Re: Now build a few dozen more...
"Sorry, folks, you wanted wind and solar to power nations.
No, I never did, because it cant."
Indeed, this needs more repeating. Some separation of the renewables into things that are grid level supply (like hydro), grid level but part time (big wind, solar concentrators), and stuff that is effectively small scale demand reduction (rooftop solar, micro wind/hydro, insulation).
I've got some of the things that "count" as renewables, but I'm under no illusions that my dozen solar panels and three batteries would do anything other than allow me to scrape by and involve scheduling my power usage in ways that would drive me nuts. Good as a money saver, but not replacing the grid anytime soon. Hell, even if I ran a diesel generator it'd still be more hassle than just paying for the grid.
While I do agree with your sentiments about generation, but nuclear seems an odd comparison, since there hasn't been a nuke built in the UK for ~30 years, so calcualting it's costs are pretty bunk as a comparison. Gas, waste, bio fuel and mini hydro (in about that order) are what the UK appears to have built, and while I <3 mini hydro it's never going to be viable* for the UK as a generation source.
* based on NZ, which has masses of hydro, has mothballed and abandoned working hydro plants, and has 1/20th the population, hydro only does 50-60% of the base load, or 5-6% of the UK, if the UK had an equivalent to the mighty Waikato.