German start-up wins initial funding for revolutionary fusion energy machine

A German start-up has secured initial funding to develop a revolutionary fusion energy machine that it hopes can provide a future source of abundant, emissions-free power.

Proxima Fusion, incorporated in January, aims to build a complex device known as a stellarator and is the latest company to join the emerging fusion industry’s effort to generate electricity by fusing atoms.

Although the amount of funding is small at only €7mn, it is significant as Proxima is the first fusion company to spin out of Germany’s revered Max Planck Institute for Plasma Physics.

The institute is the home of the world’s most advanced existing stellarator in Greifswald, in eastern Germany, built by government-funded scientists over the past 27 years using supercomputers and advanced engineering.

Little known outside the world of plasma physics, a stellarator is an alternative to the better known tokamak device, pioneered by Soviet scientists in the 1950s.

Both use huge magnets to suspend a floating mass of hydrogen plasma as it is heated to extreme temperatures so the atomic nuclei fuse releasing energy.

Until recently nearly all funding of so-called magnetic confinement fusion has been channelled into tokamaks such as the Joint European Torus in Oxford, England, or the Sparc device being built by the Bill Gates-backed Commonwealth Fusion Systems in Massachusetts.

The twisted structure of the stellarator is more complicated to design and build than a traditional tokamak but produces a more stable plasma that could enable scientists to sustain the fusion reaction for longer.

“A tokamak is kind of easy to design, hard to operate, whereas a stellarator is super hard to design but once you’ve designed it, it’s way easier to operate,” said Ian Hogarth, co-founder of Plural Platform, which is leading the €7mn investment alongside Germany’s UVC Partners.

The stellarator was conceived by the American physicist Lyman Spitzer in 1951 but largely abandoned after tokamak breakthroughs in the 1960s appeared to offer an easier route to fusion. Germany was one of a small number of countries that persevered with stellarator research, starting work on the Wendelstein 7-X at the Max Planck Institute in 1996, at a total cost to date of €1.3bn.

“During the building of the machine, we learned how to build the machine,” Thomas Klinger, director of the institute’s Greifswald branch since 2001, told the Financial Times. The final design was the product of “tedious and exhausting research”, he added.

Then-chancellor Angela Merkel turned on the W 7-X for the first time in 2016 and the machine has since achieved a series of scientific breakthroughs.

“They’ve basically done the impossible,” said Hogarth. “With 1990s computing resources they successfully designed a stellarator . . . and now it’s setting records that basically are defining the whole field of magnetic confinement fusion.”

The close relationship between Proxima and the Max Planck Institute has invited comparisons with Commonwealth Fusion, which was spun out of the Massachusetts Institute of Technology in 2018 and has since raised a record $2bn from investors.

“We’re connected to an institution, which has more people [working on plasma physics] than MIT,” said Proxima chief executive Francesco Sciortino, who worked at the Max Planck Institute before setting up the company. “The question is, can we execute just as well, and really make this a European champion?”

Despite the achievements of the W 7-X, Klinger said there was a long road from there to commercial power, which he cautioned could still be 25 years away.

While advances in materials science and a flood of private investment have raised hopes that abundant, emissions-free fusion energy can be connected to the grid by the 2030s, a fusion machine is yet to produce more energy than the system itself consumes.

Philippe Larochelle at Bill Gates’s Breakthrough Energy Ventures, which has made four fusion investments, has backed both Commonwealth Fusion’s tokamak and a stellarator concept being developed by US-based Type One.

“The idea of fusion is that the prize is so big that this is worth multiple shots on goal,” he said.