I have a small collection of stepper motors that I want to use as wind generators. They're low voltage and low amps but I think if I spin them fast enough they'll make useful electricity. As a test I made a small vertical axis wind turbine out of some old coffee cans but it appears that the wind really needs to be blowing somewhere around 7-8mph in order for it to start up on its own. I'll need to build a tachometer to measure volts/rpm, but for now I have a cheap and ugly test unit. I'm considering just plugging in some LEDs and putting it out in the garden.
Also, I just recieved a new treadmill motor, specs are: 260 VDC, 5100 RPM, 5A. I was able to spin it with my fingers and get 12v, so this should be perfect for about 300 rpm horizontal axis wind turbine and about 15v for battery charging. My first attempt at blades will be some simple PVC pipe cut into the proper shape. I'll also need to look into voltage regulator circuits and whatnot, which should be only slightly different than the charging circuit I made for the portable tunes box, because it'll need to handle a significantly higher current.
I have no idea what I need a wind generator for but I've always wanted one.