LIVERMORE, Calif., July 9 — The morning light slants through the scrub oaks east of San Francisco, past the security gates of Lawrence Livermore National Laboratory. Inside, in a cavernous building, 192 laser beams are being readied to fire on a pellet of fuel smaller than a peppercorn. The goal, on this July morning, is to recreate the power of the Sun.
On December 5, 2022, they did it. For the first time in a laboratory, scientists here achieved what they call ignition: a net energy gain from nuclear fusion.
The experiment produced 3.15 megajoules of energy from 2.05 megajoules of input — a gain of about 1.5 times. The U.S. Department of Energy confirmed the milestone on December 13 of that year. It was a moment that had been decades in the making, and it changed the conversation around fusion energy overnight.
The process itself is elegant and violent. Fusion is the reaction that powers the Sun: atomic nuclei combine to release enormous energy.
Here on Earth, scientists use isotopes of hydrogen — deuterium and tritium — and subject them to temperatures over 100 million degrees Celsius and immense pressure. At the National Ignition Facility, or NIF, that pressure comes from those 192 laser beams compressing a tiny pellet of fuel. Unlike nuclear fission, which splits atoms and leaves behind long-lived radioactive waste, fusion produces no such waste.
There is no risk of a meltdown. That December breakthrough was a proof of concept, not a power plant. The challenges that remain are enormous.
Scaling up the process, reducing costs, and sustaining reactions continuously — all of this is still ahead. Scientists on the ground here describe the work as painstaking, incremental.
One successful shot does not a commercial reactor make.
The long road to a trillion-dollar market
The global fusion energy market is projected to reach $1.5 trillion by 2050, according to a 2022 report from the Fusion Industry Association. That projection is driving a surge of investment. Total global investment in fusion startups exceeded $5 billion by 2023, the association reported.
Private companies are now racing to turn the science into something that can plug into the grid. Commonwealth Fusion Systems, founded in 2018, is one of the most prominent.
The company is aiming for a commercial reactor by 2035. TAE Technologies, founded in 1998, has been at it even longer. Both are pursuing different technical approaches, but the destination is the same: a fusion power plant that can deliver electricity reliably and affordably.
Then there is ITER. The international project in France, a collaboration involving 35 countries, is building a tokamak reactor — a donut-shaped machine that uses magnetic fields to contain the fusion reaction.
ITER is expected to begin operations in 2025 and achieve full fusion power by 2035. It is the largest and most expensive fusion experiment ever built, and its timeline has slipped more than once. But when it works, it will be the first fusion reactor to produce more power than it consumes, sustained over long periods.
What ignition means
For the scientists at Livermore, the December 2022 shot was the culmination of years of meticulous work. The facility itself is a marvel of engineering: 192 laser beams must be aimed with microscopic precision at a target the size of a BB. The energy delivered is immense, but fleeting.
The reaction lasts only a fraction of a second. The 1.5 times gain is modest, but it is real.
It proved that fusion can produce more energy than it consumes, a threshold that had eluded researchers for decades. The scene inside the control room that December evening, by all accounts, was one of disbelief and elation. By nightfall, the news was spreading through the global physics community.
But the path from that single shot to a working power plant is long. The lasers at NIF were designed for weapons research, not electricity generation.
They fire once a day at most. A commercial reactor would need to produce pulses many times per second, reliably and cheaply. The materials that line the reaction chamber must withstand repeated blasts of neutrons and heat.
The engineering problems are as formidable as the physics ones.
What to watch next
The next big milestones are in France and in the private sector. ITER’s first operations in 2025 will be closely watched. If the tokamak can sustain a fusion reaction for minutes at a time, it will mark a major step forward.
Commonwealth Fusion Systems, meanwhile, is building its own demonstration device, aiming for net energy by the mid-2030s. The U.S. Department of Energy has also launched a program to fund fusion pilot plants, with the goal of having a design ready by the 2030s.
The competition is global: China, the United Kingdom, and Japan all have active fusion programs. For now, the work continues at Livermore. The lasers are firing.
The data is being analyzed. The scientists here know better than anyone that fusion energy is still decades away.
But for the first time, they also know it is possible.
