No, Fusion Energy Won’t Be ‘Limitless’

“It’s not a question I get very often,” says Michl Binderbauer, CEO of TAE Technologies, when asked about the economics of his company’s tokamak design. People are more likely to query how he plans to get plasma in his reactor heated to 1 billion degrees Celsius, up from the 75 million the company has demonstrated so far. But the questions are intertwined, he says.

That extreme temperature is required because TAE uses boron as fuel, alongside hydrogen, which Binderbauer thinks will ultimately simplify the fusion reactor and result in a power plant that’s cheaper to build. He puts the costs somewhere between fission and renewables—roughly where the Princeton modelers say it needs to be. He points out that while fusion plants will be expensive to build, the fuel will be extremely cheap. Plus, a lower risk of accidents and less high-level radioactive waste should mean a reprieve from expensive regulations that have driven up costs for fission plants.  

Bob Mumgaard, the CEO of Commonwealth Fusion Systems, an MIT spinoff, says he was happy to see the Princeton modeling, because he thinks their tokamak can smash those cost requirements. That claim principally rests in a superpowerful magnet the company hopes will allow it to operate tokamaks—and hence power plants—at smaller scale, saving money. CFS is building a scaled-down prototype of its fusion design in Massachusetts that will include most of the components required of a working plant. “You can actually go and see it and touch it and look at the machines,” he says. 

Nicholas Hawker, CEO of First Light Fusion, an inertial fusion company, published his own economic analysis for fusion power in 2020 and was surprised to find that the biggest drivers of cost were not in the fusion chamber and its unusual materials, but in the capacitors and turbines any power plant needs. 

Still, Hawker expects a slower ramp-up than some of his colleagues. “The first plants are going to break all the time,” he says, and the industry will require significant government support—just like the solar industry has over the past two decades. That’s why he thinks it’s a good thing that lots of governments and companies are trying out different approaches: It increases the chance that some technologies will survive. 

Schwartz agrees. “It would be weird if the universe only permits one form of fusion energy to exist,” he says. That diversity is important, he says, because otherwise the industry risks figuring out the science only to back itself into an uneconomical corner. Both nuclear fission and solar panels went through similar periods of experimentation earlier in their technological trajectories. Over time, both converged on single designs—photovoltaics and massive pressurized water reactors seen around the world—that were built all over the globe. 

For fusion, however, first things first: the science. It might not work anytime soon. Perhaps it will take another 30 years. But Ward, in spite of his caution about the limits of fusion on the grid, still thinks the research is already paying for itself, generating new advances in basic science and in the creation of new materials. “I still think it’s totally worth it,” he says.