A CAMBRIDGE STARTUP working with officials at MIT said on Wednesday that it has achieved a major breakthrough in fusion technology that could begin revolutionizing the way energy is produced around the planet as early as 2030.

Fusion produces energy the same way the sun does, by combining atoms under enormous heat. The allure of fusion is the large amount of energy produced, the plentiful source material (hydrogen atoms from water), and the absence of any polluting byproducts. The challenge has always been the huge amount of energy needed to trigger the fusion process; no system has been built yet that uses less energy as an input than it generates as an output.

On Sunday, however, Commonwealth Fusion Systems says it succeeded in operating a magnet strong enough to safely contain a fusion reaction with far less energy than previously required. The magnet, developed over the past three years, is also much smaller in size than other models being tested around the globe.

Maria Zuber, MIT’s Vice president for research.

Dennis Whyte, the director of MIT’s Plasma Science and Fusion Center and the cofounder of Commonwealth Fusion Systems, said the high-temperature superconducting magnet tested on Sunday required only 30 watts of power, compared to the 200 million watts required previously. Whyte said the breakthrough means fusion energy can be produced economically.

Dennis Whyte, the director of MIT’s Plasma Science and Fusion Center and the cofounder of Commonwealth Fusion Systems.

Officials cautioned that much work remains to be done, but they described the new magnet technology as the key to fusion development. They project a prototype of an energy producing fusion system, now under construction in Devens, will come online by 2025 and a commercial fusion power plant will be ready by as early as 2030.

“This test provides reason for hope that in the not too distant future we could have an entirely new technology to deploy in the race to transform the global energy system and slow climate change,” said Maria Zuber, MIT’s vice president for research. “This is not the last barrier to clear. Technology and economic challenges remain, but with this successful test I’m generally optimistic that MIT and CFS teams can advance net positive energy and that could be a game-changer.”

Zuber said a fusion power plant the size of a small high school gym could generate as much electricity as a current day power plant running on fossil fuels. The fusion power plant would run on hydrogen atoms (plentiful from the world’s oceans) and generate no climate-changing pollution. The only byproduct, officials said, would be helium.

Assuming the remaining hurdles can be overcome, Commonwealth Fusion officials said fusion energy has the potential to help the world address climate change on a timetable that could actually spare the planet lasting damage.

Bob Mumgaard, the chief executive officer of Commonwealth Fusion Systems.

Massachusetts, for example, has set a goal of net zero emissions by 2050.  The United States as a whole and other states individually are pursuing similar goals, trying to substitute electricity for the fossil fuels used to heat buildings and run vehicles. Fusion power plants, if they become a reality, could help make that transition possible without accelerating climate change.

Bob Mumgaard, the chief executive officer of Commonwealth Fusion, said the potential is enormous. “If you know how to build a fusion machine, you can have energy without having all of those nasty inputs and outputs of carbon and fossil fuels,” he said. “That’s a very, very clean way to do it and it’s a way that’s inexhaustible and it’s an [energy source] you can put anywhere that doesn’t depend on what resources you have at that location.”

Whyte characterized the potential in more grandiose terms. “You can power our civilization with fusion energy forever,” he said.