As I understand it, the problem was evening demand, not daytime and that's probably also the real reason why all the empty office buildings aren't helping - most people would probably be out of the office and back home by them. If anything, residential solar makes this problem worse both by making non-solar generation less financially viable and causing a sharp increase in demand for it during the evening as the sun goes down.

The "duck curve".

https://en.wikipedia.org/wiki/Duck_curve