Ideal consumer, from the power network point of view, is as constant as possible. Each time you cut off a consumer node it creates harmonics and surges that need to be compensated upstream. Lots of nodes going on and off simultaneously (and they will as the whole parts of the city have the good sun at the same time) are engineering nightmare, existing grids are just not build to handle it, so they'll need to be upgraded, plus the maintenance costs will go up.