Frank Laukien, a U.S.-German physicist and billionaire entrepreneur, typically exudes the calm rationality of a CEO who runs a large, multinational company. In his long career, he has turned his Bruker Corporation, based outside of Boston, into one of the world’s leading manufacturers of scientific instruments.
But when Laukien was recently handed the microphone at Forum Fusion, an annual get-together of scientists, engineers, and business people in Berlin, he sounded exuberant. Within 20 years, he pronounced, scientists would be able to emulate the process that fuels the sun and use it to generate infinite green energy on Earth. “If we really want a fully renewable energy supply, we need fusion as a third pillar,” Laukien said, in addition to wind farms and solar panels. “Fusion is the key to a decarbonized future.”
Observers could be forgiven for reacting to Laukien’s claims with skepticism. Fusion has been talked about for so long, and has faced such daunting challenges, that its realization — if it is realized at all — has always seemed extremely far off in the future. Even pursuing it, some critics felt, was a distraction from taking more immediate action to lower greenhouse gas emissions.
More than $4.7 billion has been injected into fusion energy start-ups, according to an industry survey.
But recent technological breakthroughs in the United States and Britain — coupled with heightened insecurities over global energy supplies — are refocusing attention on fusion. Last December, scientists at Lawrence Livermore National Laboratories, in California, achieved fusion ignition — the point at which a nuclear fusion reaction becomes self-sustaining. In late 2021, scientists at the Joint European Torus, a research facility in the U.K., produced a plasma that generated 11 megawatts of power over a short, but significant, period of time. Funding has begun flowing to private fusion companies from the U.S. Department of Energy and the German and U.K. governments, among others. Private investors have invested large sums in these companies, too. Altogether, more than $4.7 billion has been injected into fusion energy start-ups, according to a 2022 survey by the Fusion Industry Association.
Scientists have been studying nuclear fusion — which makes energy by combining atoms, as opposed to nuclear fission, which splits them — since the 1950s. But the prospects for building an actual power plant were seen as so small, and the expected costs so high, that research and development were left to government-funded projects. Failures and delays were so ingrained they inspired an oft-quoted joke: “Do you know the fusion constant?” “Success is always 30 years away.”
The world’s largest fusion project, the International Thermonuclear Experimental Reactor (ITER), was initiated by Ronald Reagan and Mikhail Gorbachev in 1985. The project is run — very slowly — by 35 governments, and the reactor, which is still under construction in Cardache, in the south of France, has yet to deliver any tangible results.
But today, a growing cadre of entrepreneurs and scientists believe that a different approach is necessary, and that smaller, more nimble private companies stand a better chance of producing an actual fusion reactor. “Fusion research was very successful in the past two years, and we are getting closer to the vision of an inexhaustible source of energy,” says Sibylle Günter, director of the Max Planck Institute for Plasma Physics, in Germany.
Frank Laukien recently joined a group of so-called “deep tech” entrepreneurs to found Gauss Fusion, named after the German mathematician. The company brings together top-notch scientists and high-tech firms from Italy, Spain, France, and Germany with expertise in all fields relevant to fusion — from magnets to surface materials.
Gauss is just one of more than 30 companies to start up in recent years, all of them competing in the global race to deliver fusion energy. Projected timelines differ. Microsoft has contracted to buy 50 megawatts of fusion electricity from U.S.-based start-up Helion, which claims it will deliver the power in 2028. The deal is widely considered to be a publicity stunt, since having a grid-ready fusion reactor within five years is deemed highly unlikely. Other companies are claiming they will deliver a prototype reactor in the early 2030s.
The price tag for a 1,000-megawatt fusion plant could range from $2.7 billion to $9.7 billion, according to Princeton University researchers. Laukien has calculated a cost of about $11 billion for a commercial power plant that generates 2,000 to 3,000 megawatts.
The U.S. Energy Secretary called a recent breakthrough in laser fusion “one of the most impressive scientific feats of the 21st century.”
In 2021, Tony Donné, the CEO of EuroFusion, an organization that brings together the continent’s leading fusion research institutions, told Nature, “Private companies say they’ll have it working in ten years, but that’s just to attract funders.” Earlier this month, at Forum Fusion, he captured this new optimism by telling the audience, “We need to join venture capitalist speed and the holistic views of public research.”
Both nuclear fission and nuclear fusion employ energy-rich neutrons to heat water. The resulting steam powers turbines that generate electricity. But the methods are fundamentally different. In nuclear fission, large uranium atoms are split to cause a chain reaction that sets the neutrons free. In nuclear fusion, two atoms of hydrogen are forced to unite and turn into one helium atom. This process also sets neutrons free for heating water, but with major differences.
Where nuclear fission reactors can melt down and release massive amounts of radiation, nuclear fusion reactors, if disturbed, simply shut down. Nor do nuclear fusion reactors amass highly radioactive spent fuel that requires long-term storage. One fuel component, a hydrogen isotope called deuterium, which is not radioactive, is widely available in nature. The second hydrogen isotope needed, tritium, is extremely rare, but it can be chemically produced and recycled within the reactor by bringing it into contact with lithium embedded in the chamber walls. Fusion proponents claim a single gram of fuel can supply as much energy as 11 tons of coal — with zero CO2 emissions.
In December of 2022, scientists from the Lawrence Livermore National Laboratory (LLNL) made international headlines by initiating the fusion of hydrogen into helium with energy from a powerful laser. They were able to yield slightly more energy than was required to start the process. LLNL director Kimberly Budil described this outcome as a “truly monumental” first step that “sets the stage for a transformational decade“ in fusion research. U.S. Energy Secretary Jennifer Granholm hailed the achievement as “one of the most impressive scientific feats of the 21st century.”
Robin Grimes, a professor of materials physics at Imperial College London who was not involved in the experiment, called it “a key step on a possible pathway to commercial fusion” and an “an engineering triumph.”
Laser fusion works by shooting powerful beams at frozen pellets of hydrogen with high frequency. Grimes and other scientists point out, though, that massive challenges remain. “Although positive news, this result is still a long way from the actual energy gain required for the production of electricity,” said Tony Roulstone, a lecturer in nuclear energy at the University of Cambridge. While yielding 3.15 megajoules of energy output with an energy input of 2.05 megajoules was a success, he said, powering the whole experimental device required 400 megajoules of power (enough energy to run 10 U.S. households for a year) for the five-microsecond experiment.
“Laser fusion holds many promises but still has many technological challenges to resolve,” a scientist notes.
For fusion to work commercially, Roulstone added, the process would have to be scaled up, achieving “an energy gain of double [what] went into the lasers,” a goal that’s still far off. Others point out that Lawrence Livermore produces its strong energy shot only once a day, and “a fusion power plant would need to do it 10 times per second,” according to Justin Wark, a professor of physics at the University of Oxford who was not involved in the experiment.
This is what Focused Energy, which has labs and offices in Austin, Texas, and Darmstadt, Germany, promises to deliver. The company says it plans to build a laser-fusion demonstration facility in Hesse, Germany, between 2028 and 2030. And it is aiming to launch the first demonstration power plant that feeds electricity into the U.S. grid, in Austin, in 2037. The plant, called SuperNova, would have a planned power capacity of 300 to 500 megawatts.
Focused Energy was one of eight companies to share $46 million in funding from a recent U.S. Department of Energy competition; it also received the equivalent of almost $50 million in funding from SPRIN-D, the German government agency in charge of advancing breakthrough innovations.
Some experts believe Focused Energy’s timeline is unrealistic. “Laser fusion holds many promises but still has many technological challenges to resolve,” said Constantin Haefner, director of the Fraunhofer Institute for Laser Technology in Aachen, Germany. “It takes 12 to 15 years to build a power plant, and before that, it will take several more years to make the technology of nuclear fusion ready for application.”
Like Haefner, Laukien is broadly optimistic about fusion’s prospects, but he doubts anyone will deliver laser fusion energy before the 2040s. Laukien and Gauss Fusion are betting instead on a far older — and more tested — technology called magnetic-confinement fusion, and they plan to build their reactors within Germany’s derelict coal and nuclear fission power plants.
In magnetic fusion, a large reaction chamber is surrounded by powerful magnets. Inside, hydrogen gas is heated to a point of forming plasma. This cloud of charged particles, which reaches more than 150 million degrees Celsius, is held in place by the magnets and by a vacuum, so it never touches the walls. The goal is to increase heat and pressure until it induces fusion and yields more energy than is used to create the plasma in the first place. In the case of ITER, which will use this technique, the goal is to get 500 megawatts of power, the equivalent of a medium-sized coal-fired power plant, from an input of 50 megawatts.
Like laser fusion, magnetic confinement fusion has seen some recent breakthroughs. Scientists at the Joint European Torus (JET), a research facility in Culham, U.K., managed to produce a plasma in December 2021 that delivered 11 megawatts over a period of five seconds: a new world record.
No matter when these start-ups cross the finish line — if they do — it’s likely to be well ahead of ITER, the world’s largest, and longest-running, fusion project. ITER’s first serious goal was to create a stable plasma and maintain it for longer than 400 seconds. Originally, it aimed to achieve this target in 2018, but in late 2022 scientists and engineers building the large reaction chamber discovered defects in its welding and its thermal shields.
“Nuclear fusion comes too late to help in the climate crisis,” says a climate scientist.
Fixing these flaws could take years, according to scientists involved in the projects. And ITER isn’t even supposed to produce electricity for the grid: its task is merely to demonstrate the technology that will eventually pave the way for an actual power plant, to be called DEMO. Support for completing ITER is unanimous among the scientists involved, but EuroFusion, the intergovernmental body that represents ITER’s research organizations, now proposes jumping directly to the DEMO power plant. Donné, EuroFusion’s CEO, suggests building a smaller, dedicated testing facility to address the largest remaining challenge: finding a way to recycle tritium within the reactor’s chambers so the plant can provide most of its own fuel.
Fusion start-ups argue that ITER’s primary stumbling block is not science or the technology itself, but the intricate challenge of aligning bureaucracies across 35 nations and mobilizing sufficient financing from governments. They claim that start-ups, with their lean structures and private funding sources, can do a better job.
“The benefit of being a smaller organization is we can be faster and more agile,” said Stuart White, of Tokamak Energy, a fusion start-up based near Oxford, U.K., whose prototype, which occupies a 107,000-square-foot building, has already reached a plasma temperature of 100 million degrees, the threshold for commercial fusion. The company’s devices are orders of magnitude smaller and cheaper than ITER. As such, White claims, they will be much quicker to build as commercially deployable energy sources.
But given the challenges remaining, and the uncertain timelines, some scientists caution against pursuing fusion as an energy source. “Nuclear fusion comes too late to help in the climate crisis,” said Stefan Rahmstorf, a climate scientist who co-heads the Research Department on Earth System Analysis at the Potsdam Institute for Climate Impact Research. He believes all resources should be spent on renewable energy and energy efficiency.
Fusion scientists and entrepreneurs agree that nothing should stop governments from greatly expanding renewables. “We must focus on 100 percent renewable energy sources and achieve this by 2045,” said Haefner, citing the European Union’s zero emissions tipping point for averting irreparable damage. But he points out that demand for electricity will continue to rise after that year.
“If we want to permanently cover our heating needs and the need for fuels for trucks and aircraft, for example, with electricity,” Häfner said, “then we would do well to establish a source of electricity that is always available.”
Frank Laukien goes even further. He has set his sights on a task the International Panel on Climate Change has described as central to avoiding catastrophic climate impacts: achieving so-called negative emissions. We need to not only quit burning fossil fuels, but also to capture carbon dioxide directly from the atmosphere, Laukien says. “And we need fusion energy to do that.”