Hurricanes are when you want your system <i>stowed</i>.<p>The power available from wind goes up as the cube of the windspeed.<p>So you go from generating lots of power and &#x27;doing ok&#x27; to catastrophic failure and &#x27;bits and pieces&#x27; over <i>one</i> doubling. An 8 MW output turbine that suddenly has to deal with 100 MW had better be shut-down and furled well before that moment arrives. Otherwise you can bring your vacuum cleaner and a mop.<p>There is at this moment no blade material strong enough to deal with hurricane level winds while operating at rated speed.<p>It works like this:<p>Wind is moving air and moving air has mass. So if you move that mass twice as fast the energy that it contains is e=mv^2 the square of the energy that it contained before impacting on the blades.<p>But it is also <i>more air</i>, twice as much air will pass through the rotor blades in the same amount of time, so you get to double again. Hence the factor of 8.<p>Most windmills will shut down well before they reach the danger point, they simply furl their blades to ride out the storm. They will track the wind even in this state because if the wind would hit the rotor at an angle that could start up the rotor again and then all hell will break loose because the brake will not be able to withstand the rotor once it reaches a certain speed, it will simply burn up and from there to the bits and pieces stage it is less than a few minutes.<p>There are some youtube movies about wind turbines that fail to switch to safe mode before a storm hits, not pretty.