US scientists have performed the first-ever nuclear fusion experiment to achieve a net energy gain, paving the way for a “clean source of energy that could revolutionize the world”.
At a historic press conference at Lawrence Livermore National Laboratory in California, officials revealed that the successful fusion experiment took place last week.
As It Happened: An ‘Incredible’ Scientific Breakthrough Could Create Unlimited Energy
It was the result of “60 years of worldwide research, development, engineering and experimentation”, which could eventually become the backbone of commercial power generation.
Such an outcome would boost the global transition to renewable energy, helping to tackle climate change.
US Energy Secretary Jennifer Granholm said the breakthrough “will go down in the history books”.
“This is one of the most impressive scientific feats of the 21st century,” she added.
How was the experiment conducted?
The experiment involved 192 high-powered laser beams fired at a capsule containing the elements deuterium and tritium, heating it to a temperature of over three million degrees centigrade – thus briefly simulating the conditions of a star.
Dr Marvin Adams said it had been done “hundreds of times before” but never succeeded in producing more energy than it consumed.
“For the first time, they designed this experiment so that the fusion fuel would stay hot enough, dense enough, and round enough long enough to ignite and produce more energy than the lasers could. had filed,” he said.
“About two megajoules in, about three megajoules out – a gain of 1.5, energy production took less time than it takes light to travel an inch.”
It was, as he joked, “a bit fast.”
While the target was smaller than a pea, the lasers – part of the so-called NIF system – are powerful enough to deliver more energy than the entire electrical grid that sustains all of the United States.
Chief engineer Jean-Michel Di Nicola said it was “the size of three football pitches and delivers an energy of over two million joules with a peak output of 500 trillion watts”.
“For a very short period of time, a few billionths of a second, it overtakes the entire American power grid,” he said.
The NIF system includes 192 lasers
How long before the process can create usable energy?
The question on everyone’s lips after the press conference was how long it would take before the process could be used to create energy that we can actually use.
Dr Kim Budil, director of the Lawrence Livermore National Laboratory, admitted that it would “probably take decades”.
President Joe Biden has said he hopes a commercial fusion reactor will be in place within 10 years, and officials have acknowledged the private sector should play an important role in accelerating the move of experiments to the lab to commercial electricity generation.
Other nuclear fusion projects will also have a role to play – and the California scientists cited the work of a team from Oxfordshire, who earlier this year used their JET machine to generate approximately 11 megawatts of power.
This was far more than was generated in the NIF experiment, but – importantly – did not yield a net energy gain.
An important scientific step – but lasers require enormous power
As Dr. Marv Adams held the cylindrical target containing the “peppercorn” sized fusion fuel pellet, he confirmed that they had achieved the “ignition” of a fusion reaction.
He also revealed that the scientists put about 2MJ of energy into their fusion reaction and took out about 3MJ.
This is proof of the “energy gain” referred to in this ad.
This is the important scientific step: proving that a fusion reaction itself can generate more energy than you put in.
But they had to use 300 MJ of electricity to power their lasers.
So from a power generation perspective, they still have to put 99% more power into the machine as a whole as they go out.
Professor Gianluca Gregori of the University of Oxford, an expert in the types of lasers used in the lab, pointed out that the amount of energy produced was less than what is needed to power a wall socket.
“Although it is not yet an economically viable power station, the path for the future is much clearer,” he added.
Jeremy Chittenden, professor of plasma physics at Imperial College London, scientists “will have to find a way to reproduce the same effect much more frequently and at a lower cost”.
If they did, it would be a huge boost for the global push towards renewable energy.
