Twenty-five years ago, as a young physicist, I worked on research linked to fusion energy. Nuclear fusion powers the sun and stars through reactions that turn hydrogen nuclei into helium nuclei, and if we could master the process on Earth, we'd have a safe and virtually limitless source of clean energy. At conferences every year, scientists from around the world gathered to discuss the achingly slow progress then being made. Government and university labs have now been trying unsuccessfully for more than 50 years.
The fusion conferences still go on — this month in Opole, Poland, and at the University of Wisconsin in September — but there’s a different tone, and more excitement, as the research finally seems to be bearing fruit and bringing us closer to fusion energy as a viable energy source. A flurry of new startups aim to achieve it within only 15 years, spurred by the belief that nimble private companies may succeed where lumbering government projects have not. Think Elon Musk’s Space Exploration Technologies Corp.