Scientists hail nuclear fusion breakthrough but caution that climate change remains a crisis

The U.S. Department of Energy is set to announce Tuesday that researchers have produced a nuclear fusion reaction that creates a net energy gain, an important breakthrough in the search for a clean, affordable and potentially unlimited source of energy.

According to the Financial Times, which first reported the news on Sunday, the Lawrence Livermore National Laboratory, a federal research facility in Livermore, Calif., achieved net energy gain in an experiment during the last two weeks. The lab uses a process called inertial confinement fusion, in which a pellet of hydrogen plasma is bombarded by the world’s biggest laser. The process is highly energy-intensive, but in recent experiments it produced 120% as much energy as it consumed.

Scientists expressed excitement about the development, which several countries have pursued since the 1950s and have invested billions of dollars researching.

“There is going to be great pride that this is something that happened in the United States,” David Edelman, who leads policy and global affairs at TAE, a large private fusion energy company, told the Washington Post. “This is a very important milestone on the road toward fusion energy.”

“Scientifically, this is the first time that they showed that this is possible,” Gianluca Sarri, a physicist at Queen’s University Belfast in Northern Ireland, told New Scientist. “From theory, they knew that it should happen, but it was never seen in real life experimentally.”

The theoretical benefits of fusion reactions are enormous, as they create no conventional air pollution or planet-warming carbon dioxide. And unlike traditional nuclear reactors, which split atoms through a much less powerful process known as fission, fusion does not create long-lasting radioactive waste.

“The importance of this news cannot be overstated,” Leah Stokes, an environmental policy expert at the University of California, Santa Barbara, wrote on Twitter.

Yet applying the technology at commercial scale will be more difficult than performing a laboratory experiment, experts say.

“While we don’t have details yet, this could be an important step because fusion has potential as low-carbon generation with much less radioactive pollution than from conventional nuclear energy,” Matthew McKinzie, a nuclear physicist with the Natural Resources Defense Council, told Yahoo News in an email. “But we shouldn’t kid ourselves: Fusion as a source of electricity is a really, really hard problem, and it’s not yet clear how much of a breakthrough this is. One thing I am certain of is that we have to apply all the ready technology that we have today to the climate problem. We cannot wait decades for a source of power that isn’t yet proven to work.”

Even boosters of nuclear fusion admit that many questions remain unanswered and that it could take decades before the breakthrough can be used to provide electricity to the public. Nonetheless, investors are already beginning to flock to nuclear energy company stocks in response.

“The U.S. energy grid would need a significant redesign for fusion power plants to become common,” the Washington Post reported this summer. “The price of providing fusion power is still too high to be feasible.”

“We’re at a very exciting place,” Dennis Whyte, director of MIT’s Plasma Science and Fusion Center, told the newspaper at that time. “But we also have to be realistic in the sense that it’s still very hard.”

On Monday, some scientists voiced skepticism about the announcement, suggesting that it may be overhyped by a credulous media. Peter Gleick, the climatologist who founded the Pacific Institute, noted that the cost of fusion is currently dramatically higher than clean alternatives such as wind and solar.

Chanda Prescod-Weinstein, a physicist at the University of New Hampshire, pointed out that the process used by the DOE requires tritium, a rare and radioactive isotope of hydrogen.

“It may yet yield important information that is ultimately transformative. We don’t know yet,” she wrote. “Being able to do this once a day with a laser does not at all mean that this mechanism will scale! Really!”