> So for filling in the gaps we NEED something else, no way around it. Between 'cheap' coal, oil, natural gas, or covering land masses with biofuel crops, a modern design nuclear plant isn't a bad option.
Yeah, but the thing is, it is a bad option.
Forget fallout, meltdowns etc. Nuclear is expensive per kW.
Because of that nuclear plants are pretty much run flat out, as baseload, to get the kWh cost down to something that is remotely competitive. I mean, you can run them at half power, but when you do that, those kWh that are made are made at twice the price; and they weren't all that cheap to start with. So, using a nuclear plant to fill in for the 20% of time; isn't going to happen.
No, for filling in when both the wind and sun aren't producing, you need a cheap source of power; a gas turbine, or a hydroelectric plant or a diesel plant or similar, something ideally using a biofuel.