Harnessing the power of the sun

PAUL BUTLER, HOST: It’s Thursday the 22nd of December, 2022.

Glad to have you along for today’s edition of The World and Everything in It. Good morning, I’m Paul Butler.

MYRNA BROWN, HOST: And I’m Myrna Brown. First up on The World and Everything in It: clean energy.

The U.S. Department of Energy announced a breakthrough in fusion technology last week. For the first time ever, a fusion reaction produced more energy than it took to start it. Some scientists think fusion could be the next step toward cleaner and more sustainable energy. WORLD’s Mary Muncy has the story.

MARY MUNCY, REPORTER: In a lab in Livermore, California, physicists pointed lasers at a small, round capsule. They’d been doing this experiment for months—tweaking small things each time.

CASEY: My name is Daniel Thomas Casey, and I'm an experimental physicist working at the NIF here at Lawrence Livermore National Laboratory.

Casey was a part of a group of physicists trying to recreate the chemical process that happens in the sun on Earth.

CASEY: What we do is we take isotopes of hydrogen, and we effectively push them together. And in doing so that process releases energy, the isotopes combine together and create helium.

The theory is that in the sun, isotopes are constantly swirling and being pushed together and the energy that’s released when they’re pushed together is what makes our sun burn.

The problem is our sun burns hotter than nearly anything on Earth while creating immense gravitational pressure.

On earth, we can’t recreate that gravitational pressure. So instead we heat these isotopes up, say, about ten times hotter than the center of the sun.

CASEY: So basically, you've got this hollow capsule, you put a ton of energy into this can and it causes the capsule to crush and implode.

Livermore laboratory fired 192 lasers at a target about the size of a thumb. Inside that target is a BB sized capsule. The goal was to crush that BB down to the size of a human hair—forcing the isotopes together—otherwise known as a fusion reaction.

Fusion is actually not that difficult to accomplish. The hard part is creating more energy from the reaction than it took to start it.

CASEY: So we are in a race where we have to make enough fusion energy to outrun those losses. And last week, December 5, Monday, last week, about 1am, we won the race, we made more fusion energy in an experiment for the first time in the laboratory than laser energy we put on the target.

The breakthrough was a culmination of 60 years of research.

U.S. Energy Secretary Jennifer Granholm.

GRANHOLM: Simply put this one of the most impressive scientific feats of the 21st century [Applause]

The fusion reaction produced about 3.15 mega-joules of energy, compared to the 2.15 mega-joules of energy it took to produce it. In itself, that’s not that much energy. It might be enough to boil a pot of water. But the amount of power? That’s what’s interesting.

CASEY: At that moment, it was just for a fraction of a second, but it was more power than all of the sunlight on the surface of the earth.

Power is just energy as a function of time. The amount of energy produced in that fraction of a second was incredible for that amount of time.

But to make that energy useful, that reaction would have to be repeated multiple times a second.

Right now, we don’t have the technology to make it work, but scientists have plans.

ITER AD: Welcome to ITER, one of the world’s most ambitious scientific projects ever invented.

ITER is a joint project between 35 countries to create sustainable fusion energy. The project is a giant Tokamak.

The main component of a Tokamak is a donut-shaped chamber called a vacuum vessel.

An ITER employee explains.

TOKAMAK: The ITER Vacuum vessel is where we will inject the hydrogen gas and heat it to become a plasma so that we can create fusion energy at 150 million degrees Celsius.

The idea is that the plasma will act like the center of the sun and swirl isotopes around creating fusion energy. Then the tokamak will store this energy and turn it into electricity to power the world.

As you might expect, heating things hotter than the sun has some complications.

WARRICK: My name is Chris Warick I’m the head of communications for the atomic energy authority.

In a fusion tutorial, Warrick explained several major challenges to creating fusion energy. The first was the fusion reaction itself, but that’s been proven at least possible, if not yet sustainable.

Another challenge is that the plasma is extremely hot—again, hotter than the sun—and needs something to contain it. Warrick is talking about a particular tokamak named JET.

WARRICK: In the case of burning plasma, we require that to burn potentially continuously but certainly many hours at a time, and if we contrast that with what JET can do. Jet can only operate for 30 to 40 seconds, maybe a minute at most.

Another concern is that the fuel needed may not be as readily available as hoped and that we don’t have the technology to capture the energy once we create it.

The idea that fusion could power the world is still far off. But the breakthrough is a wonder.

Here’s Casey with Livermore labs again.

CASEY: In, you know, the early 1900s, the Wright Brothers showed that a, an airplane could carry people, you know, that airplane did not look a whole lot like the passenger jets of today. But at that moment, we knew what was possible.

Reporting for WORLD, I’m Mary Muncy.

WORLD Radio transcripts are created on a rush deadline. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of WORLD Radio programming is the audio record.