A researcher working on a section of the Wendelstein 7-X, an experimental nuclear fusion reactor in Greifswald, Germany, on Nov. 19, 2021. Credit - Stefan Sauer—Picture Alliance/Getty Images
One of my favorite bar signs is the one that promises “Free beer tomorrow.” That’s how I’ve always thought of nuclear fusion—a (theoretically) cheap, pollution-free and inexhaustible energy source, the promise of which has pretty much been a decade away ever since the technology was first tested 70 years ago.
When “nuclear energy” is discussed, it’s almost always in reference to nuclear fission, which generates energy by splitting atoms—and is the source of power for nuclear weapons and all of the nuclear generators in operation today.
Nuclear fusion, on the other hand, occurs when two positively charged nuclei merge. It’s the same kind of reaction that powers our sun—sparked by the star’s massive size, heat and gravitational fields. To recreate that reaction on earth requires heating gasses to more than 100 million degrees Celsius and holding them in place with lasers or powerful magnets. That heat and compression overcomes the forces that would otherwise keep the positively-charged nuclei apart, and they fuse together. That fusion releases energy, and if maintained, the ongoing reaction creates more energy than it consumes.
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Electricity generated through fusion has no emissions, minimal waste, and there is no risk of out-of-control meltdowns like Chernobyl. The fuel, derived from helium or hydrogen, is cheap and plentiful.
That’s the theory.
In practice, no one really knows. Forcing two nuclei to merge takes enormous amounts of heat and energy, and in the rare instances where it has worked, the energy produced has more often than not been less than the amount required to launch, and maintain, the fusion action in the first place. In order to generate power, the reaction would need to be self-perpetuating. For the scientists pursuing the atomic equivalent of tomorrow’s free beer, launching a self-sustaining fusion reaction is still tantalizingly out of reach.
But it is getting closer.
New advances in 3D printing (necessary for manufacturing equipment with hollow cavities), supercomputing (to calculate mass and energy), and material sciences (super thin, super-powerful magnetic tape) have led to a number of essential breakthroughs in recent months. In August, scientists at California’s Lawrence Livermore National Laboratory set a record for nuclear fusion energy production, even if the blast lasted a fraction of a second. Meanwhile, the mounting urgency of the climate crisis, which is caused by fossil fuel emissions, has sparked investor interest in green alternatives. On Nov. 5, fusion start-up Helion Energy announced that it had raised $500 million in its most recent fundraising round, the largest ever for a private fusion firm. The company expects to achieve net positive electrical generation by 2024. “Modern advancements in electronics enable us to do fusion decades sooner than previously imagined,” David Kirtley, the CEO and founder of Helion Energy said in an email.
All told, some 35 fusion-focused start-ups have raised nearly $2 billion in private investments, according to the 2021 Global Fusion Industry Survey, published jointly by the U.K. Atomic Energy Agency and the Fusion Industry Association.
“Fusion was always 10 years to forever away. It was about science; it was about research,” says Jane Hotchkiss, a 30-year veteran of the renewable energy industry, who now heads up Energy for the Common Good, an NGO that advocates for the development and use of fusion technology as a clean energy solution. “Now that we have a new generation of commercially focused physicists and engineers racing to put it into practical use, there is hope for the future.”
Unlike solar or wind power, which require both battery backup and electrical grid adaptations to account for variations in energy supply (think cloudy/windless days), fusion power plants could be easily swapped in for existing coal- or gas-burning plants with little adjustment to the larger grid, because they can run continuously. The immense power generated could also be used to produce green hydrogen, an emissions-free, energy-dense fuel that could help decarbonize shipping, aviation and transport.
The problem is the distance between what it could do, and what it is currently doing— which is mostly making promises about what will happen tomorrow.
The technological challenges of creating what is essentially a sun in a bottle still requires major investment, beyond even what venture capitalists are willing to commit, says Hotchkiss. “Fusion is the planet’s moon shot to climate change solutions. We have to stop treating it like a scientific research project and treat it like a future commercial product.” That means government buy-in as well.
That is starting to happen: The U.K. government has already invested $250 million in a fusion reactor that it hopes will start generating power by 2040. And ITER, a $25 billion multinational fusion project in France, is due to begin operations in 2025. Meanwhile, the U.N. climate conference in Glasgow earlier this month served as a kind of coming out party for fusion: for the first time, the technology was granted center stage at a roundtable discussion held on the last day, and a fusion exhibit at the Glasgow Science Center invited non-delegates to learn more.
Attention couldn’t be coming soon enough, says Hotchkiss. According to the International Energy Agency, the projected energy produced by renewables in 2022 is only enough to meet half of global demand. The rest will have to be met by traditional fossil fuel sources. “It’s time to take fusion seriously. It offers too many solutions for what is wrong with energy today.” That free beer is meeting its due date.