Tapping into an almost inexhaustible source of energy with lasers – that sounds like science fiction. Just over a year ago, this promise made headlines around the world. On December 5, 2022, US researchers merged atomic nuclei and generated more energy than they had put directly into them using lasers. US Energy Secretary Jennifer Granholm called it “one of the most impressive scientific achievements of the 21st century.”

Suddenly politicians in Germany were increasingly talking about nuclear fusion. Federal Research Ministry Bettina Stark-Watzinger (FDP) recently announced investments of more than one billion euros for the next five years. The topic is fashionable.

“I can confirm that,” says Thomas Klinger, head of the “Wendelstein 7-X” fusion experiment at Greifswald, to the German Press Agency. “There have already been very significant advances in fusion research, which encourage the general public that this is not a pipe dream that will be tinkered with forever.” “Wendelstein 7-X” also achieved a milestone at the beginning of the year. It was possible to maintain a plasma – a kind of fourth state of matter required for nuclear fusion – very hot and for a long time.

During nuclear fusion, atomic nuclei are fused – i.e. fused – at extreme temperatures. This also happens in stars and therefore also in the sun. Scientists rely on lasers or magnets. Theoretically, enormous amounts of energy could be generated – in a climate-neutral manner, without the risk of a reactor catastrophe as with nuclear fission and without long-lived and highly radioactive waste. So far, this is a thing of the future, despite decades of research.

Roth: Private investments worth billions

“Artificially creating a star on Earth, keeping it alive and milking it” is the most complicated thing humans have ever attempted, says Markus Roth from the Technical University of Darmstadt. “If it were rocket science, we would have done it by the ’60s.”

In the experiment in the USA, as is usual in research, only the energy balance of the plasma itself was taken into account – but not the overall balance. It is crucial for future electricity generation that it is positive, which it is still far from being. According to information at the time, the facility required approximately 300 megajoules of energy to deliver two megajoules of laser energy, which produced three megajoules of fusion yield. It should also be taken into account that the energy generated is thermal; when it is transferred into electricity, there are usually large losses.

The German-American start-up Focused Energy, co-founded by Roth, wants to make laser fusion usable. Several researchers who were involved in the breakthrough a year ago in the USA are involved. You have already been invited to the White House and are part of a US funding program. According to Roth, a growing number of start-ups are stimulating development. Some of the companies have already raised billions in private investments.

The management consultancy Strategy

But money alone is of no use, says Klinger. What is needed is an appropriate environment, which also includes industry. “There is no fusion industry in that sense. It is slowly starting to form.” For this to happen, prototypes would actually have to be developed and systems built. This sparring effect is important.

Kemfert: Current mini-successes

According to its own information, the company Gauss Fusion is the only one of the approximately 40 existing nuclear fusion companies, mainly from the USA, that comes from industry and not from research. Bringing fusion online is no longer a physical problem, but an engineering one, says managing director Milena Roveda. Their goal: to build a power plant in Europe by the early 2040s. Cost: 20 billion. After that the costs would decrease. The money will come from public and private sector donors.

“Other technologies are cheaper and faster than nuclear fusion,” criticizes Claudia Kemfert, energy expert at the German Institute for Economic Research (DIW). When it comes to the promises of nuclear fusion, there is “more desire than reality at play.” She talks about current mini-successes. Until nuclear fusion is ready, renewable energies could enable full supply.

Heinz Smital, a nuclear expert at Greenpeace, also believes the “new hype” surrounding nuclear fusion is very problematic. “It results in massive amounts of money being poured into a technology that will bring little benefit to society.” In addition to promoting renewable energies, the billion promised by the federal government should be invested in the digitalization of energy networks and storage.

Klinger acknowledges that fusion energy is more likely to play a role in the second half of this century. “To be honest, I don’t think that’s a bad thing.” It is wishful thinking that golden times in energy will dawn after 2050. There are underserved regions of the world and removing greenhouse gases from the atmosphere will require a lot of energy. For Roth, it is also about energy independence: In the future, we will also be dependent on other regions of the world for the supply of solar energy or hydrogen. Nuclear fusion could help.

Klinger believes that the first fusion power plant could be in place by the middle of the century. “I think that’s definitely doable without being on shaky ground.” If you start straight away, it might be possible to do it in 20 years – with a little more risk, because fewer technical questions would then be clarified in advance. “It remains difficult. We are always at the limit of what is technically possible.” But in general, Klinger is optimistic. “Not unrestrainedly optimistic, but optimistic. It should work. That’s the best thing a scientist can say.”