Not the parent poster, but you should add what's actually being built: a lot of gas plants. They're cleaner than coal, but lets be honest, still not particularly good for the environment.
To be fair, that statement was in the grandparent and not the post I replied to. However, I'd argue
> Large steam thermal baseload plants are increasingly uncompetitive, coal or nuclear.
is generally wrong, since gas power plants are "large steam thermal baseload plants" and they're very much competitive. Large baseload plants are just as necessary now as they used to be since we'll still need power when the wind doesn't blow. The problem is nuclear needs to run at max power all the time to be profitable.
There's ways that you can not run at max power with nuclear reactors. Especially if you include advances from modern reactors (i.e. reactors that weren't designed 50 years ago).
You can also use that energy to charge batteries or pump water uphill the same way you would with excess solar and wind power. Doing so means you need a lower baseload.
Also, another idea, why not use that excess energy to sequester carbon? We do need to be carbon negative.
Technically, there are ways to run nuclear reactors at below full power. But economically, it's ruinous to do so. Almost all the costs of a nuclear plant are fixed. The already poor levelized cost of the plant's output becomes even worse.
You could charge batteries with nuclear output, but why do so, when other sources are cheaper? And the battery charging can be moved around in time, so the intermittency of those sources is less of a problem.
Similarly, why use expensive energy to sequester carbon when cheap energy could be used instead?
No, you are mistaken. CC plants have a steam bottoming cycle, but 2/3rds of the power comes from the combustion turbine front end. This gives them a very large advantage over systems where all the power has to go through the steam. And simple cycle plants require no heat exchangers, steam cycle, or cooling water at all.
