The announcement of the experimental success came bracketed by cautionary notes. It may be many more years before this technology can be employed for everyday use. This was a science experiment more than a demonstration of a practical technology.
Still, it was the first time anyone had managed to create net energy gain. The experiment delivered 2.05 megajoules of energy to the lasers’ target and resulted in 3.15 megajoules of energy output, officials said. Basically, two in, three out.
“This is a landmark achievement,” Energy Secretary Jennifer Granholm said at department headquarters Tuesday. The department runs the Livermore lab and its National Ignition Facility, where the experiment took place. “This milestone will undoubtedly spark even more discovery. … This is what it looks like for America to lead.”
In an indication of the challenges that lie ahead for actually applying the technology, the results did not account for the 300 megajoules of energy it took to create the lasers in the first place.
This is not the only experiment underway for generating fusion, and there’s something of a race to see which method works best. For decades, the field has been dominated by fusion experiments involving powerful magnets rather than lasers.
“I’m not sure magnetic fusion is going to beat [laser] fusion,” said Steven Cowley, director of the Department of Energy’s Princeton Plasma Physics Laboratory, which uses magnets in its fusion experiments. “I think fusion is so important we should have at least two technologies vying for completion. One of them is going to end up the airplane, and one of them is going to end up the Hindenburg.”
The Biden administration is aggressively pushing investment in clean energy technologies, like fusion, that are still years away from practical deployment. Scientists caution that while fusion energy holds potential to provide round-the-clock electricity without the pollution or radioactive risks of traditional coal, gas and nuclear power plants, it would be a long time before any of it is brought to the grid.
“Probably decades,” said Kim Budil, director of the Lawrence Livermore laboratory. “Not five decades, which is what we used to say. I think it’s moving into the foreground. And probably with concerted effort and investment, a few decades of research on the underlying technologies could put us in a position to build a power plant.”
The reaction that scientists produced at the National Ignition Facility required the firing of an immense laser system that was built only after massive cost overruns and years of delays. The development touched off a new round of debate about how far government should go in incubating multibillion-dollar long-shot technologies that may never get put to use commercially — but could change the world if they make it to market.
Generating electricity from nuclear fusion would require the kind of reaction reported Tuesday, called “ignition,” every second throughout the day. Getting there would be a monumental engineering feat; just producing a fraction of a second of net energy gain, as the Livermore lab experiment did, creates so much stress on the costly machinery that the process tends to break it.
The nation’s fusion program was initially created with the goal of more efficient management of the U.S. nuclear weapons stockpile. Fusion reactions could be used to assess those arms without the need for explosions, which create radioactive fallout. Biden administration officials hailed the developments at the Lawrence Livermore lab as a major boost for their efforts to keep the stockpile safe and reassure allies that the United States is capably managing it.
“It underpins the credibility of our deterrent by demonstrating world-leading expertise in weapons-relevant technologies,” said Marvin Adams, deputy administrator for defense programs at the National Nuclear Security Administration. “That is: We know what we are doing. Continuing to assure our allies that we know what we are doing and continuing to avoid testing will advance our nonproliferation goals, also increasing our national security.”
Commercial fusion energy has been a fringe pursuit for years, amid disappointing results in national laboratories and constant threats that the funding for fusion experiments would be canceled.
Tammy Ma, a physicist at the National Ignition Facility, said she “burst into tears” of joy when her boss called her to report that ignition had been achieved, while Ma was in an airport waiting room. “I was jumping up and down.”
“We had some rocky times,” said Rep. Zoe Lofgren, a Bay Area Democrat who fought multiple efforts to defund the National Ignition Facility. “To see they have achieved ignition is fabulous. It is a profound breakthrough that brings an enticing promise that we could produce a nonpolluting, basically limitless source of energy.”
Whether that promise will ever be fulfilled is hotly debated among scientists.
“Useful energy production from miniature fusion explosions still faces enormous engineering challenges, and we don’t know if those challenges can be overcome,” said Ian Hutchinson, a professor of nuclear science and engineering at MIT.
For now, scientists will be focused on unlocking more practical and affordable ways to replicate the fusion reaction that powers the sun. In the sun’s core, the tremendous pressure drives hydrogen nuclei together. They combine to create helium and other light elements, converting some of the mass to energy.
This is such an efficient way to produce energy that it has allowed the sun to burn at a steady rate for many billions of years, long enough for life to appear and evolve on our sun-warmed planet roughly 93 million miles away.
Nuclear fusion is also what allows hydrogen bombs to deliver tremendously violent explosions. Such fusion bombs are far more powerful than the atomic bombs that employ nuclear fission, in which atoms are split rather than fused.
Using nuclear fusion for peaceful purposes has been a technological goal for decades. Experimental fusion reactors heat plasmas — free electrons and atomic nuclei — to temperatures exceeding 100 million degrees Celsius, hotter than the sun’s core.
The next step is to confine that hot plasma in a tiny space, where the atomic particles can potentially undergo a fusion reaction. That can be done in different ways, reflected in the varying business plans of energy start-ups hoping to eventually deploy fusion energy to the electric grid.
The history of fusion energy research is a tale of incremental milestones and recurring frustrations.
It has been a long and expensive endeavor largely funded by the U.S. government, as well as governments in other nations, with a long way still to go. It is a standard joke in the field that commercially available fusion energy is always 20 years (or some similar figure) away.
The National Ignition Facility was budgeted at $1 billion. It ended up costing about $3.5 billion by the time it was completed a decade ago, according to the lab’s website.
Innovators argue that Tuesday’s announcement validates all the resources that have been poured into chasing fusion energy.
“It is exactly the role of government to pursue science that could have enormous payoff and benefit the country and humanity that others won’t pursue,” said Josh Freed, leader of climate and energy at Third Way, a center-left think tank. “The examples of benefits from government investments in innovations that no one else was willing to finance are legion. We don’t know what will work, what won’t work, what we will discover unless we try.”
While the pursuit of fusion science was initially driven by concerns around the nuclear weapons stockpile, much of the focus has since shifted to energy amid the Biden administration’s aggressive climate aspirations. Several companies have emerged in recent years with the goal of building electricity plants powered by fusion.
“Fusion is the most disruptive energy source we can ever make,” said Dennis Whyte, director of the MIT Plasma Science & Fusion Center. “The fuel is inexhaustible. It is inherently safe and provides on-demand energy that is adaptable to our needs. On paper, it can supply our energy demands forever. Not many things look like that in the energy landscape.”
Whyte said more than $1 trillion is spent on energy in the United States annually, so an investment even of many billions of dollars in a technology that could prove transformational and position the country as a leader is, in his view, money well spent. He noted that China and other countries are eagerly pursuing their own programs, hoping for dominance in this area.
But the news drew mixed reactions from environmentalists, who noted that the technology is unlikely to come online soon enough to address the immediate dangers posed by global warming. Tom Cochran, the former head of the nuclear program at the Natural Resources Defense Council, argued the advance will be more useful for the nation’s nuclear weapons program.
“What irks me is the continued implication that this has some peaceful purpose,” he said.
Electricity providers are proceeding cautiously, but some are starting to prepare for the possibility of a future with fusion plants. Duke Energy, for example, contemplates the prospect in its most recent climate report, and it is among those on a committee guiding a company called General Fusion as it endeavors to build a fusion-fueled power plant.
Getting to an emissions-free grid, said Andrew Sowder, senior technical executive at the Electric Power Research Institute, “is a heavy lift for the existing technologies, even if we were to build more nuclear, wind and solar, carbon capture.”
“The one thing everyone can say is they would love to have another tool in the toolbox,” Sowder said. “Fusion checks all the boxes. It is not going to come overnight, and it is not going to come free. But we can’t just hope for it. If we don’t get started investing more into it now, it will never be ready.”
correction
An earlier version of this article incorrectly referred to the National Nuclear Security Administration as the National Nuclear Safety Administration. The article has been corrected.
