The demand for energy, especially electricity, is rising worldwide despite climate change. For many decades, people have dreamed of harnessing the Sun’s energy source – the fusion of light atomic nuclei – cleanly and reliably on Earth to generate electricity. But turning this dream into reality has so far proved to be a rocky road with an uncertain outcome. However, a recent scientific breakthrough in the United States is currently fuelling new enthusiasm and investment, including in Germany. But how far have we truly come? Could this be the solution to all our energy problems?