Fusion breakthrough could be climate, energy game-changer

Secretary of Energy Jennifer Granholm, centre, announces a major scientific breakthrough in fusion research that was made at a lab in California, during a news conference at the Department of Energy in Washington on Dec. 13, 2022.J. Scott Applewhite/The Associated Press

Scientists have reached a major milestone in the pursuit of nuclear fusion, a process that powers the stars and could one day provide a globally accessible long-term supply of carbon-free energy.

U.S. government officials said the breakthrough was achieved last week at the National Ignition Facility at Lawrence Livermore National Laboratory, the site of a long running effort to achieve fusion by blasting specially designed targets with powerful laser beams.

During a test on Dec. 5, the nuclear reactions triggered in a tiny target released about 1.5 more energy during the experiment than it received when it was struck with a powerful blast from the laser.

The result marks the first time that any such experiment has achieved a net energy gain – a critical threshold that is the primary goal of fusion research.

“This demonstrates that it can be done,” Energy Secretary Jennifer Granholm said at a news briefing in Washington, D.C., on Tuesday.

While the announcement does not immediately change the timeline for when fusion could be made practical, it adds to the growing sense of momentum in a field long regarded as offering a scientifically feasible but technically challenging solution to the world’s energy needs.

Thanks to public excitement and the urgent need to cut fossil fuel emissions that drive climate change, the development could indirectly boost prospects for several private companies that are working on quicker pathways to commercial fusion power.

But experts caution that public excitement around the Tuesday’s news should be tempered with the reality of how far scientists at the National Ignition Facility have to go in turning their approach to fusion into a useful energy source.

For example, last week’s experiment generated 3.15 Megajoules of energy from 2.05 Megajoules of input from the laser. Yet the laser draws about 300 Megajoules from the grid just to operate.

Now that a net energy gain has been achieved with the target, researchers said the next step is making the process more efficient and easily reproduced.

“A few decades of research on the underlying technologies could put us in a position to build a power plant,” said Kim Budil, director of the laboratory.

The facility was constructed in the late 1990s and the first tests conducted in 2009. After years of incremental progress, scientists reported last year that they were 70 per cent of the way to net energy gain and expressed optimism about reaching that goal.

Their approach uses the world’s highest energy laser to blast small BB-size targets consisting of isotopes of hydrogen packed inside a diamond shell. During a test, the laser beam is divided into several separate beams which converge on the target from multiple directions and rapidly compress it in time scales of about one billionth of a second.

At that point, the hydrogen isotopes – deuterium and tritium – are so squeezed that they are converted into helium, momentarily releasing energy in the process.

The process, known as inertial confinement, is one of two routes to fusion that have long been pursued by large government-funded megaprojects.

The other, called magnetic confinement, involves trapping a high temperature plasma in a powerful magnetic field until fusion reactions can take place. That is the strategy behind ITER, a giant demonstration reactor that is nearing completion in France and expected to begin operations in 2025.

Although magnetic confinement is considered further ahead along the path to energy generation, neither facility is designed to harness its output to provide electricity – only to achieve fusion consistently and lay a foundation for future work.

Elsewhere, companies in North American and Europe have been working on technologies that may offer shortcuts to commercial fusion.

Among them is Commonwealth Fusion Systems of Massachusetts, which is now building its first demonstration reactor that employs a more compact form of magnetic confinement that is also on track to be operating by 2025.

Vancouver-based General Fusion has a different reactor design that combines elements of both magnetic and inertial confinement. Its demonstration facility is set to be ready for testing by 2027.

“Having the underlying science is important, but if it doesn’t end on a path to a commercial power plant, it becomes a lot less interesting, at least to investors,” said Greg Twinney, chief executive of General Fusion.

High public excitement has become a regular feature of fusion announcements in recent years. This can be chalked up to the promise of an unlimited source of power that does not depend on fossil fuels but can operate continuously, unlike wind or solar energy.

Fusion is also regarded as less risky than conventional nuclear power, which is based on a different type of nuclear reaction called fission. Instead of undergoing a meltdown, a fusion reactor simply shuts down when it is not controlled. And while fusion does generate radiation is does not produce large quantities of radioactive waste from spent fuel, one of the big downsides of fission energy.

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