Zap Energy, a fusion energy startup working on a low-cost path to producing electricity commercially, said last week that it had taken an important step to test a system that its researchers believe will eventually produce more electricity than it consumes. .
That point is seen as a milestone in solving the global energy challenge while moving away from fossil fuels. An emerging global industry made up of nearly three dozen start-ups and heavily funded government development projects pursues a variety of concepts. Seattle-based Zap Energy stands out because its approach, if it works, would be simpler and cheaper than what other companies are doing.
Today’s nuclear power plants are based on fission, which captures the energy released by the splitting of atoms. In addition to the intense heat, byproducts of the process include waste that remains radioactive for centuries. Nuclear fusion, on the other hand, replicates the process that takes place inside the sun, where gravitational forces fuse hydrogen atoms into helium.
For more than half a century, physicists have pursued the vision of commercial power plants based on a controlled fusion reaction, essentially bottling the sun’s power. Such a power plant would produce many times more electricity than it consumes, and without the radioactive byproducts. But none of the research projects have come close to the goal. Still, as fears of climate change mount, there is growing interest in the technology.
“We think it’s critical that fusion become part of our energy mix,” said Benj Conway, president of Zap Energy.
While many competing efforts use powerful magnets or bursts of laser light to compress a plasma in order to start a fusion reaction, Zap is following an approach pioneered by physicists at the University of Washington and Lawrence Livermore National Laboratory.
It is based on a shaped plasma gas, a cloud of energized particles often described as a fourth state of matter, that is compressed by a magnetic field generated by an electric current as it flows through a tube. empty two meters. The technique is known as “cut-flow Z-pinch”.
Zap Energy’s “pinch” approach is not new. It may have been observed in lightning effects since the 18th century and has been proposed as a path to fusion power since the 1930s. While pinpricks occur naturally in lightning strikes and solar flares, the challenge for engineers it is to stabilize electrical and magnetic forces long enough in pulses, measured in a millionth of a second, to produce radiation to heat a surrounding curtain of molten metal.
Brian Nelson, a retired nuclear engineer from the University of Washington and chief technology officer for Zap Energy, said the company had successfully injected plasma into a new, more powerful experimental reactor core. He is now completing a power supply that is designed to provide enough energy to allow the company to prove that it is possible to produce more energy than it consumes.
If their system proves viable, the Zap researchers say, it will be much cheaper than competing systems based on magnet and laser confinement. It is expected to cost about the same as traditional nuclear power.
The researchers who attempted the Z-pinch design found it impossible to stabilize the plasma and abandoned the idea in favor of the magnetic approach, known as a Tokamak reactor.
Advances in stabilizing the magnetic field generated by plasma flow by physicists at the University of Washington led the group to establish Zap Energy in 2017. The company has raised more than $160 million, including a series of investments from Chevron.
Recent technical advances in fusion fuels and advanced magnets have led to a sharp rise in private investment, according to the Fusion Industry Association. There are 35 merger companies around the world, and private funding has exceeded $4 billion, including from well-known tech investors like Sam Altman, Jeff Bezos, John Doerr, Bill Gates, and Chris Sacca. Gates and Sacca invested in Zap’s most recent funding round.
But there are still vocal skeptics who argue that progress in fusion energy research is largely a mirage and that recent investments are unlikely to translate into commercial fusion systems anytime soon.
Last fall, Daniel Jassby, a retired plasma physicist from Princeton University, wrote in an American Physical Society newsletter that the United States was in the midst of another round of “fusion energy rush,” which has gone on and on. come every decade since the 1950s. He argued that claims made by start-ups that they were on their way to successfully building systems that produced more energy than they consumed had no basis in reality.
“That these claims are widely believed is due solely to the effective propaganda of drug company promoters and spokespersons,” he wrote.
Physicists and executives at Zap Energy said in interviews last week that they believed they were within a year of showing that their approach was capable of reaching the long-sought energy balance point.
If they do, they will have succeeded where a series of research efforts, dating back to the middle of the last century, have failed.
Physicists at Zap Energy said they had defended the “scaling” power of their approach to producing a strong increase in neutrons in a series of peer-reviewed technical papers that documented computer-generated simulations that they would soon begin testing.
A power plant version of the system would encase the reactor core in moving molten metal to capture bursts of neutrons that would generate intense heat, which would be converted to steam that would in turn generate electricity.
Each reactor core will produce about 50 megawatts of electricity, roughly enough to power at least 8,000 homes, said Uri Shumlak, a physicist and professor at the University of Washington who co-founded Zap Energy.
Their technical challenge now is to confirm what they have simulated by computer, he said. That will include ensuring that the Z-pinch fusion section of the plasma remains stable and that they can design an electrode that can survive the intense melting environment of the reactor.
Mr. Conway said he hoped Zap could prove its concept quickly, unlike the big, high-cost development efforts of the past, which have been like “building a billion-dollar iPhone prototype every 10 years.”