I had a small 10" household fan that must have developed a shorted motor
winding, and began to trip the breaker. I tossed it in my scrap metal
pile. One windy day I saw the fan blade spinning from the wind, and
decided to mount it on a pole just for fun. Now on windy days it spins
like crazy. After a few years outdoors, it became noisy. I guess the
bearings were dry, so I oiled them. Now it spins well again.

Anyhow, last week I got to thinking if there was any electric being
generated while it was spinning. I put a meter across the cord but read
nothing. Of course since this motor was apparently shorted, it was kind
of stupid to expect any output power.

However, if I was to take a working fan and do the same thing, would I
get any power out of it? A motor is similar to a generator, but is it
capable of generating power?

My thoughts are (if this works), are to put a fan outside with a small
cover over the motor (to keep water out), connect it to some rectifier
diodes, and use it to charge car batteries. I suppose I'd have to rig a
voltage regulator too. I'm not sure what kind of voltage would come
from a 120v AC motor?