Companies say they're closing in on nuclear fusion as an energy source. Will it work?
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This week, the world contemplates the possibility of a future without polluting fuel. At the United Nations climate conference in Dubai, climate envoy John Kerry plans to offer a strategy for commercial fusion energy. Scientists have hoped for generations to deliver the source of power that, in theory, could provide huge amounts of electricity without greenhouse gases. They've only recently demonstrated the theory. NPR's Geoff Brumfiel recently visited two commercial fusion companies to see how close they are to a breakthrough.
GEOFF BRUMFIEL, BYLINE: In a giant warehouse north of Seattle, I meet David Kirtley.
DAVID KIRTLEY: Hi.
BRUMFIEL: Hi.
KIRTLEY: David.
BRUMFIEL: This is the headquarters of Helion, a company that wants to put nuclear fusion on the power grid. One section of the building's been partitioned into offices, but on the other side is a vast manufacturing space with gleaming white floors.
Wow. This is maybe bigger than I expected.
KIRTLEY: So we moved the company up here about a year and a half ago - expanded our square footage quite a bit.
BRUMFIEL: Helion has more than 200 workers, shelves of gear, fancy fabrication machines, and in the middle of the floor are sets of aluminum rings that look like they could be the warp core of some sort of cool new starship. It's all about trying to create nuclear fusion. Fusion is the act of sticking light elements together. For example, if two hydrogen atoms get close enough, they fuse and make helium and a whole lot of energy.
KIRTLEY: We can generate electricity at, theoretically, much lower costs than we currently generate it now and do it without fossil fuels, without risk of nuclear weapons or any of those kinds of geopolitical issues, and do it quicker.
BRUMFIEL: As a matter of fact, fusion already has a proven track record of delivering reliable energy to Earth. Carolyn Kuranz is a nuclear physicist at the University of Michigan.
CAROLYN KURANZ: We experience fusion from the sun with the light and the heat that we receive every day.
BRUMFIEL: The sun is a giant fusion reactor that sustains all life on this planet. It's really efficient in fusion because of its size.
KURANZ: Basically, the sun weighs so much that it's able to squeeze these atoms together and fuse them.
BRUMFIEL: Its gravitational field crushes the atoms until they just can't resist sticking to one another. Here on Earth, it's a lot trickier. The cores of atoms repel each other, and the only way to overcome it is by heating the fusion fuel to extremely high temperatures.
KURANZ: It's really hard to do (laughter). Like, imagine putting the sun inside a gas tank or something.
BRUMFIEL: For more than half a century, scientists in government laboratories have been plodding along. Gradually, they've made progress. Last year, they finally used lasers to get a bit more energy out of a pellet of fusion fuel than they put in. But there's a long way to go from here to electricity.
KURANZ: It's a scientific facility, so it was never going to be some sort of like - a demonstration facility, which is kind of, like, one of the steps you need to do to be able to demonstrate you can have electricity.
BRUMFIEL: And even if future experiments can demonstrate electrical output, they're still decades away from actually changing the world. David Kirtley says when he was a physics student, he was frustrated by this slow scientific path.
KIRTLEY: The approaches for fusion that I was learning about in school weren't going to actually turn on and generate electrons on the grid in my lifetime at all.
BRUMFIEL: Helion was founded with a goal of building a machine that, right from the start, can generate power. Kirtley explains how it'll work. The machine uses electromagnets to form two doughnut rings of charged gas on opposite ends of a long tube. Then rapidly, it brings them together, heating and crushing them in an instant.
KIRTLEY: The faster we go, the more we can compress it, the more we can heat it, the more fusion we get out of it.
BRUMFIEL: So this is basically just a very elaborate magnetic hammer, it sounds like.
KIRTLEY: That's a good way to put it.
BRUMFIEL: Once the hammer smashes the atoms, they fuse, and the energy they release is recovered by the same magnets that did the crushing. It can be converted directly into electricity. It's a promising approach, but it's not the only one.
KIRTLEY: We have, I think, five fusion companies in this area now.
BRUMFIEL: In fact, just up the road is Zap Energy. Ben Levitt, Zap's VP for research, shows me their setup.
BEN LEVITT: Oh, OK. So, yeah, we can walk by. Its guts are all open, and we're working on it, but fuse is operational.
BRUMFIEL: Zap's machine looks like a long metal pipe. Inside, the company runs an electrical current through its fusion fuel, causing it to heat and compress all at once. Think of it as lightning in a bottle. Zap is working on multiple versions of its device, racing towards its goals. It's the sort of thing that Levitt says can only happen in the private sector.
LEVITT: There's no red tape, you know? We're properly funded for making bold decisions on engineering. That's the thesis of the private fusion company, is, like, if well capitalized, can you advance fusion science on a rapid industrial basis?
BRUMFIEL: These companies have seen a huge influx of funding in recent years. Helion raised half a billion dollars in its last round in 2021. Zap has backing from the likes of Chevron and Shell and Breakthrough Energy Ventures, a private venture capital firm started by Microsoft founder Bill Gates. Phil Larochelle is a partner at Breakthrough Energy. He says the business reason for investing in fusion - it's pretty simple. It's way more efficient than burning natural gas or oil, cheaper and cleaner.
PHIL LAROCHELLE: Fusion is the ultimate energy source. It's got a millionfold improvement in energy density over what we use now. And also, if we can get it to work, there's so much of the fuel that it's basically infinite, free, accessible to all and, if we do it right, carbon-free.
BRUMFIEL: He says the time is right for private industry to invest. The decades of slow and steady work by governments has built up the knowledge around fusion to a point where it's possible to make a giant leap forward.
LAROCHELLE: We are now just getting to the point where we're getting to the big payoff of about 50-plus years of research.
BRUMFIEL: But fusion is still a really tough problem. Unexpected effects like turbulence can ruin even the most beautiful experiments. Carlos Paz-Soldan is a physicist at Columbia University. He agrees that there's lots of potential in fusion right now.
CARLOS PAZ-SOLDAN: I definitely think the field was ready for investment.
BRUMFIEL: He's happy to see venture capital flowing into all kinds of different approaches - everything from lasers to magnets to Zap's bottled lightning.
PAZ-SOLDAN: Now, will any of them be successful? I think that's the bet that the venture capitalists are making. That's something we should all hope comes through, but it's TBD.
BRUMFIEL: The wait to find out if it works may not be very long. Back at Helion, David Kirtley points to another warehouse next to the one I'm visiting. The new machine they're assembling there is so top secret, he doesn't want to take me inside, but he says he thinks it'll be a game changer.
KIRTLEY: We're building Polaris, our seventh-generation system, that should show that we can make more electricity from fusion than we put into it for the first time.
BRUMFIEL: It's ambitious. I mean, 50, 60 years of trying and no one else has done it.
KIRTLEY: I think technology and physics have both evolved.
BRUMFIEL: The world has never needed fusion more than it does today, Kirtley says. He hopes his company will be the one that delivers.
Geoff Brumfiel, NPR News.
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