I live in the Chicago burbs and am interested in someone penciling this out. I am also in commercial real estate, and have a pretty good gut on ROI etc. Based on all that I've read and heard, you install solar up here for sustainability purposes, not for investment purposes. Of course if you plan to hold your home for 20 years one might be able to make the argument, but the up front investment in both the premium tile cost and, more importantly, the modification to the electrical distribution equipment makes this a loser from an investment perspective.
I think the Redfin article is dubious, as the home values in the study are so low that I doubt the data is from anywhere within 50 miles of downtown. $185K (or even $300K for that matter) Chicago home buyers are not the target market for solar as they are not going to spend a nickel more than they have to on a failing roof. In fact, some might have to use home equity or other credit vehicles.. . . .I could go on, but you get my drift.
I'll track this to see where this goes, but my back of the napkin math on my 4000 SF home 20 miles north of the city says "no go."
I have a bout a year for someone to convince me otherwise, so have at it!