” he admits. “But can we make it faster than people would expect, and can we drive down the cost?”

Germany’s Engineering Edge

Sciortino points to Germany’s manufacturing expertise as a key strength. He notes the country’s vast pool of CNC machinists—over 550,000 in total—who can shape materials with precision. This workforce is critical for producing the intricate magnets required for stellarators, which Proxima aims to optimize. While the road to fusion energy is arduous, the fusion of innovation and industrial capability may finally turn the dream into reality.