As you no doubt remember, the Virginia earthquake that shook the entire northeast of the U.S. last week also shook Virginia's North Anna nuclear plant offline. Subsequently I read about the possibility of some coal plants in Texas having to shut down because of the drought (since power plants heat water into steam to drive turbines, if there's an extreme water shortage...). The article about the coal plants came up in another, somewhat gloating piece defending wind power against the criticism that it isn't consistent or reliable as an energy source.
And then came word that Hurricane Irene's path would take it right up the coast. What do wind farms do in a hurricane? We've all seen that one clip of the wind turbine that spins out of control and destroys itself. I know that was an anomaly, but still, how do they keep those things from buzzing to the moon when a hurricane hits?
I'm thinking, for example, of that off-shore wind farm planned for off Cape Cod.
The answer is that either by automatic means or through manual preventive measures, the the blades of the turbine feather.
Not having any experience in propeller-based fields I struggled to think of what properties Farah Fawcett/Scott Baio 80s hairstyles had that would help wind turbines survive high winds. Wrong kind of feather.
The answer is that the blades twist in their sockets so they don't catch the wind anymore. Combined with a braking sytem, they endure the wind until it returns to a more productive speed.
A clearer animated example after the jump...