A common concern with wind farms is that they can kill birds and bats flying through. The most high profile example is the Altamont Pass farm in California, where golden eagles and other species have had trouble navigating the tightly packed turbines. A company called DeTect, though, thinks they have a way to mitigate wind energy's impacts on birds and bats.
The Merlin Avian Radar System plants a radar transmitter in the midst of a wind farm, and looks out for migratory birds that might be passing through. If it sees some and determines they might fly into the midst of the turbines, it can automatically shut down the turbines in question to allow the birds' safe passage. A couple of these systems are already up and running, at wind farms in Texas (pictured).
The system has a range of 2-6 miles, meaning if a group of migratory birds are on their way, there should be ample time to shut down the wind farm until they're through (it takes less than one minute to get them down below 1 RPM, and five minutes to get them all off completely). I spoke with Helen Lewis, a company representative, at the American Wind Energy Association's Offshore Wind Expo going on in Baltimore yesterday, and she told me that their systems can also simply be connected to bird deterrent devices, like noise or light generators, to keep the birds from flying in to dangerous areas in the first place.
One problem with this idea, of course, is simply that some wind farm operators may not want to shut down the turbines every time a few birds fly into their midst. But if there are spots where bird issues might prevent a wind facility from going up in the first place, this type of system could allow it to move forward with a promise that it will be used as intended.
This short animation gives a good idea of how the system is meant to work:
This seems like a great idea, but it remains to be seen whether it gains any real traction among wind developers. The bird problem is certainly something worth trying to mitigate, but it is important to keep it in perspective: some experts say as many as one billion birds are killed every year from collisions with buildings, far, far outstripping any effects wind farms might have.
(Image and animation via DeTect)