Here's one I've been playing around with using the ametek 38 volt motor...

  It's a small 2ft dia x 2ft tall turbine, kind of a quick build for testing purposes.  The ametek is driven by a cog belt 4 to 1 .  It does about 18 watts in a 15 mph wind right now although I think the motor needs just a little less re-drive.   Here is a closer shot of the mounting...

  This actually comes up to speed pretty fast but you can tell it's being held back by the motor considerably.  Opening the circuit it runs up considerably.  

  There is a long bearing tube inside the mount tube that is held in place by 2 bolts clamping it inside the tube for now.  I purchased a couple aluminum cog gears and made some molds from them and cast them in plastic.  I plan to purchase a couple more small cogs to get a 3.5 and 3 to 1 redrive for experimenting.  Belts are cheap, the cogs are pretty pricey.