by Energy Secretary Jennifer Granholm was to announce a “major scientific breakthrough” on Tuesday in the decades-long quest to harness fusion, the energy that powers the sun and stars.
For the first time, researchers at Lawrence Livermore National Laboratory in California have produced more energy than was used to ignite it in a fusion reaction, something called net energy gain, according to a government official and a scientist familiar with the research. Both spoke on the condition of anonymity as they were not authorized to discuss the breakthrough prior to the announcement.
Granholm would appear with the Livermore researchers at a morning event in Washington. The Department of Energy declined to provide details in advance. The news was first reported by the Financial Times.
Fusion proponents hope that one day it can produce virtually unlimited, carbon-free energy, replacing fossil fuels and other traditional energy sources. It’s still decades away from fusion to producing the energy that powers homes and businesses. But the researchers said it was still an important step.
“It’s almost like a starting weapon,” said Professor Dennis Whyte, director of the Center for Plasma Science and Fusion at the Massachusetts Institute of Technology and a leader in fusion research. “We should be moving towards making fusion energy systems usable to combat climate change and energy security.”
Net energy gain has been an elusive goal, as fusion takes place at high temperatures and pressures that are incredibly difficult to control.
Fusion works by pressing hydrogen atoms together with such force that they transform into helium, releasing enormous amounts of energy and heat. Unlike other nuclear reactions, it does not generate radioactive waste.
Billions of dollars and decades of work have been spent on fusion research with exciting results – for a fraction of a second. Previously, researchers at the National Ignition Facility, the part of Lawrence Livermore where success occurred, used 192 lasers and temperatures several times hotter than the center of the sun to create an extremely short fusion reaction.
Lasers focus enormous amounts of heat into a small metal can. The result is a superheated plasma environment where fusion can occur.
An announcement that net energy is gained in a fusion reaction would be important, said Riccardo Betti, professor and laser fusion expert at the University of Rochester. But he said he still has a long way to go before the result is sustainable electricity generation.
He likened this breakthrough to the first time people learned that refining and converting oil into gasoline and igniting it could cause an explosion.
“You still don’t have your engine and tires,” Betti said. “You can’t say you have a car.”
It’s the net gain of energy applied to the fusion reaction itself, not the total amount of power required to run the lasers and run the project. For fusion to be viable, it would need to generate significantly more power and for longer.
Controlling the physics of stars is incredibly difficult. That point has been difficult to reach, Whyte said, as the fuel has to be hotter than the center of the sun. Fuel doesn’t want to stay hot, it wants to leak out and cool down. It’s an incredible challenge to contain it, he said.
According to Jeremy Chittenden, a professor specializing in plasma physics at Imperial College London, the net energy gain isn’t a big surprise given the progress the California lab has already made.
“This doesn’t take away the fact that this is an important milestone,” he said.
Advancing fusion research requires enormous resources and effort. One approach turns hydrogen into plasma, an electrically charged gas that is then controlled by huge magnets. This method is being explored in France in a collaboration between 35 countries called the International Thermonuclear Experimental Reactor, as well as researchers at the Massachusetts Institute of Technology and a private company.
Teams working on these projects on two continents last year announced significant advances in the vital magnets needed for their work.
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Mathew Daly reported from Washington. Maddie Burakoff of New York, St. Louis and Jennifer McDermott of Providence, RI reported.
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