Nuclear Fusion

(Bloomberg) -- Nuclear fusion has been 20 years away for the last six decades, as physicists have long joked. But its allure never went away: the prospect of harnessing the fuel that powers the stars to produce clean, cheap and perhaps limitless electricity. Now climate change is making the quest more urgent than ever. That’s a big reason why a wave of startups backed by some of the world’s best minds and richest investors are focusing on what the late physicist Stephen Hawking called humankind’s most promising technology. 

The Situation 

Jeff Bezos, Bill Gates and Palantir Technologies Inc. co-founder Peter Thiel are just three of the billionaires investing in companies new to the field. They’re pursuing designs they hope can start generating power sooner than the 35-nation, $25 billion program known as ITER, the largest research project in history, whose collaborators have been laboring on a gigantic demonstration reactor in France since 2010. Its oft-delayed goal is to create power sustainably through fusion by 2035, though industrial-level electricity generation will have to wait for the next round of reactors. A pack of about two dozen startups includes Canada’s General Fusion, TAE Technologies outside Los Angeles and the U.K.’s First Light Fusion. All told, an estimated $1.1 billion has been raised for fusion-related startups. They’re hoping to use emerging technologies to speed reactor development: 3-D printing of individual parts lets engineers quickly create and test new versions, while artificial intelligence provides better and faster insights into how well those elements work. General Fusion and First Light Fusion are using a radically different design that focuses high energy on a target to induce atoms to fuse. China is a member of ITER but is working on its own reactor as well, with a goal of sustainable fusion by 2040.

The Background

Nuclear power comes in two flavors: fission, which unleashes energy by splitting atoms, and fusion, which merges them. Fission was the force behind the original atomic bombs and is used in nuclear plants around the world. Fusion is how the sun, which is made up mostly of hydrogen, produces energy. The crushing gravitational force at its core breaks down atoms into what’s known as plasma, an electrically charged gas in which sub-atomic particles can move about freely. Without the extreme gravity of the sun’s core, creating plasma on Earth requires temperatures far hotter than the sun — up to 150 million C (270 million F). Heat is generated through powerful magnets, by firing high-energy particles into the reactor and by zapping it with high-frequency waves. The highest temperature that’s been reached was above 100 million C, in China’s reactor in 2018. Atoms of two hydrogen isotopes are then squeezed together to overcome the force that normally makes atomic nuclei repel each other. When their nuclei strike, fusing to form helium, the neutrons released in the process are converted into energy. The problem for physicists is that so far, fusion reactors consume more energy than they create. The reactor being built by ITER uses a so-called tokamak design that dates back to the Soviet Union. In it, lasers and powerful electromagnets are arrayed around a super-cooled doughnut-shaped container to hold the super-heated plasma in place. The goal is to create conditions under which the process becomes efficient enough for fusion to be self-sustaining. Among fusion’s attractions: no nuclear waste and no dangerous radiation.

 The Argument

The surge of private capital reflects not only climate urgency, but a belief that the new technologies being developed in the push for fusion will have even if fusion itself needs yet another 20 years to pan out. Along with electricity for the grid, potential products include superconducting cables to transmit power more efficiently and high-powered magnets that could make MRIs better and cheaper. Meanwhile, skepticism about fusion has grown among at least some climate advocates. They argue that rapidly falling costs of solar and wind energy could make giant fusion reactors uneconomical by the time they’re ready to power up. As Elon Musk, the Tesla Inc. and Solar City Inc. co-founder, said, “We’ve got a giant thermonuclear reactor in the sky. It shows up every day very reliably. If you can generate energy from solar panels and store it with batteries, you can have it 24 hours a day.” On the other hand, ITER’s $25 billion budget looks like a modest side bet compared with the $3 trillion that United Nations scientists say the world should be spending every year to forestall the worst effects of climate change.

The Reference Shelf 

• ITER’s website and a page on “ Who Invented Fusion?”
• The Culham Centre for Fusion Energy’s page explaining the science of fusion. 
• The U.S. Department of Energy’s page on fusion sciences.
• A round-up in podcast form of “The Past, Present and Future of Fusion Energy.” 
• A Bloomberg News article on the Silicon Valley billionaires moving into fusion. 

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