If wind generation were to become so efficient that it could actually economically replace oil the greenies would discover a host of horrible environmental disasters that would come from it. Their carp is with energy use and production, not so much with the method of its generation. These folks believe in a "sustainable" human population of earth of 500 million or 50 million or some other miniscule number and they believe that any method that can get to that goal is good. Anything that allows an increasing population to thrive or that maintains the present population is Evil.
And you won't see them being the first one's volunteering to leave the planet.