On Tuesday 13th December 2022, the U.S. Department of Energy and Lawrence Livermore National Laboratory announced that the National Ignition Facility (NIF) had achieved net energy gain in their fusion machine. In other words they initiated fusion reactions that generated more energy than the energy put in to start the process.
The news has been hailed as a breakthrough and received extensive media coverage, but critics point out that the energy released was tiny and that we are a long way from having any fusion electricity on the grid.
So why all the hype? Is it really such a big deal?
WASHINGTON, DC - DECEMBER 13: Scientists from the Lawrence Livermore National Laboratories (L-R) ... [+]
The dream of fusion
Fusion is the way the Sun and stars make energy—by the joining together of small particles (atomic nuclei) to make larger ones. Fusion energy on Earth would provide abundant, low-carbon, on-demand electricity to complement renewables, and could also be used to provide heat for industry, to generate hydrogen or for desalination, thereby tackling some of the hardest sectors to decarbonise. It would offer a long-term, clean energy solution, so it is very appealing.
Because it is the energy source of the stars, fusion requires extreme conditions in order to happen—such as temperatures of hundreds of millions of degrees—so it is very difficult to do on Earth. This is why the NIF breakthrough is such a feted achievement.
There are a number of different fusion approaches being investigated by laboratories or private companies. The mainstream government-funded approaches use either magnetic fields to trap hot, electrically-charged fuel away from the machine walls, or lasers fired at a tiny pellet of fuel to compress it to fusion conditions.
What is the “breakthrough”?
The fusion approach pursued at NIF is inertial confinement fusion, where a small pellet of fusion fuel is compressed to the high densities and temperatures required for fusion. To do this, NIF uses x-rays generated from 192 laser beams hitting a gold can the size of a pencil eraser and converging on a fuel pellet smaller than a peppercorn.
2.05 megajoules (MJ) of energy was delivered to the fuel pellet and 3.15MJ of energy was released in fusion reactions, giving an energy gain of 1.5 or 150%.
Naturally there is some scepticism. 3.15MJ is only a tiny amount of energy, enough to boil a few kettles. Additionally, the laser took several hundred megajoules to run, so if you take that into account they are nowhere near an “engineering” breakeven. We are still a long way from real fusion power to the grid. So is this really a significant breakthrough?
Yes.
What the NIF fusion result means
The industry has been working towards breakeven for decades. It's what they refer to as the "Kitty Hawk" moment or the "Wright Brothers" moment, comparing it with the first take-off of an aeroplane.
The reason that this result is so important—the achievement of net energy gain—is that it demonstrates that fusion power on Earth is possible in a power-plant context. It’s not just happening in the Sun or in a nuclear test; it can be made to happen in a controlled manner in a fusion device. With scientific viability proven, it opens up the pathway to commercial fusion development. It makes these big engineering challenges worth pursuing.
"This is the fundamental building block of an inertial fusion power scheme," said Dr Kim Budil, Director of Lawrence Livermore National Laboratory.
U.S. Secretary of Energy Jennifer M. Granholm said: "This demonstrates it can be done. It allows them to start working on the things that will enable fusion to be taken to commercial scale." She added: “Today’s announcement is a huge step forward to the President’s goal of achieving commercial fusion within a decade.”
This illustration provided by the National Ignition Facility at the Lawrence Livermore National ... [+]
U.K. Science Minister George Freeman said of the achievement: “This is a fantastic result that proves the exceptional potential of fusion power, and the National Ignition Facility team should be congratulated on their outstanding achievement. I’m proud that the BEIS-funded Central Laser Facility were also able to play a part in supporting the endeavour.
“Though there is still some way to go to deliver fusion power generation at scale, results like this one illustrate that there is a viable route to commercial fusion energy ahead, and the UK is in pole position to build on this work towards a clean energy future.”
Scott Hsu, Lead Fusion Coordinator at the U.S. Department of Energy, said: “This achievement will hopefully bring increased attention to the promise of fusion and the support needed to tackle the remaining scientific and technological challenges as quickly as possible.”
They may not be there yet, but this result will add to the already growing momentum in the industry. It will speed up development.
The growing fusion industry
I reported in July about the huge growth in the fusion energy industry. To date, over 30 private fusion companies have seen around $5bn of investment. The U.S. and U.K. governments in particular are increasingly supportive of fusion and are starting to facilitate greater cooperation between the national labs and the private fusion companies, such as the new U.S. milestone-based public-private partnership scheme ($50m) and the U.K. Fusion Industry Programme (£42.1m).
The number of private fusion companies and when they were founded, from the report "the Global ... [+]
Private companies are using newer technologies and sometimes novel approaches to develop a commercial fusion solution. In proving the fundamental science, the NIF result benefits the whole industry, although it’s especially exciting for the inertial fusion community.
“This is the role of the national labs—to prove that the science works. It’s now the job of the private companies to take that and turn it into something commercially relevant,” said Ross Morgan, Commercial Director of Tokamak Energy. “We can do that quicker by using private money and taking more risks.”
What’s next?
There are a number of engineering challenges that lie ahead, including increasing laser efficiency and repetition rate, developing systems to harness the energy of the neutrons produced and breed tritium, and working on improved materials for power-plant longevity. Public laboratories, like Culham Centre for Fusion Energy in the UK, are already setting up facilities to tackle these challenges, often in collaboration with the private sector. Many private companies are working on power plant designs, often developing approaches that circumvent the most difficult of the challenges.
Nick Hawker, CEO of First Light Fusion, wrote a good Twitter thread explaining the importance of the NIF result to his company and commenting on the progression to a power station.
“There is a clear path to a power plant here,” he said. “The NIF laser is far too expensive. Other approaches still need cost reductions but are closer. The Dipole Concept from the Central Laser Facility in the UK is one example.
“It is also very clear what is needed for cost-competitive power production. For the laser approach, the driver and target cost needs to fall, and the survivability of the target chamber needs to be improved.”
Hawker was delighted with the result. “For First Light Fusion this is a huge derisking. The core physics of our approach is exactly the same…. This is a holy grail moment. I’m buzzing,” he said.
While there is still a lot of work to do before we see fusion power plants generating electricity for the grid, this is a huge milestone and indeed a breakthrough result for the industry. It is a historic achievement that deserves to be celebrated.
