14 DAY TRIAL // A new paper authored by researchers working with the Smithsonian Institution Migratory Bird Center, the US Fish and Wildlife Service and the Oklahoma State University documents how the wind power industry in the United States affects the country's biodiversity, especially its bird population.
In their paper, the researchers argue that, according to evidence at hand, monopole turbines now up and running across the US kill an average of 140,000 to 328,000 birds on a yearly basis.
Interestingly enough, it appears that there is a correlation between how tall a monopole wind turbine is and how many birds it kills annually.
Earth Techling says that, according to these researchers, the taller a turbine is and the longer its blades are, the more birds are hit by it throughout the course of an entire year.
Specifically, it appears that turbines that measure about 36 meters (118 feet) in height kill an average of 0.64 birds per year. Turbines that stand 80 meters (262.5 feet) tall, on the other hand, are to blame for the death of 6.20 birds annually.
“As turbines get taller, greater mortality may occur due to turbines extending further into altitudes that contain large numbers of flying birds,” the specialists write in their paper.
Furthermore, “As rotor diameter increases, a greater area of airspace is swept by the turbine blade and therefore exposed to collision risk.”
Then again, tall wind turbines are known to have a greater output than shorter ones, so their individual impact on the US' bird population could be mitigated by the simple fact that fewer of them would have to be installed in order to produce a given amount of electricity.