If all goes as planned, the US will eliminate all greenhouse gas emissions from its electricity sector by 2035 – an ambitious goal set by President-elect Joe Biden, relying in large part on a sharp increase in wind and solar energy generation. That 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 papers that their design should work, restoring optimism that this clean, limitless power source will help mitigate the climate crisis.
While the new reactor still remains in early development, scientists hope it will 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 meeting energy requirements in a warming world. “Fusion seems like one of the possible solutions to get ourselves out of our impending climate disaster,” he said.
Nuclear fusion, the physical process that powers our sun, occurs when atoms are pushed together at extremely high temperatures and pressure, causing them to release tremendous amounts of energy by merging into heavier atoms.
Since it was first discovered last century, scientists have sought to harness fusion, an extremely dense form of power whose fuel – hydrogen isotopes – are abundant and replenishable. Moreover, fusion produces no greenhouse gases or carbon, and unlike fission nuclear reactors, carries no risk of meltdown.
Harnessing this form of nuclear power, though, has proven extremely difficult, requiring heating a soup of subatomic particles, called plasma, to hundreds of millions of degrees – far too hot for any material container to withstand. To work around this, scientists developed a donut-shaped chamber with a strong magnetic field running through it, called a tokamak, which suspends the plasma in place.
MIT scientists and a spinoff company, Commonwealth Fusion Systems, began designing the new reactor, which is more compact than its predecessors, in early 2018, and will start construction in the first half of next year. If their timeline goes as planned, the reactor, called Sparc, will be capable of producing electricity for the grid by 2030, according to researchers and company officials. This would be far faster than existing major fusion power initiatives.