If you’ve been experimenting with artificial intelligence chatbots such as ChatGPT, you’ll likely be impressed by how quickly they come back with sophisticated answers.
That’s a facet of the large language models they are based on but also relies on a huge amount of computer processing grunt. There’s a good reason why computer chip maker Nvidia became the most valuable listed company in the world this year.
Its graphics processing units (GPUs) have been fine-tuned to perform AI tasks. Everyone wants its chips and is willing to pay up to US$25,000 for a single H100, Nvidia’s high-performance GPU.
Last month, Elon Musk’s company xAI turned on the Colossus Supercomputer in Memphis, Tennessee. Equipped with 100,000 Nvidia H100s, it is technically the world’s most powerful and expensive supercomputer.
But at full capacity, it will also use a vast amount of power. A single ChatGPT query uses nearly 10 times as much electricity as a Google search. As humans start collectively making billions of AI queries each day, that amounts to a massive drain on energy supply.
That’s why big tech companies are leading a new push in nuclear power. They know that renewable energy production won’t be enough to fuel the AI revolution they have kickstarted. Microsoft has done a deal to reactivate the Three Mile Island nuclear reactor, which partially melted down in 1979.
Amazon and Google have signed agreements to develop modular nuclear reactors, which have a smaller footprint than existing nuclear reactors in the US, so can be situated closer to main centres and the electricity grid.
The cash injection from the tech sector is accelerating the development of new types of fission reactors. But in my hometown Wellington, local start-up Open Star is making progress towards fusion, a different type of nuclear power that has none of the risks associated with Three Mile Island and other fission reactors.
Last month, Open Star created and confined plasma for the first time in its small test reactor nestled in a warehouse in the Ngauranga Gorge. Plasma is a super-hot cloud of ionised gas that, at extreme temperatures, fuses atoms, which can release part of their mass as energy. That’s the process that powers the sun.
It’s clean, and safe, but incredibly difficult to replicate in a fusion reactor. Top nuclear physicists and engineers have been trying to crack the holy grail of energy production for decades. The last time I covered Open Star in the Listener ‒ more than a year ago ‒ the company, led by founder physicist Ratu Mataira, had just raised $10 million and was about to build its test reactor.
Achieving “first plasma” is a small but key milestone on the way to producing a fusion reaction.
At the heart of Open Star’s reactor is a superconducting magnet held up inside the device using supporting beams. Eventually, the magnet will levitate in the reactor, confining the plasma around it. If a reaction can be sustained, in theory, it allows for perpetual clean energy generation.
“We made a plasma today, so for me, it is like Christmas,” said Dr Darren Garnier, director of plasma science at OpenStar Technologies.
“We’re a fusion company now, not just a magnet company, or someone drawing schematics with only hopes and dreams.”
Mataira sees Open Star’s expertise in superconducting magnets as giving New Zealand an edge in the fusion race, which is seen as the real moon shot of renewable energy – hugely complex, but with massive potential for humanity if it can be achieved.
Eventually, AI supercomputers dishing up recipes and providing digital assistants may be powered by fusion reactors designed in Wellington.
