I'm curious of how much power you can actually get out of this puppy? Or how much one can get from wind-power in general.

There was a project started in my city (Toronto, Canada) some few years ago, where they would be putting up a series of windmills and solar panels around the city and along the highways to try to create some form of extra 'green' energy. I'm just wondering how much of an impact that could make, forgetting of course the cost of building for now.