There are small windmills available for purchase. For a while campers and sailing yachts would use them. But they seem to go out of fashion. The problem is: the

There are small windmills available for purchase. For a while campers and sailing yachts would use them. But they seem to go out of fashion. The problem is: the efficiency goes up with the size also, there is more wind the higher you go. On top of all of that, windmills are quite noisy. You really cannot use them in residential areas. Solar cells are much easier these days and also cheaper.