Birds & wind energy
No energy source – or really, any human activity, for that matter - is completely free of environmental impacts. But, as a non-polluting energy source, wind energy is one of the most environmentally benign ways to generate electricity and is far less harmful to wildlife than energy sources it displaces – including to birds, and their critical habitats. Wind is one of the only energy sources without population-level impacts, such as climate change-related habitat loss.
Even with its relatively low impacts, the wind energy industry is held to a higher standard and does more to study, avoid, minimize and mitigate any wildlife impacts than any other energy industry. Resulting conservation efforts by wind developers save habitat and help protect wildlife.
Bird collisions with wind turbines are a small fraction of causes of avian mortality
The number of birds that are impacted as a result of collisions with wind turbines will never be more than an extremely small fraction of human-related avian fatalities. Only about 2.8 birds per wind-powered megawatt are lost annually as a result of U.S wind energy generation. That’s less than 200,000 birds per year based on current installed wind capacity, according to the most recent analysis of data from 109 post-construction studies performed at 71 facilities across the United States.
In fact, less than three in 100,000 (i.e., .0003%) of human-caused bird fatalities are attributed to wind energy, according to a 2007 National Academy of Sciences study.
Significantly greater causes of bird mortality
To put the wind energy impacts into perspective, other causes of avian mortality are significantly greater. These other causes of avian mortality include:
- Collisions with buildings, which is estimated to kill 97 to 976 million birds annually;
- Collisions with high-tension lines, which kills at least 130 million birds annually;
- Collisions with communications towers, which kills between 4 and 5 million (based on “conservative estimates”), but could be as high as 50 million birds annually;
- Cars, which may kill 80 million birds annually
- Environmental toxins including pesticides, which kill more than 72 million birds annually; and
- Domestic cats, which historically have been estimated to kill hundreds of millions of songbirds and other species annually (although a more recent study indicates that perhaps this could exceed one billion).
Other energy sources pose greater risks to birds than wind
Wind power poses “no population-level risks to birds,” according to a 2009 comparative analysis of the impact of six electricity generation types on wildlife. After considering the effects of pollution and climate change, that study concluded that “non-renewable electricity generation sources, such as coal and oil, pose higher risks to wildlife than renewable electricity generation sources, such as hydro and wind.”