Nuclear fusion has been a pipe dream for decades, but it may actually be on the verge of commercial viability


In the dense field of potential zero-emission solutions, nuclear fusion stands out for its scope and ambition. By successfully replicating the reaction that powers the sun, humanity could – in the words of Stephen Hawking – unlock an “endless supply of energy, free from pollution and global warming”. However, fusion development has progressed at a glacial pace for decades and breakthroughs have been intermittent at best.

That could be about to change. Thanks to extensive international collaboration and billions of dollars of public and private investment, scientists have recently achieved a series of significant advances in both the duration and power output possible from fusion reactions.

While nuclear fission – the process that powers conventional nuclear power plants – involves the splitting of atoms, fusion takes place when a pair of light atomic nuclei combine to form a single heavier one. When this happens, an immense amount of energy is released: four times more than fission, and nearly 4 million times greater than burning fossil fuels. From a safety point of view, nuclear fusion is practically impossible and only a small volume of relatively short-lived radioactive waste is produced.

The incredible promise of Fusion is being pursued by a consortium of global physicists supported by China, Russia, the United States and several European governments. With the funding taps opening, significant progress has recently been made in overcoming a litany of scientific challenges, including the enormous temperatures required to initiate a fusion reaction. At the core of the sun, atoms combine at about 10 million degrees Celsius; on Earth, where gravitational forces are much, much smaller, it takes at least 10 times as much heat.

As no known material can withstand contact with such scorching temperatures, scientists have developed different methods of confining the super hot plasma – a cloud of charged particles in which fusion occurs – to enable continuous energy production. . In California, the National Ignition Facility (NIF) is developing the use of high-powered lasers to compress fusion fuel into tiny space, while researchers in other parts of the world are prioritizing confinement via strong magnetic fields.

Promising progress

The Joint European Torus (JET) is a pioneer of the latter. Breaking its own world record for fusion energy, the UK-based JET laboratory recently managed to produce and sustain a relatively high level of thermal energy over a period of five seconds. Just under 60 megajoules (MJ) of energy was generated, just enough to boil a few dozen kettles, but it marked a significant step forward in the quest for sustainable fusion power.

“A five-second pulse and 59 MJ energy output may not sound like a lot, but it shows that we are able to achieve a sustained discharge that produces a high fusion yield,” says co-nuclear physicist Joelle Mailloux. – director of the JET research team. “We now have a plan to scale up operations in the future, with the aim of keeping production going for much more than a few seconds.”

However, huge hurdles remain for global fusion research. The record-breaking JET experiment used far more energy than it produced – the net energy gain from fusion has yet to be demonstrated anywhere – while the magnets used to hold the plasma warmed up too quickly for prolonged operation.

Nevertheless, progress is being made. Earlier this year, Chinese scientists managed to maintain a 17-minute fusion reaction, but with a fuel source that is not viable for large-scale power generation. Then there is the International Thermonuclear Experimental Reactor (ITER), the world’s most ambitious fusion project which, all goes well, will be operational by the middle of the decade.

Drawing on data from the soon to be decommissioned JET programme, the much larger ITER facility in the south of France is built from materials capable of withstanding much higher temperatures, allowing, in theory, fusion experiments to last long enough to produce more energy. that they consume. But that’s unlikely to happen before the late 2040s, experts say, and when it does, it’s unclear how quickly fusion power will become profitable.

“A wave of startups”

Another serious problem concerns the two forms of hydrogen, deuterium and tritium, used to power the fusion reaction of ITER. Deuterium can be derived in abundance from seawater, but tritium is exceptionally rare (only 20 kilograms are believed to exist worldwide). To overcome this deficit, techniques to “reproduce” tritium during fusion are being explored, Mailloux says, but again, this technology is likely decades away from realization.

Enter private enterprise. A wave of startups seeking alternative merger solutions has emerged in recent years, propelled by billions of dollars in venture capital investment. Among these is TAE Technologies, backed by Google and Chevron, a Californian company developing tritium-free fusion reactors.

By replacing the rare tritium-hydrogen isotope with non-radioactive hydrogen-boron, TAE chief executive Michl Binderbauer believes his team can sidestep fuel availability issues and achieve commercial power generation. from the early 2030s.

“Our machines are much more compact than other fusion reactors; a small town can be powered by a bus roughly the size of a few double-deckers,” says Binderbauer. “This means they will be easier to manufacture centrally, which will unlock economies of scale.”

On pricing, TAE is bullish – the cost per kWh will start halfway, Binderbauer argues, somewhere between nuclear fission at the high end and natural gas at the bottom. And as the cost of manufacturing complex components goes down, so does the price of energy.

However, not all members of the global scientific community are so confident. As an undergraduate physics student in the 1960s, Emeritus Professor Ian Lowe – a green energy expert at Griffith University in Australia – first heard that commercial fusion energy was in the less than 50 years old. More than half a century later, he fears this may still be the case.

“Yes, there have been some exciting developments, but at the end of the day, all potential fusion reactors are still in the research stage, and we need clean energy solutions now,” says Lowe. “We already have renewables that can generate cost-effective zero-carbon energy; scaling them up must be our priority.

This story is part The path to zero a special series exploring how businesses can lead the fight against climate change.


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