Cold Fusion is completely unnecessary. It requires massive amounts of energy to start the reaction and once it's producing any power, it produces hundreds of times more power than we could effectively use. If the public opinion could be changed regarding fission energy we would have more than enough. Thorium was already developed in the 50s and 60s, we just need to implement it.

Why aren't we using thorium then?

Because thorium reactors don't produce weapons-grade plutonium.