The problem is that peak energy usage now occurs after sunset. So no matter how many solar panels you stack on your home, around 6-7 PM the coal, oil, and gas power plants all have to spin up to their max capacity. Your solar panels are new less likely to _replace_ a coal power plant, although they do change how many hours a day it runs.
Unfortunately for the power companies, running a coal power plant for 3 hours a day costs just about as much as running it for 8 hours a day. This leads to the power companies naturally feeling rather sour about being forced to credit residents for the power they supply to the grid during low-demand hours. Their costs are staying about the same, but now their revenue stream goes down.
In some regions (Utah/Idaho/Colorado is the one I'm aware of) these power companies are now negotiating with governments for lower and lower solar credits for these kinds of residents and they're winning because the abundance of solar power at mid-day is legitimately creating an oversupply, thus making that energy worth less and less.
I see this causing problems for many of my neighbors, who had solar sales reps factoring in energy buy-back rates from 2016 into 10-year loans models to pay for the solar panels. Soon the energy the power companies pay my neighbors is going to offset their panel loans less and less, which may result in a reversal of the economics that led to them buying the panels in the first place.