On this episode of Science to Save the World, we bring up a long-discussed topic: bringing the power of the Sun to Earth.
Nuclear fusion holds the promise of clean, limitless energy, but it is notorious for always being “30 years away”. It’s possible that we may finally be reducing that time frame.
Nuclear fusion offers the alluring proposition of limitless, renewable energy. Now, scientists at MIT have announced a pivotal moment in the technology’s development. Fusion occurs when atomic nuclei combine to form larger elements, releasing huge amounts of energy in the process. This is how stars like our sun produce their energy.
So far scientists have not been able to achieve a fusion reaction that produces more energy than it consumes, but that may be changing. Superconducting magnets are one way to contain the ultra-high temperatures needed to produce such a reaction. And researchers just created the most powerful magnet yet.
For the first time, a magnet of this type has been able to generate a magnetic field strong enough for fusion to occur. The magnet uses a new superconducting material called ReBCO. It’s made up of 16 plates stacked together, and is about 10 feet tall. It can reach a record-breaking magnetic field strength of 20 tesla with a two-week run-up time, which the researchers claim is adequate to induce nuclear fusion. They claim the magnetic field is around 500,000 times stronger than Earth’s natural field. That’s twice as powerful as earlier superconducting magnets!
With these capabilities demonstrated, MIT scientists and their collaborators at the startup Commonwealth Fusion Systems (CFS) are now working to fit it into a nuclear fusion reactor. They plan to use a circular magnetic containment device called a tokamak to heat trapped plasma to temperatures of 100 million degrees Celsius or more, achieving a fusion reaction. CFS researchers say this new high-field magnet allows tokamaks to be substantially smaller — and hence cheaper and easier to build.
Hydrogen isotopes in water would fuel the reactor and because ocean water is plentiful, these reactors could run virtually forever. Even better, the fusion process generates relatively little waste! The MIT/CFS team hopes to have a test plant up and running by 2025.
If the technology can be scaled, clean, sustainable, cost-effective fusion power will become incorporated into the power grid. There is still much work to be done and many obstacles to overcome, but the team now has achieved an ultra-powerful magnet, one of its greatest goals. With this development, faster progress can be made on solving fusion’s remaining problems. And time is of the essence. Earth’s atmosphere is rapidly warming, and humanity needs to significantly reduce carbon emissions right away.
According to MIT geophysicist Maria Zuber, “Fusion in a lot of ways is the ultimate clean energy source. The amount of power that is available is really game-changing.”