The Economist has just run the best article on nuclear fusion that I’ve read for a while. He’re the denouement:
Even if stellarators work well, the 30-year rule, or something pretty close to it, is likely to apply. And, by the middle of the century, the world’s energy landscape will probably look completely different from now. Perhaps there will, indeed, be a gaping hole in supply that only fusion can plug. More likely, cheap photovoltaic and energy-storage technology will mean that much of humanity’s energy comes from a different fusion reactor—one 150m kilometres away, called the sun.
You can read it all here.