Who knew that one of the biggest problems in the successful intstallation of wind turbines here, there are everywhere is... radar?
Turns out, wind turbines are getting picked up by radars - and this noise is confusing military and civilian aircraft monitors in densely populated continental europe. (This is not so much a problem in sparsely populated US).
And turns out a British company called qinetiq has developed a way to screen the blades from radar without using a lot of paint on the blade. (Using an absorbent layer on the blade is a non-starter of an idea, considering that these things flex).