No, not solar (I know that's much more "free" than this), but thought I'd relate this to everyone... There's a Calif state law (which I verified with the PUC) that states that an electric utility (don't know if it applies to other utils or just electric) can only bill you a maximum of 90 days out if they don't generate bills for you on time. Well, my last SCE bill came in May (for April's usage). After that, time went by, without a bill. I couldn't even view usage online. I called them after a couple months, and was told it was a glitch, and they didn't know when it would be fixed, or the next bill would be generated. I was kind of upset, especially when everyone else in the neighborhood was getting regular bills (who wants a giant bill you have to pay all at once because a utility is too incompetent to bill you for months?) I was told the problem affected a small number of random people. So at first I was upset. But then they told me that if they can't generate their bills, state law says they're only allowed to bill up to 90 days back max -- no more. Well, that made me feel better. So my next bill was finally generated in December -- and sure enough, it's only for 90 days worth (actually, slightly less I think). So I got free electricity for May, June, July, August, and part of Sept. Heck, if they wanted to take more time to fix the problem, that would've been fine with me...
My state (WA) has no such time limit. The law even obligates the public utilities to attempt to recover such omissions as far back as they have reasonable records, as such government assets must not be gifted out here. This has caused some quite nasty bills for some unsuspecting customers when meter mixups, long term estimates in place of actual meter readings, and other snafus are discovered. As a net-zero solar energy producer, I'd certainly hope that this sort of billing 'forgiveness' doesn't apply in reverse to CA's solar homes. Those missing months cover my prime energy production season, the months where I'm feeding energy back to the utility. Home solar customers certainly don't want the lose their net metering credits earned during high production season.
