A group of physicists at Massachusetts Institute of Technology (MIT) recently achieved a feat that could pave the way for practical carbon-free power. The achievement was three years in the making . It is a result of intensive research and design work, project leaders say. For the first time, researchers built a large high-temperature superconducting electromagnet that can reach a field strength of 20 tesla — the most powerful magnetic field ever created. This has removed a key hurdle in the generation of clean fusion power, making it possible to build a fusion power plant that can produce more energy than it consumes.

Fusion energy, which powers the Sun, involves two small atoms merging together to make a larger one. No solid material can withstand the temperatures required for it. So, what’s needed is a way to capture and contain something as hot as the Sun’s power source by suspending it in a way that does not come into contact with anything solid. Powerful electromagnetic fields like the one created by MIT researchers can do that job, as per researchers.

These electromagnets could enable building simpler, more compact fusion reactors. The technology can lead to construction of inexpensive and carbon-free power plants, a major factor in curbing the effects of climate change, project leaders at MIT and startup company Commonwealth Fusion Systems (CFS) said.

Maria Zuber, MIT’s vice-president for research, said fusion in a lot of ways is the ultimate clean energy source. The fuel for fusion energy comes from water — a nearly unlimited resource. Also, the amount of power available is “really game-changing.”

Demonstration fusion in a lab has been pursued for long by several researchers with limited success. Developing the new magnet was one of the greatest hurdles. Now that the technology has been successfully demonstrated, the MIT-CFS collaboration is on track to build the world’s first fusion device that can produce more energy than it consumes. That device, called SPARC, is likely to be ready in 2025.

Dennis Whyte, Director, Plasma Science and Fusion Centre at MIT, said there are many challenges to making fusion happen. But once the technology is proven, Whyte saud that this could be a fundamentally new “inexhaustible” source of energy.