You may have missed the point.
Overall they use MORE than the solar energy they generate even if they sell some during peak summer daylight hours.
So they have to net buy some electric off the grid.
But the state mandates that the power company gives the solar panel owners $$$ so they pay zero for it.
You know where the companies get the $$. The goal is to use our $$$ to lure us into buying them, O Malley has 2016 plans.
i know they use more, on a cloudy day in particular they probably use 90 or 95% net power from the grid. But if they are truly paying zero for their electric bill as you say, then they are getting 90% free power on those cloudy days. That is beyond ridiculous, it is criminal, mostly because I know the company that leases the systems is cleaning up on subsidies and profit.