There's a guy and his wife who live in central Kansas with his wife. They bought a missile silo, some twenty years ago and converted it into living space and power it with solar (and I think wind). According to articles that get published every now and then they got their money back, according to them, in 7 years.
I also knew a guy who has a farm out West of here who had a wind turbine put up that runs into the grid as opposed to powering his house. With the credits he said he got his money back in 2 years, I believe.