Years ago, someone at UC Berkley calculated that if we generated half of our electric power from wind, we would drastically alter US Weather Patterns. When a wind turbine blade turns it is taking energy out of weather systems. If the entire west slope of the Pacific Coast were covered in wind mills, it might create a rain shadow like effect, and might severely reduce the ammount of rain falling on the west slope of the Rockies. Of course we all know how much the west depends on Colorado River water. There is no free lunch in nature.