Unless your friend who builds the turbine gives it to you for free, you're probably looking at well in excess of $600 for just the basics required. Then you have to hassle with keeping batteries in condition, what to do when the wind REALLY blows (do the blades feather, do you have to take the turbine down, or does the wind just knock it over), dealing with ice/snow, maintenance, etc., etc. Further, as others have pointed out, if your chicken coop is in a location with enough wind to reliably power a turbine, you really need to move the coop.
Rent a trencher, run an electric line to the coop and be done with it.