Research into this has been going on for decades, and now start-ups and investors are raising hopes that fusion energy could soon work. It could make electricity significantly cheaper.
The idea is actually simple: in order to generate low-CO₂ energy, you just have to do it like the sun. Our central star is a gigantic fusion reactor. The energy that the star gains from the fusion of atomic nuclei even heats up our planet, which is almost 150 million kilometers from the sun. But implementing what is in itself a simple idea technically is a huge challenge.