Which I think is where solar/wind/hydro (in places that aren't the hoover dam...) make the most sense. Topping off comparatively clean sources like nuclear (or, preferably, actually clean sources) either through only turning them on when needed or having them charge capacitors. Hell, the UK have even been doing it, to a lesser extent, through pumped storage (think of them like really big water-based capacitors that you charge during non-peak times)

My point was more in balancing out the common misconception of "Let's just put a solar cell on every roof".