A BBC Business news item today on the possibility of nuclear fusion reactors may be getting closer to a reality:
https://www.bbc.co.uk/news/business-46219656
There's a big difference between nuclear fusion reactors and nuclear fission reactors which have been around for years. Fusion ones would produce vastly more energy from just a small amount of material and would solve energy problems.
The problem is that at present to create a fusion requires more energy going in than being generated and to be able to make a reactor strong enough to be able to sustain the huge pressures and high temperatures needed.
If it wasn't so cloudy you would be able to see a nuclear fusion reactor up in the sky.