By Lena Babaeva Coradini

This seems to be a frequent occurrence: "Wind Turbine Projects Run Into Resistance."

Because of its concerns, the Defense Department has emerged as a formidable opponent of wind projects in direct conflict with another branch of the federal government, the Energy Department, which is spending billions of dollars on wind projects as part of President Obama’s broader effort to promote renewable energy.

“I call it the train wreck of the 2000s,” said Gary Seifert, who has been studying the radar-wind energy clash at the Idaho National Laboratory, an Energy Department research facility. “The train wreck is the competing resources for two national needs: energy security and national security.”

In 2009, about 9,000 megawatts of proposed wind projects were abandoned or delayed because of radar concerns raised by the military and the Federal Aviation Administration, according to a member survey by the American Wind Energy Association. That is nearly as much as the amount of wind capacity that was actually built in the same year, the trade group says.

The Defense Department is concerned that turbine blades are indistinguishable from airplanes on radar systems, and they can even cause blackout zones so that planes disappear from radar.  Additionally, clusters of turbines can look like storm activity on weather radar.  For all of these reasons, some argue that wind turbines pose a risk to training, testing and national security in some regions.