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Why Widespread Fusion Energy Is Taking So Damn Long

The most powerful experimental fusion reactor is under budget and a decade behind schedule.
X-ray Sun. Photo: NASA/Wikimedia Commons

The dream of fusion energy hit a roadblock on Monday after it was revealed that it would take at least another decade and 4 billion euros for an international coalition to get its experimental reactor working.

That means the International Thermonuclear Experimental Reactor (ITER) in France won't see its first test until 2025 and full fusion reactions until at least 2035, according to documents leaked to French newspaper Les Echos.


ITER, a joint project between Europe, China, South Korea, India, Japan, Russia, and the United States, confirmed to Motherboard that 2025 and 2035 "are the most likely dates based on current discussion," although neither has been officially declared. An ITER spokesperson said an official announcement concerning the project schedule will be made in June.

Previous estimates, which ITER chief Bernard Bigot has called "totally unrealistic," aimed for "first plasma" tests by 2020 and full fusion by 2023.

It's no surprise that the project won't be completed anytime soon. Fusion isn't easy to achieve— at least, efficiently enough to make it a feasible replacement for fossil fuels. The ITER core will reach 150 million degrees Celsius, according to ITER, which is ten times hotter than the core of the sun. The process will fuse hydrogen atoms together to create helium, releasing a tremendous amount of energy in the process, which will be contained by a powerful magnetic field.

If commercialized, the benefits would be tremendous: plentiful power without carbon emissions or long-lived nuclear waste, all running on deuterium and tritium, which can be found in water and lithium, respectively.

"Fusion is so complicated"

The long-running joke in the field is that fusion is "always 30 years away." But let's say the most recent dates are realistic. Everything goes according to plan, and the first tests start in 2025 and ITER proves the technology is viable by 2035. What happens next?


Dennis Whyte, director of MIT's Plasma Science and Fusion Center, pointed out the long gap between a successful test and a working fusion power plant.

"Fusion is so complicated," Whyte said. "We know most of the science, but understanding what it takes to make commercially viable electricity is something that is hard to extrapolate."

When completed, ITER is expected to create 10 times the energy that is required to produce and heat its plasma. But fusion power plants will have to be at least five times more powerful, he said.

The current plan is to build a demo device that is even larger than the ITER tokamak, which will stretch nearly 80 feet across and weigh 23,000 tons, around 15 years after ITER achieves fusion. That would be in 2050. After that, a prototype would be built, which would serve as a model for other organizations looking to build their own fusion reactors.

That means we probably wouldn't see a power plant capable of providing energy to the grid until after the middle of the century—and that is if the research continues on schedule.

Concept image of ITER tokamak machine with plasma. Image © ITER Organization

Simply building an efficient fusion reactor isn't enough. We also have to figure out how to integrate fusion power into the global economy without destabilizing energy markets, Whyte said. And if the power plants are too expensive, poorer nations could be left behind.

"If you come up with an energy source that only developed countries can use, you haven't solved the problem," he said.


These are complex political and economic questions with no easy answers. There are also technical challenges to integrating fusion technology. Planes, ships, and most cars run on gasoline. Seeing as Mr. Fusion from the Back to the Future movies doesn't exist, we would have to convert vehicles to run on electric power or use fusion reactors to create hydrogen fuel and gasoline.

Whyte said he was certain that we would see fusion power by the end of the century. But with the threat of climate change, that just isn't fast enough, he said. He thinks fusion power could become a reality earlier than 2050 if the world takes a more aggressive approach to research, and would like to see more fusion projects funded so we don't have all our eggs in one very expensive basket.

"ITER is an invaluable science experiment," he said. "But we need parallel programs to simultaneously develop technologies."

That includes his own ARC reactor, which is designed to be half the size of ITER, but produce a similar amount of power thanks to new superconductors that create a stronger magnetic field. Both Amazon CEO Jeff Bezos and Microsoft co-founder Paul Allen have also invested in fusion research with companies called General Fusion and Tri Alpha, respectively.

New materials and technologies, such as 3D printing, have made Whyte more confident that commercially viable fusion energy will become a reality. He just wants bolder governments and businesses to pursue it.

"I think we need to start taking more risks," he said, "instead of waiting for the perfect solution 50 years from now."