ok so, solar, naturally produces the most power during the daytime, when the sun is up, which in places where it's warm is when you get the most significant energy bump due to AC and what not. There is also a bit of a trailing period in the evening where people get back from work and cook dinner/relax and whatever. But that's not super far off from noon peaking in the grand scheme.
Nuclear plants are baseload, so they produce 100% power output for 100% of the time they exist (at least in an ideal world) usually they have a capacity factor of about 80-90% though i've seen plants go past 100% before. This load is super useful for leveling out the power demand overnight, as well as shortening the day time peak loading a little bit. As well as providing a very consistent and regular source of power than can be used for things like hydro storage, and battery charging for example. So paired with a large thermal battery a nuclear plant might even be able to adapt to the midday loading cycle pretty functionally, as it can recoup most of it's lost energy over the night, through the baseload averaging out.
Nuclear plants are actually really well suited to be used with a thermal battery solution (given that they output thermal power, obviously) It's more common for modern plant designs to integrate thermal battery technology to some degree, but those are all gen IV designs, so they don't exist yet.
As for wind, i'm not sure what the effects on it during the day/night cycle is, but i imagine during the day they generally produce more power, though they will also produce some power over night. So those are a relatively low yield but high regularity power source, similar to nuclear, however you have much greater control over them as you can change the blade pitch during rotation in order to increase/decrease output as needed. Though ideally you would always be outputting, as often as possible.
Even in the event that you have a total grid blackout, nuclear plants are a potential source of blackstart power sources, though presumably it's not nearly as big of a deal in a solar plant for example. It's unclear how much those rely on being secondary producers, or how well they can function as primary producers to me. Presumably it will be dealt with at some point if it hasn't been already.