Fusion energy 'breakthrough' revealed by U.S. scientists

U.S. Energy Secretary Jennifer Granholm announced a "major scientific breakthrough" on Tuesday in the decades-long quest to harness fusion, the energy that powers the sun and stars.

Officials say the achievement could be game-changer for climate, energy

In this 2012 image provided by Lawrence Livermore National Laboratory, a technician reviews an optic inside the preamplifier support structure, in Livermore, Calif. U.S. Energy Secretary Jennifer Granholm announced a 'major scientific breakthrough' on Tuesday in the decades-long quest to harness fusion. (Damien Jemison/Lawrence Livermore National Laboratory/The Associated Press)

Scientists announced Tuesday that they have for the first time produced more energy in a fusion reaction than was used to ignite it — a major breakthrough in the decades-long quest to harness the process that powers the sun.

Researchers at the Lawrence Livermore National Laboratory in California achieved the result, which is called net energy gain, the U.S. Energy Department said. Net energy gain has been an elusive goal because fusion happens at such high temperatures and pressures that it is incredibly difficult to control.

The breakthrough will pave the way for advancements in national defence and the future of clean power, Energy Secretary Jennifer Granholm and other officials said.

"Ignition allows us to replicate for the first time certain conditions that are found only in the stars and the sun," Granholm told a news conference in Washington, D.C. "This milestone moves us one significant step closer to the possibility of zero-carbon abundant fusion energy powering our society."

Fusion ignition is "one of the most impressive scientific feats of the 21st century," Granholm said, adding that the breakthrough "will go down in the history books."

Kim Budil, director of the Lawrence Livermore National Laboratory, reacts while answering questions during a U.S. Department of Energy news conference to announce that scientists at the lab have made a breakthrough on fusion energy, the process that powers the sun and stars that one day could provide a cheap source of clean electricity in Washington, D.C., on Tuesday. (Mary F. Calvert/Reuters)

Appearing with Granholm, White House science adviser Arati Prabhakar called the fusion ignition "a tremendous example of what perseverance really can achieve" and "an engineering marvel beyond belief."

Proponents of fusion hope that it could one day offer nearly limitless, carbon-free energy and displace fossil fuels and other traditional energy sources. Producing energy that powers homes and businesses from fusion is still decades away, but researchers said the announcement marked a significant advance nonetheless.

Tackling climate change

"It's almost like it's a starting gun going off," said professor Dennis Whyte, director of the Plasma Science and Fusion Center at the Massachusetts Institute of Technology and a leader in fusion research. "We should be pushing towards making fusion energy systems available to tackle climate change and energy security."

Kim Budil, director of the Lawrence Livermore lab, said there are "very significant hurdles" to commercial use of fusion technology, but advances in recent years mean the technology is likely to be widely used in "a few decades" rather than 50 or 60 years, as previously expected.

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Fusion works by pressing hydrogen atoms into each other with such force that they combine into helium, releasing enormous amounts of energy and heat. Unlike other nuclear reactions, it doesn't create radioactive waste.

U.S. President Joe Biden called the breakthrough a good example of the need to continue to invest in research and development. "Look what's going on from the Department of Energy on the nuclear front. There's a lot of good news on the horizon," he said at the White House.

Technicians use a service system lift to access the target chamber interior for inspection and maintenance at the National Ignition Facility, a laser-based inertial confinement fusion research device, at Lawrence Livermore National Laboratory federal research facility in Livermore, Calif., in 2008. (Philip Saltonstall/Lawrence Livermore National Laboratory/Handout/Reuters)

Billions of dollars and decades of work have gone into fusion research that has produced exhilarating results — for fractions of a second. Previously, researchers at the National Ignition Facility, the division of Lawrence Livermore where the success took place, used 192 lasers and temperatures multiple times hotter than the centre of the sun to create an extremely brief fusion reaction.

The lasers focus an enormous amount of heat on a small metal can. The result is a superheated plasma environment where fusion may occur.

Long road ahead

Riccardo Betti, a professor at the University of Rochester and expert in laser fusion, said there's a long road ahead before the net energy gain leads to sustainable electricity.

He likened the breakthrough to when humans first learned that refining oil into gasoline and igniting it could produce an explosion.

"You still don't have the engine, and you still don't have the tires," Betti said. "You can't say that you have a car."

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The net energy gain achievement applied to the fusion reaction itself, not the total amount of power it took to operate the lasers and run the project. For fusion to be viable, it will need to produce significantly more power and for longer.

It is incredibly difficult to control the physics of stars. Whyte, of the Plasma Science and Fusion Center, said the fuel has to be hotter than the centre of the sun. The fuel does not want to stay hot; it wants to leak out and get cold. Containing it is a challenge, he said.

The achievement of net energy gain isn't a huge surprise from the California lab because of the progress it had already made, according to Jeremy Chittenden, a professor at Imperial College London who specializes in plasma physics.

But, he said, "that doesn't take away from the fact that this is a significant milestone."

One approach to fusion turns hydrogen into plasma, an electrically charged gas, which is then controlled by humongous magnets. This method is being explored in France in a collaboration among 35 countries called the International Thermonuclear Experimental Reactor, as well as by researchers at the Massachusetts Institute of Technology and a private company.

Last year the teams working on those projects on two continents announced significant advancements in the vital magnets needed for their work.


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