If all goes as planned, the United States will eliminate all greenhouse gas emissions from its electricity sector by 2035, an ambitious goal set by President-elect Joe Biden, based in large part on a sharp increase in generation. of wind and solar energy. This plan may soon get a boost from nuclear fusion, a powerful technology that until recently had seemed far out of reach.
Researchers developing a nuclear fusion reactor that can generate more energy than it consumes have shown in a series of recent articles that its design should work, restoring the optimism that this source of clean, unlimited energy will help mitigate the climate crisis.
Although the new reactor is still in its early stages of development, scientists expect it to be able to start producing electricity by the end of the decade. Martin Greenwald, one of the project’s senior scientists, said a key motivation for the ambitious timeline is to meet energy requirements in a warming world. “The merger seems like one of the possible solutions to get out of our impending climate disaster,” he said.
Nuclear fusion, the physical process that feeds our sun, occurs when atoms bond at extremely high temperatures and pressures, causing them to release huge amounts of energy by merging into heavier atoms.
Since it was first discovered last century, scientists have tried to take advantage of fusion, an extremely dense form of energy whose fuel, hydrogen isotopes, is abundant and can be replenished. In addition, fusion does not produce greenhouse gases or carbon and, unlike fission nuclear reactors, poses no risk of collapse.
Harnessing this form of nuclear power, however, has proven extremely difficult, as it requires heating a soup of subatomic particles, called plasma, to hundreds of millions of degrees, too hot to withstand any container of material. To solve this, the scientists developed a donut-shaped chamber with a strong magnetic field running through it, called a tokamak, which suspends the plasma in place.
Scientists at MIT and a spin-off company, Commonwealth Fusion Systems, began designing the new reactor, more compact than its predecessors, in early 2018 and construction will begin in the first half of next year. If its schedule goes according to plan, the reactor, called Sparc, will be able to produce electricity for the grid by 2030, according to researchers and company officials. This would be much faster than the major existing merger power initiatives.
Existing reactor designs are too large and expensive to realistically generate electricity for consumers. Using state-of-the-art ultra-strong magnets, MIT and Commonwealth Fusion teams hope to manufacture a tokamak reactor that is compact, efficient and scalable. “What we’ve really done is combine an existing science with new material to open up new possibilities,” Greenwald said.
Having shown that the Sparc device can theoretically produce more energy than is required to be published in research published in September, the next step is to build the reactor, followed by a pilot plant that will generate electricity in the net.
Scientists and businessmen have long promised that fusion is just around the corner, only to run into insurmountable problems. This has created reluctance to invest in it, mainly because wind, solar and other renewable energies, although less powerful than fusion, have become more efficient and profitable.
But the tide is changing. In Biden’s $ 2 million plan, he named advanced nuclear technologies as part of the decarbonization strategy, the first time Democrats have backed nuclear power since 1972. There is also significant investment coming from Private sources, including some of the major companies merging as a better long-term pivot than wind and solar.
According to Bob Mumgaard, chief executive of Commonwealth Fusion, the goal is not to use the merger to replace solar and wind, but to complement them. “There are things that will be difficult to do with renewable energy alone, on an industrial scale, like feeding big cities or manufacturing,” he said. “This is where the merger can come in.”
The plasma science community is generally enthusiastic about Sparc’s progress, although some question the ambitious timeline, given the difficulties of engineering and regulation.
Daniel Jassby, who worked as a research scientist at the Princeton Plasma Physics Laboratory for 25 years, is skeptical about whether a fusion reactor like SPARC will ever provide a feasible alternative energy source. Tritium, one of the hydrogen isotopes Sparc will use as fuel, does not occur naturally and will have to be produced, he said.
The MIT team proposes that this substance be continuously regenerated by the fusion reaction itself. But Jassby believes this will require a lot of electricity, which will prohibitively make the reactor more expensive. “If we consider that we get solar and wind energy for free, relying on the fusion reaction would be foolish,” he said.
Mumgaard admits that the challenges ahead are daunting. But he remains confident.
“There is a broader trend in recognizing the importance of climate and that we need all hands on deck,” he said. “We got into this problem with technology, but with merger there are great opportunities to solve it with technology.”