[cyberax]

No country in the world has 100% solar+wind power supply. Even tiny island countries have to use expensive diesel to supply guaranteed power.

And once you have diesel generators, it turns out that batteries are more expensive than just buying a bit more fuel.

[nutjob2]

In the long term nations will likely end up with whatever renewables work for them (hydro/solar/wind/thermal) plus the appropriate amount of batteries and expensive, low use (stored) gas/oil plants for "emergencies" where the renewables do not deliver and the batteries might be exhausted. Some nukes will be in the mix obviously but they will not be widespread globally.

The future is all about sovereign power generation and distributed reliability.