As long as you build 5-10x redundancy for solar/wind I don't see it, solar and wind are all over the place between the peak and valley outputs. Unless we find a "battery" storage technology that can smooth it out over say a couple of weeks, I don't think countries are going to go for it as the only grid power source. We have nuclear now, and climate change is a huge deal to solve, possibly end of human civilization huge. Note I didn't say solar and wind wouldn't be part of the mix,but as the sole source, it's not going to happen with a 10X or better leap in battery technology (energy density)