Windmill with Funnel/Cone
@Fleebell: Why would I loose the ability to turn the turbine with a large cone?
@A.T.: Thanks for the suggestion :)
Do you happen to know how much more energy a shaped "shroud" will capture in comparison to the cone? [estimate?]
Also, the Dyson fan video is interesting (and I looked up some more information about them online), but what are you specifically suggesting? Are you referring to only its shape, or the way that it functions as well?