Tom: You forgot to mention that when the speed gets really high they lock up semi-permanently until they can be inspected for damage from bad storms and tornados. We recently had a tornado in Central Ontario and most of the wind turbines in the area locked themselves up for a few weeks. A colleague of mine explained why. <br><br>...And that is something you may not know!<br><br>(I could be wrong, so research it before you quite me on it.)