From a story by Alec Luhn in the Wisconsin State Journal:

When he got to what he calls “the mid-life crisis age,” Madison resident Jim Taylor, 45, said he figured “Well, I’m going to have to either buy a sports car or do something.'”
For Taylor, that something was installing an 8.4-kilowatt solar panel array on his roof in April — the largest solar-energy system on a Madison residence.
Although he originally intended to supply only his family’s energy needs, he has been selling his excess energy to Madison Gas & Electric the last two months and now could increase his earnings under a new buyback rate proposed by the utility.
Under the proposal, Taylor would sell all of his energy to MGE at a rate of 25 cents per kilowatt-hour and buy back the portion he needs from the utility’s overall pool of renewable energy at about 10 cents per kilowatt-hour.