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Nuclear fusion - hype or solution to energy problems?

Nuclear fusion could solve many energy problems - or so the promise goes. More and more start-ups are working on this alongside research institutes. Critics are skeptical about the latest hype.

View of the "Wendelstein 7-X" research reactor at the Max Planck Institute for Plasma Physics.....aussiedlerbote.de
View of the "Wendelstein 7-X" research reactor at the Max Planck Institute for Plasma Physics. Photo.aussiedlerbote.de

Research - Nuclear fusion - hype or solution to energy problems?

Using lasers to tap into an almost inexhaustible source of energy - that sounds like science fiction. Just over a year ago, this promise made headlines around the world. On December 5, 2022, US researchers fused 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 also increasingly talking about nuclear fusion. Federal Research Ministry Bettina Stark-Watzinger (FDP) recently announced investments of more than one billion euros over the next five years. The topic is in vogue.

"I can confirm that," says Thomas Klinger, head of the "Wendelstein 7-X" fusion experiment near Greifswald, to the German Press Agency. "There has already been very significant progress in fusion research, which encourages the general public that this is not a castle in the air that will be tinkered with forever." Wendelstein 7-X also achieved a milestone at the beginning of the year. It succeeded in maintaining a plasma - a kind of fourth state of matter required for nuclear fusion - very hot and for a long time.

In nuclear fusion, atomic nuclei are fused at extreme temperatures. This also happens in stars and therefore also in the sun. Scientists use lasers or magnets to achieve this. Theoretically, enormous amounts of energy could be generated - in a climate-neutral way, without the risk of a reactor catastrophe as with nuclear fission and without long-lasting and highly radioactive waste. So far, this is a dream of the future, despite decades of research.

Roth: Private investment in the 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 back in 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. For future electricity generation, it is crucial that this is positive, which it still is far from being. According to the information provided at the time, the system required around 300 megajoules of energy to supply two megajoules of laser energy, which generated three megajoules of fusion yield. It should also be borne in mind that the energy generated is thermal, and there are usually major losses when it is converted into electricity.

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 also involved. They 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 attracted private investment in the billions.

In September, the management consultancy Strategy& warned that Germany could fall behind due to lower investment than abroad, despite top-level research.

But money alone is useless, 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." Prototypes actually have to be developed and plants built for this. This sparring effect is important.

Kemfert: Current mini successes

According to the company, Gauss Fusion is the only one of the 40 or so existing nuclear fusion companies, mainly from the USA, that comes from industry and not research. Bringing fusion to the grid is no longer a physical problem, but an engineering one, says Managing Director Milena Roveda. Her goal: to build a power plant in Europe by the early 2040s. Cost point: 20 billion. After that, the costs would fall. The money is to 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). The promises of nuclear fusion are "more wishful thinking than reality". She speaks of current mini-successes. Until nuclear fusion is ready, renewable energies could provide a full supply.

Heinz Smital, nuclear expert at Greenpeace, also considers the "new hype" surrounding nuclear fusion to be very problematic. "It is leading to massive amounts of money being invested in a technology that will bring little benefit to society." The billions promised by the German government should rather be invested in the digitalization of energy grids and storage alongside the promotion of renewable energies.

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 terms of energy will dawn after 2050. There are undersupplied regions of the world and the removal of 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 provide a remedy.

Klinger believes that the first fusion power plant could be built by the middle of the century. "I think that's definitely feasible without standing on too shaky a foundation." If you get started right away, it may also be feasible in 20 years - with a little more risk, because fewer technical questions would be clarified in advance. "It remains difficult. We are always at the limits of what is technically feasible." But Klinger is generally optimistic. "Not unrestrainedly optimistic now, but optimistic. It should work. That's the best a scientist can say."

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Source: www.stern.de

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