This article is part of the Debatable newsletter. You can sign up here to receive it on Wednesdays.
When researchers at Lawrence Livermore National Laboratory in California announced last week that they had achieved the first controlled nuclear fusion reaction to produce more energy than it took to start, they brought humanity one step closer to the decades-long dream of harnessing the power of the sun — not by absorbing its rays from 93 million miles away, as solar panels do, but by igniting, in effect, a miniature star on earth.
The Biden administration has said that it aims to make commercial fusion energy a reality by 2032, in the hopes that the still-speculative technology could help wean the United States off fossil fuels and reach net-zero emissions by 2050. “This shows that it can be done,” said Energy Secretary Jennifer Granholm.
But the history of nuclear fusion is long and riddled with false starts and hopes. Is this time really different, and what are the chances that it could play a meaningful role in the global effort to halt climate change? Here’s what people are saying.
The ‘holy grail’ of fusion
Scientists have been thinking about how to harness fusion ever since the process was first demonstrated in the 1930s. Like fission, the nuclear reaction that powers today’s nuclear plants, fusion produces emissions-free electricity, but without the long-lived toxic byproducts or risk of catastrophic accidents.
While the splitting of atoms in a fission reactor can become self-sustaining, risking meltdown if not precisely controlled, the fusing of atoms can happen only under conditions that are very difficult to maintain; any disturbance to a fusion reactor would cause the process to stop.
Fusion does create radioactive waste, like fission, but it is less hazardous and could be recycled within 100 years, instead of necessitating storage deep underground for tens of thousands of years.
Fusion also yields several times more energy by weight than fission and millions times more than the combustion of fossil fuels: A few paper clips’ worth of reactants (isotopes of hydrogen, the most abundant element in the universe) could produce enough energy for a person’s lifetime.
In theory, fusion could have distinct advantages over other renewable energy sources. It would require less land than solar and wind farms, a frequent reason for local opposition to construction, and could deliver electricity around the clock without long-term storage, which remains beyond the capabilities of current battery technology. And as a nearly limitless source of power, proponents say it could help solve some of humanity’s most urgent problems beyond climate change, like poverty (by removing a major barrier — lack of access to clean, reliable electricity — to economic development) and clean water scarcity (by providing the enormous amounts of energy needed to desalinate seawater).
But for fusion to happen on earth, the fuel has to be heated to more than a hundred million degrees Celsius — hotter than the core of the sun — which poses extraordinary engineering challenges. One reactor design approach, used by the world’s largest fusion facility, an international project located in France, involves containing plasma with giant magnets strong enough to lift an aircraft carrier and chilled almost to the temperature of deep space. Another approach, used by Livermore, involves bombarding a tiny pellet of fuel with an arsenal of the world’s most powerful lasers.
Until now, no approach had been able to produce more energy from a reactor than it consumed, long identified as the technology’s proof of concept. “That is a true breakthrough moment which is tremendously exciting,” Jeremy Chittenden, a professor of plasma physics at Imperial College London, said of the Livermore achievement. “It proves that the long sought-after goal, the ‘holy grail’ of fusion, can indeed be achieved.”
Commercial fusion in a decade?
As significant as last week’s announcement was, huge technological and economic hurdles still have to be cleared before fusion reaches true viability. For one thing, the lasers that powered the Livermore experiment are terribly inefficient, so while the reaction did produce more energy than the lasers delivered, it still fell far short of the energy that the lasers needed to draw from the grid to operate. For another, the pellet-sized fuel targets each cost thousands of dollars to manufacture. A commercial fusion power plant would require much more efficient, faster-firing lasers and targets that cost only about 25 cents.
“This result is miles away from actual energy gain required for the production of electricity,” Tony Roulstone, a fusion expert at Cambridge, told CNN. “We can say (it) is a success of the science but a long way from providing useful energy.”
But some are hopeful that with enough funding, the pace of fusion’s development could accelerate. In the 1970s, the U.S. Energy Research and Development Administration predicted that commercial fusion could be realized by 1990 with $9 billion in yearly investment, while yearly investment of $1 billion or less would lead to “Fusion Never.” “And that’s about what’s been spent,” Steven Cowley, a British physicist, told The New Yorker last year. “Pretty close to the maximum amount you could spend in order to never get there.”
If investors now perceive fusion as having taken a leap forward, from a fantasy to a potential, highly profitable reality, that stagnation could finally break. “The timeline is the function of the will we have and the amount of investment that society puts forth and the number of people who get excited and want to work on these challenges,” Sam Wurzel, the technology-to-market adviser at ARPA-E, told my colleague Peter Coy. “The excitement is at a level I’ve never seen.”
That’s true of Congress, which recently increased its funding for fusion research and construction. And it’s also true of investors in the private sector, where dozens of fusion start-ups have sprouted up with $5 billion worth of help from the likes of Bill Gates, Jeff Bezos and Peter Thiel.
Most of these companies hope to provide fusion electricity to the grid sometime in the 2030s. “It will take hard work and innovation, but this is what we do in the U.S. — so I think it is possible to meet this goal and the fusion research community is ready to roll up our sleeves and make it happen,” said Troy Carter, a plasma physicist at the University of California, Los Angeles.
The case for skepticism
Among physicists, there is an old joke that fusion is 50 years away — and always will be. The Livermore breakthrough undercuts the punchline somewhat, but Kimberly Budil, the lab’s director, still estimates that a fusion power plant is “probably decades” away. “I think not five decades, which is what we used to say,” she said, but “a few decades of research.”
The Livermore experiment has been compared to the Wright brothers’ first flight, but to Charles Seife, the author of “Sun in a Bottle,” it’s less “like a Kitty Hawk moment than a lab experiment demonstrating that air flowing over a wing can produce a little bit of lift,” as he writes in The Atlantic. “The work doesn’t address any of the myriad other scientific, technical, and design problems that would need to be solved before we really can take off from the ground and claim that we’ve produced more energy with fusion than we’ve consumed.”
In the meantime, given the urgency of drawing down greenhouse gas emissions now, many climate scientists, policymakers and activists say we should focus on scaling up the renewable energy technologies already available.
“Imagine, if everything goes right, a world where, in a quarter-century’s time, we can take down the solar panels and wind turbines we’re now erecting and replace them with elegant fusion reactors,” writes Bill McKibben in The New Yorker. “If we don’t make that first transition right now, those elegant reactors will be deployed, if at all, on a badly degraded, even broken, planet.”
And in a world of finite resources, too much faith and investment in fusion could come at the expense of that first transition. “Part of the rationale for financing this hugely expensive technology rests on an assumption that the world will fail to sufficiently stem its carbon emissions,” writes India Bourke in The New Statesman. “Preparing for the worst could risk making it inevitable.”
For many, the optimal climate strategy requires aggressively deploying the technologies humanity has while still chasing the ones humanity dreams of — not either-or, but all-of-the-above. “Investing in nuclear fusion now will not make the next few decades of an accelerating climate crisis any easier,” writes Sabine Hossenfelder, a theoretical physicist, in The Times. “But after all the damage that our short-term thinking has done to this planet, let us think past 2050, and show our children that we care.”
Do you have a point of view we missed? Email us at firstname.lastname@example.org. Please note your name, age and location in your response, which may be included in the next newsletter.
“A hole in the ground could be the future of fusion power” [MIT Technology Review]
“The Chase for Fusion Energy” [Nature]
“Fusion power is tantalizing, but it won’t save the planet” [The Washington Post]
“A plasma physicist explains what’s next after this week’s nuclear fusion breakthrough” [The Verge]