In August last year the control room at General Atomics had something to celebrate. A room full of scientists stood by their computers, took cell phone photos and cheered as their nuclear reactor generated “plasma shot” number 200,000.
Each plasma shot is an experimental fusion of hydrogen atoms you smash together to generate the heat that’s needed to produce energy.
“With fusion what we’re going to do is we take two particles, and if you smash them together hard enough, they release net energy,” said David Pace, deputy director of the fusion facility, run by General Atomics. “And that’s what we do. We want to smash together a lot of particles and make a lot of energy.”
Nuclear fusion is what happens on the sun. And the quest to “put the sun in a bottle” and provide fusion energy on earth has been going on since World War II.
The process leaves behind helium and clean energy, and none of that long-lasting nuclear waste that has bedeviled its power generating cousin, the nuclear fission power plant.
Richard Buttery is the director of what they call the DIII-D fusion reactor at General Atomics, which is funded by the department of energy. He said the promise of exploiting fusion on earth is a virtually limitless supply of energy.
“Because the fuel we have is abundant around the world. Deuterium. That’s one type of hydrogen that we use. You just extract that from seawater,” Buttery said. “The other fuel we want to use, lithium, is something you can pull out of the ground. It’s common and it’s in your cell phone batteries. And the amount you need to do a lot of energy is very small.”
The pursuit of fusion energy has been going on so long a lot of the testing infrastructure is pretty old school. The fusion reactor at General Atomics is called a tokamak, a technology first developed by the Russians that has been around since the 1960s.
It's a donut-shaped oven that conducts the intense heat needed for fusion. Powerful magnets are used to control the energy.
But with all the progress that’s been made over the years, we still don’t have the technology to contain and release fusion energy so it can boil water, run a turbine and generate power.
“We have a piece of science that we understand really, really well. But now we have to fold it into a physical device that takes you to the next step, that gets you close to producing electricity. And it’s really this integration and this full system approach that is just an incredibly challenging problem,” Pace said.
He said the industry still needs more research and development. The development of materials like the steel that go inside the reactor, that doesn’t erode unexpectedly or emit particles that are important to fusion.
Finding a way in the creation of ITER
A possible answer to this challenging problem is taking shape in France, an international project called ITER, Latin for “the way.”
It is a tokamak-powered facility that will be the closest thing the world has seen to a fusion power plant. Its goal is to get fusion to continue in the reactor under its own heat and power, not relying on the kind of imported heat needed for a brief plasma shot.
“We’re putting energy in to make it really hot,” Pace said. “Once it starts fusing the energy from the fusion keeps it hot enough that it keeps on fusing. Then we can turn off our heating and it’s what we call burning. Keeping itself at fusion temperatures and we can focus on extracting energy from it.”
Buttery says ITER’s goal is to produce ten times the fusion energy it gets from an outside heating source. This year General Atomics will ship ITER a magnet to contain its superhot ball of gas. And this won’t be any old magnet.
“This is a magnet that is so powerful that it could lift an aircraft carrier out of the water,” Buttery said.
Scientific work on fusion energy has gone on for so long you have to forgive people for casting doubt when they hear someone say we’re almost there.
Innovation and public policy professor David Victor co-directs UC San Diego’s energy decarbonization initiative. He said the old joke about fusion is that it’s the great energy source of the future and it always will be.
Even so, Victor said that recent progress toward the goal is no joke.
“There are a lot of improvements in technology that make several different strategies for fusion energy at least seem a lot more plausible than they did even five or ten years ago,” he said. “New kinds of lasers. In particular, new kinds of magnets, really, really powerful magnets that can contain a fusion plasma.”
But he cautions us to know every new energy source has uncertainties. And as we consider fusion, don't forget the potential for wind and solar. Even nuclear fission may have a future if the industry can build small modular units.
Meanwhile, Buttery said private sector investment in fusion in the U.S. has increased hugely, from venture capitalists to philanthropic groups.
“At the government level, the United States is investing strongly in fusion and so are our competitors. China is actually outspending the United States by a factor of two, in this government funding,” he said.
Buttery adds that with increased investment, people in the fusion field believe we will have fusion power plants sometime in the 2030s. If that does happen, the question of whether you can draw power from one of them may depend on where you live.
