“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 ask how it plans to heat the plasma in its reactor to 1 billion degrees Celsius, up from the 75 million the company has demonstrated so far. But the issues are related, he says.
This extreme temperature is necessary because TAE uses boron as a fuel, alongside hydrogen, which Binderbauer says will ultimately simplify the fusion reactor and result in a cheaper-to-build power plant. It puts the costs somewhere between fission and renewables, about where Princeton modellers say it needs to be. He points out that while fusion plants will be expensive to build, the fuel will be extremely cheap. Additionally, lower accident risk and less high-level radioactive waste should mean a reprieve from costly regulations that have driven up the costs of fission power plants.
Bob Mumgaard, the CEO of Commonwealth Fusion Systems, an MIT spin-off, says he was happy to see Princeton’s modeling because he thinks their tokamak can break those cost requirements. This claim is based primarily on a super-powerful magnet that the company hopes will allow it to operate tokamaks – and therefore power plants – on a 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 see it, touch it and look at the machines,” he says.
Nicholas Hawker, CEO of First Light Fusion, an inertial fusion company, posted his economic analysis of fusion energy in 2020 and was surprised to find that the main cost drivers were not in the melting chamber and its unusual materials, but in the capacitors and turbines that every power plant needs.
Still, Hawker expects a slower ramp-up than some of his colleagues. “Early plants are going to fail all the time,” he says, and the industry will need significant government support, just as the solar industry has done for the past two decades. That’s why he thinks it’s a good thing that many governments and companies are trying different approaches: it increases the chances that certain technologies will survive.
Schwartz agrees. “It would be weird if the universe only allowed one form of fusion energy to exist,” he says. This diversity is important, he says, because otherwise industry risks understanding science only to retreat into an uneconomic corner. Nuclear fission and solar panels went through similar periods of experimentation earlier in their technological trajectories. Over time, the two converged into unique designs – photovoltaics and huge pressurized water reactors seen around the world – which were built all over the world.
For fusion, however, first: science. It might not work anytime soon. It may take another 30 years. But Ward, despite his caution about the limits of grid fusion, still thinks the research is already paying off, generating new advances in basic science and in the creation of new materials. “I still think it’s really worth it,” he says.