Comment A clean and powerfull energy source already exists (Score 1) 350
It is the Sun.
All we need to do is to create enough solar cells and enough batteries so as that we can always have power.
If the Sun is producing 4000000000000000000000000000 watts per second, we are, as humanity, simply fools, in that we have the absolutely best power source right above our heads and we are not using it.