If you buy a motor which is too low-powered to cope with high wind speeds, you'll find that the turbine's blade can't handle the torque, and very soon its components will start to degrade, and your turbine will require regular (and costly) maintenance. Thus, it is paramount you buy a motor with the capacity to deal with the wind speeds in your area (though, as we've stated in the previous FAQ, it should also not be overpowered, as this can be detrimental, too).