Specifically:
In Germany more and more wind turbines are failing. The reason: Support runs out, materials experience fatigue, or it is simply more profitable to replace older models with newer ones. At the same time, the dismantling them is extremely complex.
Dismantling a generator is complex? There is nothing in a windmill that is any more complex than junking an old car. Of course the early windmills are out of date, they are subject to engineers improving the product and process. They are also subject to a simple equation - if you double the diameter of the blades you triple the amount of energy harvested from the wind. So as the manufacturing process improves, the builders are able to increase the size of the rotors and that is what makes the windmills of the past obsolete.
Did they look anything like this?
https://www.google.com/search?q=17th+century+windmills&espv=2&biw=1458&bih=830&tbm=isch&imgil=VpysJnkaeMX6ZM%253A%253BQi-HqOKpRCZiCM%253Bhttp%25253A%25252F%25252Fwww.hollandexploringtours.nl%25252Fguide-windmills.htm&source=iu&pf=m&fir=VpysJnkaeMX6ZM%253A%252CQi-HqOKpRCZiCM%252C_&usg=__UAwT2N01xkwsygpYcFCKK2W_YSc%3D&ved=0ahUKEwia9ZWl17nMAhVJwj4KHU2YCXwQyjcIJw&ei=gmImV5qsJcmE-wHNsKbgBw#imgrc=VpysJnkaeMX6ZM%3A
Decommissioning a nuclear reactor is not only complex but extremely dangerous.