General Discussion
In reply to the discussion: RESIDENTS OF OCOTILLO AND BOULEVARD SPEAK OUT, SHARE SAFETY FEARS AFTER TURBINE BLADE FALLS [View all]badtoworse
(5,957 posts)Last edited Fri May 17, 2013, 04:02 PM - Edit history (1)
If it's not properly sited, flicker and noise will drive your neighbors crazy and many areas have passed zoning ordinances requiring a substantial setback from the nearest house (I've heard of requirements as much as 1000 meters). Impacts to bats and birds are a dirty little secret - wind turbines kill hundreds of thousands of birds every year, but this fact is rarely discussed. There is also the danger of a fire in the nacelle.
As far as a blade being thrown a mile, I doubt that could happen if the blade stayed in one piece, but if the blade broke up, I believe it could happen in a "runaway" situation. If the coupling broke, there would be no load on the rotor, i.e. nothing to keep the rotor from spinning faster than its design rating. Eventually, it would reach a speed where the centrifugal force on the rotor would cause it to break up. I would not be surprised if pieces of the blade could travel a mile in that scenario - the physics would be similar to what drove a medieval trebouchet. (A trebouchet could hurl 200 lb stones 300 meters). Such an occurence would be rare, but I beieve it's possible.
BTW, the turbine in the picture is a small one (Siemens 1.3 MW). The blades are only 31 meters long and the tower is 68 meters high. There are turbines being produced today that are mounted on 126 meter towers and these turbines have blades that are more than 100 meters long.