U.S. Department of Energy scientists at the Lawrence Livermore National Laboratory (LLNL) in California have made a “major scientific breakthrough” in the field of nuclear fusion, according to a press release published today.

On December 5, researchers in the National Ignition Facility (NIF) – the lab’s $3.5 billion laser complex – conducted the first-ever controlled fusion reaction to successfully produce more energy than was used to create it.

Nuclear fusion is an artificial process where two atoms are forced together into one, thereby releasing an enormous amount of energy. It is the same process that powers stars like our Sun, and one that researchers have long sought to replicate on Earth in order to generate clean, sustainable energy. The historic achievement represents a “milestone” for the future of clean energy.

“Scientists have struggled to show that fusion can release more energy than is put in since the 1950s,” plasma physicist Dr. Arthur Turrell told the Financial Times, “and the researchers at Lawrence Livermore seem to have finally and absolutely smashed this decades-old goal.”

In the experiment last week, the NIF team used the world’s largest laser to wipe out a small pellet of hydrogen. The fusion reactor generated an energy output of 3.15 megajoules from an input of only 2.05 megajoules.

The breakthrough may very well have major implications for tackling the climate crisis. If scientists, engineers, policymakers, and business executives are able to come together to scale up and commercialize the technology, it could eventually provide an entirely new source of clean energy. However, there is still an immense amount of work to be done before it is possible to leverage nuclear fusion as a viable means of generating energy on a large scale.