October 4, 2022

A startup founded by scientists at the Massachusetts Institute of Technology says it is nearing a technological milestone that could bring the world of fusion energy one step closer that scientists had missed for decades.

Researchers from MIT’s Plasma Science and Fusion Center and engineers from Commonwealth Fusion Systems have started testing an extremely powerful magnet that is needed to generate immense heat that can then be converted into electricity. It would open the gates to what they believed could eventually be a fusion reactor.

Fusion energy has long been seen as one of the most important technologies to combat the effects of climate change, as it could produce a wealth of inexpensive clean energy.

But despite decades of investments and often too aggressive promises, fusion research has not paid off. Although there is a long history of international experimentation, scientists have not yet developed fusion systems that generate more electricity than they use.

Like traditional nuclear fission, which splits atoms, fusion energy would not consume fossil fuels or produce greenhouse gases. It would be more desirable than fission because its fuel, usually hydrogen isotopes, is more abundant than the uranium used in current nuclear power plants, and because fusion facilities would produce less hazardous and less radioactive waste.

Although a breakthrough in fusion energy is difficult to pin down, it is still viewed as one of the possible high-tech ways to end dependence on fossil fuels. And some researchers believe that fusion research could finally take a leap forward this decade.

More than two dozen private companies in the United States, Europe, China, and Australia, as well as government-funded consortia, are now investing heavily in building commercial fusion reactors. Total investments from the likes of Bill Gates and Jeff Bezos are approaching $ 2 billion.

The federal government also spends about $ 600 million each year on fusion research, and there’s a proposed change to add $ 1 billion to the Biden government’s infrastructure bill, said Andrew Holland, executive director of the Fusion Industry Association.

Some of the startups and consortia are building powerful lasers to create fusion reactions, while others are researching new fuels. Most of them share a similar vision – that they will be able to prove that their technology can produce electricity at competitive prices this decade and build commercial facilities to inject electricity into the power grids soon after 2030.

The Commonwealth’s new magnet, which will be one of the most powerful in the world, will be a crucial component in a compact nuclear fusion reactor called a tokamak, a design that uses magnetic forces to compress plasma until it is hotter than the sun. The reactor looks like a donut-shaped glass surrounded by magnets. Soviet physicists originally envisioned it in the 1950s.

Commonwealth Fusion executives claim the magnet is a major technological breakthrough that will make tokamak designs commercially viable for the first time. They say they are not ready to test their prototype reactor yet, but the researchers are finishing the magnet and are hoping it will be functional by 2025.

The scientists in Massachusetts hope to demonstrate this month a magnetic field almost twice as strong as the magnets a global consortium of the European Union and six other countries is set to use to assemble a reactor in Cadarache, France. The consortium hopes to start generating electricity at the site in 2035.

“If you go to a much higher magnetic field, you can switch to a much smaller size,” said Bob Mumgaard, a plasma physicist and chief executive of the Commonwealth. If it were possible to build a device that was only one-fiftieth the size of the planned reactor in France – which will be about the size of a soccer field – it could generate almost as much electricity.

The Commonwealth’s magnet will be one of 20 used to create a donut-shaped jar in a room roughly the size of a tennis court. This year Commonwealth built 47 acres in Devens, Massachusetts, where it will build both its prototype reactor and a magnet factory. The magnets are made by applying a thin film of exotic materials to a videotape-like carrier, which is then wrapped around a bottle that is used to contain the fusion reaction.

Commonwealth, which has raised more than $ 215 million to date and employs 100 people, received a significant boost last year when physicists at MIT’s Plasma Science and Fusion Center and the company published seven peer-reviewed articles in the Journal of Plasma Physics in which it was stated that the reactor will work as planned.

What remains to be proven is that the prototype Commonwealth reactor can produce more energy than it consumes, a skill that physicists define as Q greater than 1. The company hopes that its prototype will produce ten times the energy it needs when completed.

The best efforts to get a positive energy output from a fusion reactor so far have been made by the Joint European Torus or JET project, a tokamak that went live in 1983 in Oxfordshire, England. Before it was shut down a decade ago, the device could produce 16 megawatts of fusion power with a consumption of 24 megawatts.

Commonwealth must also convince skeptics that fusion reactors can produce electricity competitively. The falling cost of other alternative energies and the substantial cost of building fusion reactors on a large scale are potential obstacles.

Princeton University retired plasma physicist Daniel Jassby has written critical of the commercial potential of fusion energy in the Bulletin of the Atomic Scientists and Physics & Society. He described some of the start-ups as operating in the field of “voodoo fusion energy”. Some companies have not yet proven that their technologies trigger fusion reactions.

He separates Commonwealth from this category because tokamak designs created fusion energy. However, he argues that new fusion technologies are unlikely to produce cheap electricity.

“Your claims are unjustified,” said Jassby in an interview. “You may at some point be able to get something like this working, but not in the timeframe you are talking about.”

In response, Mr. Mumgaard said that Mr. Jassby is not considering the power of the new technological advances that his Commonwealth and MIT researchers will soon achieve.

He said that unlike other energy sources, fusion would produce energy largely without a resource. “You add up all the costs, the cost of normal stuff like concrete and steel, and it’ll do as much electricity as a gas plant but without paying for the gas,” said Mr. Mumgaard.