teotwaki
Excelsior!
I often wondered whether you could attach an engine fan to the pulley of an alternator and then make a small rack that would hold it off the ground. Run some jumper wires to the battery and when the wind blew... This way you'd be carrying an extra engine cooling fan and alternator as well as getting some power when the wind is blowing. You'd have to turn it to match the wind and it probably wouldn't be as efficient as a dedicated set-up, but it would be spare parts as well.
I can only imagine that a 100 Amp alternator needs a pretty good wind to generate much current