Very nice tone and saturation. I think you should have cropped a bit off the left because that emptiness combined with the tree on the right makes the picture feel too lopsided. A longer exposure giving motion to the windmill would have been nice too bad the clouds weren't cooperating with you.
Around here, all kinds of people have these in their yards as a decoration. Also, ranchers still use the big ones to provide the power to the pumps that fill stock tanks.
Beautiful picture!!! I just love the photos like this that fit the challenge, but also give you something awesome and interesting to look at as well. Good job!
I wouldn't call this technology obsolete, because it's very much on the upswing. I wouldn't call this object "worn out" or otherwise useless, since it seems to be in good repair and functional. So I'm not sure how this really fits hte challenge. But it's a nice shot anyway.