Wind turbines produce energy without polluting the environment. While driving on a flat piece of road in many states in the USA, wind farms can be seen for miles. The United States Department of Energy (DOE) has set a goal that by 2030, wind energy sources will produce 20 percent of the electricity needed in the United States. The goal also is to have wind energy facilities in almost every state (including Alaska and Hawaii). Currently there are approximately 50,000 wind turbines in operation in the USA which provide about 8 percent of the country’s energy-generated usage. The production of clean energy is sorely needed and welcomed, but with the solving of one problem another problem is sometime created. The good thing is the problem has been recognized and research is happening to find a solution.
With the use of wind turbines increasing, bird fatalities are increasing also. Experiments are being conducted to minimize them. One study that researched turbine lighting found no difference in the number of fatalities if the turbine was lit or unlit. The conclusion is that light has nothing to do with the fatalities. One down. The height of the turbines is also being studied. Raptors and some land birds that fly during the day hours, do so at a much lower altitude than previously thought. Thus, birds colliding with the blades. Newer turbines are taller in height than their predecessors. The blades are now in the “flight zone” of nocturnal migrating birds. Low turbines cause fatalities in the day hours; tall turbines cause fatalities at night. What is the answer? With continuing research, hopefully, the problem will be solved.
Another concern is the impact the turbines have on the bird’s habitat which it depends on for survival. Birds search for food in open habitats while in a soaring flight. When soaring, birds cannot maneuver well and are unable to avoid collision with the turbine’s blades. Before this problem was identified, turbines were located in open areas. Studies to identify bird habitats are being done to avoid siting turbines in their areas.
Wind turbines are also the enemy of bats. Bat fatalities are caused when the bat collides with the blades. Barotrauma involves tissue damage to air-containing structures (like lungs) caused by rapid or excessive pressure change. Near the edges of the blades, air pressure changes. This has been attributed as a cause for some of the fatalities. Research has found that many bat species can be spared if the blades are prevented from spinning in low-wind conditions. Another research group is working on using an ultrasonic acoustic deterrent. They hope it will cause bats to avoid this loud sound that the bats can hear, but humans cannot. The sound would be emitted from the turbine.
As the turbine industry continues to learn more about how birds move across the landscape, may they be successful in designing and placing turbines so we can have an abundance of clean energy and our loved flying creatures (birds and bats) can be safe.