Efforts to promote and develop new forms of sustainable energy have pushed wind power to the forefront. However, this type of power comes with a cost — as it often interferes with birds' and bats' migration, killing hundreds of thousands of these winged species.

 

According to a new study from the University of Colorado Denver, more than 600,000 bats were killed by wind energy turbines in 2012. This has serious environmental repercussions as bats help pollinate crops and help control harmful insect pests.

 

The study, which analyzed data on the number of dead bats found at wind turbine sites, will be published this week in the journal BioScience.

 

Areas near the Appalachian Mountains like Buffalo, Tennessee and Mountaineer, West Virginia had the highest bat fatality rates. Little information is available on bat deaths at wind turbine facilities in the Rocky Mountain West or the Sierra Nevadas.

 

The bats are killed when they fly into the towering turbines which spin at up to 179 mph with blades that can stretch 130 feet. Earlier estimates of bat deaths ranged from 33,000 to 880,000.

 

There are 45 known bat species in the contiguous U.S. many of which have important economic impacts. Not only do they control flying insects like mosquitoes, they also pollinate commercial crops, flowers and various cacti.

 

Those suffering the most fatalities are the hoary bat, eastern bat and the silver-haired bat.

 

However, there ways to mitigate the killings. One is to have the turbines activated to spin at higher wind speeds when bats don’t tend to fly. In a recent study in Pennsylvania, researchers adjusted the operating speeds from 10 mph to 18 or 20 mph and decreased fatalities by 40 to 90 percent.