But I'm talking about
Nuclear Fusion, which is under heavy research since a lot of years and is much more clean and green than anything.
Under heavy research, yes, but that doesn't give any clues if it will ever be ready for commercial use.
For now they spend huge amounts of energy for (iirc) split seconds of fusion. Probably the scientists still need one more breakthrough to make it stable/self sustaining and that could take a while...
It could be a nice dream of cheap energy - cheap/self-sustaining enough that after a while it can be seen as clean energy - and when it'll be commercially available it could replace all the other sources for energy, making humans no longer care how much energy they consume and on what, it's still just a dream. Possibly a very distant one, not worthy to be seen in current context.