The wife of a friend of mine asked me whether it could be at all practical to build a wind turbine out of a bicycle wheel, and it was always something I was curious about too. So I set out to find out, looked for ways to simplify, and to use easily available and least-expensive materials.
In 2014 you can build one of those wind turbines for around $60 U.S.
Actually you know what? Forget the charge controller, try without it, just use a single diode only, for a large-ish battery (car size or more) that might work fine.
Have fun reinventing the wheel.
Thanks to Suki, Julianna, Andrew, Anna, and mostly Clarice.