(but less than, say, Minuteman II silos?)
I thought the big money problem with wind has been that it takes a lot of wind to start the turbines, so the penalty for letting the blades go to 0 RPM is high and thus below a certain level of wind (3MPH sticks in my foggy brain?) an electric motor is used to keep the blades turning in case the wind picks up again ... many wind farms turn out to never generate positive amounts of power because of this. The wind farm in the Altamont Pass east of San Francisco has been a joke for 20 years due to this. Maybe it's changing?
/jordan