Zap Energy, a fusion energy start-up working on a low-cost path to producing electricity commercially, said last week that it had taken an important step towards testing a system it believes will eventually produce more electricity than it consumes.
The point is seen as a milestone in the solution of the energy challenge. An emerging global industry composed of almost three dozen start-ups and heavily funded government development projects is pursuing a variety of ideas. The approach of Zap Energy is simpler and cheaper than what other companies are doing.
The energy released by splitting atoms is captured by the nuclear power plant. The process includes waste that remains radioactive for hundreds of years. Nuclear fusion is similar to the process that takes place inside the sun, where hydrogen atoms are fused into helium.
Physicists have pursued the idea of commercial power plants based on a controlled fusion reaction for more than 50 years. A power plant that produced more electricity than it consumed and had no radioactivity would be called a power plant. None of the research projects have met the goal. There is growing interest in the technology despite the fear of climate change.
Benj Conway is the president of Zap Energy.
Zap is pursuing an approach pioneered by physicists at the University of Washington and Lawrence Livermore National Laboratory that uses a combination of magnets and light to create a fusion reaction in a small amount of time.
The cloud of particles is compressed by a magnetic field generated by an electrical current as it moves through a two-meter vacuum tube. The technique is called Sheared Flow Z-pinch.
Zap Energy has been using the same approach for a long time. It might have been seen in the effects of lightning strikes as early as the 18th century. The challenge for engineers is stabilizing the electrical and magnetic forces long enough in a millionth of a second to produce radiation to heat a curtain of molten metal.
Brian Nelson, a retired University of Washington nuclear engineer and Zap Energy's chief technology officer, said the company had injected a new and more powerful experimental reactor core. The power supply is being completed to allow the company to prove that they can produce more energy than they consume.
The Zap researchers say that if their system works, it will be less expensive than competing systems based on magnets and lasers. It is expected to cost the same.
The Z-pinch design couldn't be stable and was abandoned in favor of the Tokamak reactor.
Physicists at the University of Washington made advances in stabilizing the magnetic field, which led to the creation of Zap Energy. The company has raised a lot of money.
Private investment has increased due to recent technical advances in fusion fuels and advanced magnets. Private funding for fusion companies has risen to over $4 billion, including from well-known technology investors like Sam Altman, Jeff Bezos and Bill Gates. Mr. Gates and Mr. Sacca were investors in Zap.
There are still skeptics who argue that progress in fusion energy research is a mirage and that recent investments aren't likely to translate into commercial fusion systems anytime soon.
The United States is in the middle of a new wave of fusion energy, according to a newsletter written by a retired physicist. He argued that the claims made by start-up companies that they were on a path to build systems that produced more energy than they consumed were not true.
He wrote that the claims are widely believed because of the effective propaganda of the promoter and laboratory spokesman.
The Zap Energy physicists and executives said in interviews last week that they believed they could reach the break-even point in a year.
They will have succeeded where previous research efforts have failed.
The Zap Energy physicists said they made the case for their approach to produce a steep increase in neutrons in a series of peer-reviewed technical papers.
A power plant version of the system would use molten metal to cover the reactor core in order to capture the bursts of neutrons that would cause intense heat.
According to a University of Washington professor who is a co-founding member of Zap Energy, each reactor core will produce 50megawatts of electricity, enough to power at least 8,000 homes.
They need to confirm what they have done by computer. Ensuring that the Z-pinch fusion section of the plasma remains stable is one of the things that will be done.
The big, high-cost development efforts of the past have been like "building a billion-dollar iPhone prototype every 10 years" according to Mr. Conway.