Fiona MacDonald in Science Alert:
Scientists at Massachusetts Institute for Technology (MIT) in the US have designed a 6.6-metre-wide fusion reactor that they say could provide electricity to around 100,000 people. Even better, it could be up and running within 10 years, according to their calculations.
For decades, scientists have been trying to find a way to harness nuclear fusion – the reaction that powers stars – because of its ability to produce almost-unlimited energy supplies using little more than seawater, and without emitting greenhouse gasses. But despite many promising designs, finding a way to contain and commercialise the reaction on Earth has proven far more challenging than imagined. In fact it's a long-running joke among scientists that practical nuclear fusion power plants are just 30 years away – and always will be.
But not only does the new MIT design promise to be cheaper and smaller than current reactors, it also provides hope that commercial nuclear fusion reactors could become a reality in our lifetime, with the team explaining that similar devices in size and complexity have taken just five years to build.
“Fusion energy is certain to be the most important source of electricity on Earth in the 22nd century, but we need it much sooner than that to avoid catastrophic global warming,” David Kingham, a UK-based nuclear fusion expert who wasn't involved in the research, told David L. Chandler from the MIT news office. “This paper shows a good way to make quicker progress.”
To explain it very simply, nuclear fusion relies on fusing hydrogen atoms together at super-high temperatures to release enormous amounts of energy. This is different to the nuclear fission used in nuclear power plants, which is where scientists split atoms to generate electricity – a process that's less stable and also produces large amounts of nuclear waste.
So why aren't we already using nuclear fusion to generate ridiculous amounts of clean energy?