Wind turbines can be a radar operator's worst nightmare. By scrambling radar waves as blades spin faster or slower, large wind farms are sometimes capable of erasing airplanes from radar screens completely. But a Danish wind turbine company and a UK defense contractor may have found a solution by unveiling the first "stealth" wind-turbine blade last month.
Danish company Vestas and UK contractor QinetiQ constructed the wind turbines with radar-absorbing materials that included glass-reinforced epoxy and plastic foam, not the concept used in stealth aircraft. That produced a smaller signature during testing of a wind turbine with two stealth blades.
Such stealth technology may help wind farms avoid problems with short-wave radar. But a Homeland Security study last year found that the technology still falls short in preventing interference with long-wavelength L-band radars used by U.S. air security. A Vestas representative countered the study by telling Technology Review that the company has also demonstrated an L-band radar absorber.
Concerns over aviation radar interference have already held up development of many wind farms worldwide, including a 130-turbine farm in Massachusett's Nantucket Sound. They also compelled the UK government to join Raytheon Canada in trying to modify air-traffic control systems so that they can recognize and ignore wind farm radar signatures.
Still, a final solution may only arrive when older radar systems get upgraded and become more capable of dealing with wind turbine signatures.
[via Technology Review]
Im not sure how the Netherlands are involved, but Vestas is certainly a danish company :)
You're quite right, thanks for the catch!
Now to if they can only make them invisible.
Well, now all they have to worry about is birds. If they put LED's on the blades, and whistles on the blade tips, maybe the ground wouldn't be littered with hapless birds that ran into them.