On Friday, December 5, 2014 12:02:17 AM UTC-6, GM wrote:

Hi Steve,
your explanations are pretty much spot on. The blades are being built with a natural dihedral so they straighten out under load. There are typically around 12-13 airfoils in a wind turbine blade - at least in ours. To further increase the blade tip to tower clearance (we don't call it 'Mast'), the entire drive-train is tilted back by a few degrees.
Not sure which wind project in KS you are referring to but our current generation blades are 47.8m long which makes for a 100m rotor diameter. 120m and 130m rotors on 140m tall towers are already being used in Europe. Our aerodynamisists tell me that these blades have an L/D of around 100:1.
Uli

Mast, tower. To me, towers are those trusses with wires and antennas on them. :-)

Yes, I had noticed the tilt of the box on top to point the axis of rotation up as it goes upwind from the tower. Figured this was also to get blade clearance.

The first one was out near Montezuma. This field has apparently reached obsolescence, as it doesn't seem to be operating any longer. But, all the turbines are still up. Newer ones by Spearville, Harper, etc. Didn't realize they were that big. I know they are really big when you see them being pulled down the highway!

Steve