I saw a TV show just recently. It was Engineering Disasters on the Science Channel. It was about wind turbines in the North Sea off of Denmark. Probably made by Vestas wind systems.
It showed another maintenance issue with wind turbines I had never heard of prior. The leading edge of the blade is constantly impacting at 150 mph small bits of debris in the air(sand, grit, salt, etc) this debris eventually breaks down the leading edge of the gel coat/fiberglass. So, technicians have to repel down the blade and cover the leading edge of the blade with this fabric to keep the blade from breaking apart.
Saw that show. I found the part about the blades to be fascinating.