 |  Wind turbines have a fixed base, but their blade tips achieve high speeds, a combination that can confuse military radars. |
The U.S. Department of Defense (DOD) released a report last week detailing how wind turbines can interfere with military radar. To detect intruding aircraft and missiles at long ranges, the military relies on a variety of techniques to subtract the radar signal of ground-based "clutter," such as buildings or transmission lines. Unfortunately, these techniques weren't designed to handle large, quickly moving objects such as wind turbine blades, and so the wind turbines cause interference that lowers the effective sensitivity of the military radar. The new DOD report notes that there may be technological solutions to the problem, but for now the only proven solution is to keep wind turbines away from the line of sight of military radars. The report also notes that wind turbines might interfere with air traffic control and weather radars, but defers to the Federal Aviation Administration (FAA) and the National Weather Service on those issues. However, the DOD report notes that air traffic control radars are supplemented by aircraft transponders and flight rules, which lessen the detection burden on the radars. See the report, "The Effect of Windmill Farms on Military Readiness" (PDF 1.2 MB). Download Adobe Reader.