Siting and Wildlife: Frequently Asked Questions
When compared to traditional energy sources, clean, fuel-free wind energy offers compelling advantages: it produces no emissions, stabilizes energy prices, and provides abundant electricity for our escalating needs. Like all human activities, wind energy has an impact on the surrounding environment, but our society, even with increased energy efficiency, demands a steadily growing amount of electricity.
Q: What direct impacts does wind have on wildlife?
Q: What impacts does wind energy development have on land use and wildlife habitat?
Q: What is the industry’s position on impacts of wind energy development on wildlife?
Q: What is the wind industry’s commitment to wildlife protection?
Q: What is the Altamont Pass? Are impacts at this project site typical?
Q: Are certain turbine designs safer than others?
Q: How does wind compare to other energy sources in terms of its impact on wildlife?
Q: What direct impacts does wind have on wildlife?
A: Wind, a 100% clean energy source, is one of the healthiest energy options, and one of the most compatible with animals and humans. The wind industry is committed to reducing their impact of wind turbines on wildlife, specifically birds and bats.
Modern wind power plants are collectively far less harmful to birds than radio towers, tall buildings, airplanes, vehicles and numerous other manmade objects. Bird deaths due to wind development will always be a very small fraction of those caused by other commonly-accepted human activities, no matter how extensively wind is used in the future.
Avian studies have been performed at many wind farm sites. They show that bird kills per megawatt (MW) average one to six per year or less, except at a single three-turbine plant in Tennessee that records 11 per MW per year. On the other hand, some wind farm sites experience no bird kills.
A reasonable, conservative estimate is that of every 10,000 human-related bird deaths in the U.S. today, wind plants cause less than one. The National Academy of Sciences estimated in 2006 that wind energy is responsible for less than 0.003% of (3 of every 100,000) bird deaths caused by human (and feline) activities.
A paper from the National Wind Coordinating Collaborative (NWCC) found the leading human-related causes of bird kills in the U.S. include:
- Cats (1 billion per year)
- Buildings (100 million to 1 billion per year)
- Hunters (100 million per year)
- Vehicles (60 million to 80 million per year)
- Communications Towers (10 million to 40 million per year)
- Pesticides (67 million per year)
- Power Lines (10,000 to 174 million per year)
Q: What impacts does wind energy development have on land use and wildlife habitat?
A: All fuel extraction and energy generation activities affect habitat and land use. Mining, drilling, fuel transportation and waste treatment for fossil fuels are all land-intensive activities, while pollution from fossil fuel combustion affects broad geographic areas. A wind energy project is also land-intensive, but the land is used quite differently. The “fuel extraction” and electricity generation take place at the same site each year. Wind projects occupy anywhere from 28 to 83 acres per megawatt depending on local terrain, but only 2 to 5 percent of the project area is needed for turbine foundations, roads or other infrastructure.
Habitat fragmentation occurs at projects in relatively pristine areas due to tree removal around turbines; also, new “edges” created in a forest (when parts of it are cleared for turbines or service roads) are detrimental to some species, and certain animals avoid previously viable habitats due to the presence of turbines. The wind energy industry is partnering with conservation groups and government agencies to avoid, minimize and mitigate these impacts where possible.
Q: What is the industry’s position on impacts of wind energy development on wildlife?
A: The wind energy industry has worked hard since the early 1990s to reduce the impact of wind turbines on birds. Those efforts have been very successful; wind turbines and birds coexist successfully at many locations. The wind industry is now beginning a similar effort to understand and reduce the regional impact of wind turbines on bats where problems have arisen.
Individual bird deaths due to wind development will always be a very small fraction of those caused by other commonly accepted human activities and structures, as mentioned above..
New wind projects are carefully planned to minimize environmental impact, even though wind is already one of the cleanest, most environmentally friendly energy sources because it emits no air or water pollutants or greenhouse gases, requires no mining or drilling for fuel, and produces no toxic waste.
The wind industry welcomes scrutiny of, and comparison with, all of the impacts of other sources of power generation. Extensive studies of wind farm bird collisions have been completed, but very little efforts have been made to monitor direct impacts on avian species by mining and drilling, power plant emissions and pollution, or habitat loss.
Any public or private research effort, regulatory effort, or legislative proposal designed to quantify the impact of power generation on birds, bats, and other wildlife should encompass all power sources, not just wind.
Q: What is the wind industry’s commitment to wildlife protection?
A: The wind industry has implemented many practices leading to greater protection of the environment and wildlife. Below are just a few examples:
- The industry has been conducting avian studies at wind sites across the country for over 20 years. Pre-construction wildlife surveys are common practice throughout the industry. Typically a wildlife consultant is retained, and efforts are made to contact state and federal fish and wildlife agencies and local wildlife groups (e.g., Audubon chapters, Izaak Walton League chapters) to identify any possible issues. The consultant examines the proposed site and prepares a detailed impacts report for review by the developer. These surveys greatly reduce the threat to birds.
- Post-construction monitoring of bird kills at wind sites in variety of locations (Vansycle Ridge, Oregon; Ponnequin, Colorado; Foote Creek Rim, Wyoming; Buffalo Ridge, Minnesota; Searsburg, Vermont; Garrett, Pennsylvania) has validated the industry’s ability to assess risk to birds and build safe projects.
- Even sites with high use by protected species do not need to be off limits to wind power plants. At Foote Creek Rim in Wyoming, pre-construction surveys found that golden eagles frequently used the mesa’s edge for hunting. The wind farm developer voluntarily redesigned the site to move the planned turbines 50 meters away from the rim, and the subsequent number of eagle deaths at the site was so small that the technical advisory committee was discontinued. Studies about Foote Creek Rim can be found here.
- The frequency of bat deaths at a newly-constructed wind farm in West Virginia in 2003—far higher than at wind plants elsewhere in the U.S.-- caused concern, and subsequent studies at some other locations indicated that bat collisions are a problem. In response, AWEA and several of its member companies entered into a three-year cooperative effort with Bat Conservation International, the National Renewable Energy Laboratory, and the U.S. Fish and Wildlife Service to research wind/bat interaction and test ways to reduce bat mortality.
- AWEA produces a Siting Handbook that is free to download. This Web-based document describes the regulatory framework governing wind energy projects, and includes extensive technical discussions about the local impacts at wind project sites, how they can be studied and how they can be mitigated.
Q: What is the Altamont Pass? Are impacts at this project site typical?
A: The Altamont Pass was one of the first wind projects installed, and it remains the only wind development area in the U.S. that experiences significant bird deaths, specifically raptors or birds of prey (with "significant" defined as deaths that are numerous enough to possibly impact local populations of those species). While the industry recognizes that this situation is a problem, it is largely limited to this one area. Unfortunately, media coverage about Altamont Pass often gives the impression that all wind power projects significantly affect birds, despite overwhelming evidence to the contrary.
The Altamont Pass is unique. No other wind project combines a similar topography, very high raptor population, and old turbine technologies. Bird mortality, especially raptor mortality, at other wind sites is quite low, so most management techniques employed at Altamont are not likely to be applicable elsewhere.
Wind businesses have implemented many strategies to reduce bird collisions at Altamont. Over the years, wind companies have painted wind turbine rotor blades, reduced rodent populations, added "perch guards" to prevent perching on turbine towers, and tested raptors’ hearing, vision and avoidance capabilities to learn how to reduce bird impacts.
One particularly successful strategy greatly reduced raptor electrocutions. Based on earlier research, project owners modified their equipment by insulating wires, covering some exposed electric components on poles, and relocating overhead power lines to protect raptors.
The industry continues to test new measures to reduce bird kills, and to utilize those that are successful.
Q: Are certain turbine designs safer than others?
A: Developers of innovative wind turbine designs often claim that they are “bird friendly” or safe for birds. However, these claims are never supported by avian mortality surveys and must be viewed with skepticism. Also, as the wind industry has grown, the cost of entry has escalated: to bring a new utility-scale turbine design to commercial production would cost hundreds of millions of dollars.
Utility-scale wind turbines for land-based wind farms come in various sizes, with rotor diameters ranging from about 50 to 90 meters, and with towers of roughly the same size. Wind turbines intended for residential or small business use are much smaller. Most have rotor diameters of 8 meters or less and would be mounted on towers of 40 meters in height or less.
There are two basic designs of wind electric turbines: vertical-axis and horizontal-axis (propeller-style) machines. Horizontal-axis wind turbines are most common today, constituting nearly all of the "utility-scale" (100 kW capacity and larger) turbines in the global market. This is not to say alternative turbine designs may not be more widespread in the future, but the economics of horizontal-axis machines in today’s market make substitutions difficult, if not impossible, for projects originally planned for horizontal-axis turbines.
Q: How does wind compare to other energy sources in terms of its impact on wildlife?
A: The list of the effects of other energy sources on wildlife and the environment is long and varied. For a glimpse of the environmental impacts of various electricity sources, see the chart below.
While wind plants and their construction have local impacts, the use of wind energy largely avoids these more far-reaching effects.
Please find AWEA’s fact sheet on Wind Energy and Wildlife here,
http://www.awea.org/pubs/factsheets/Wind_Energy_and_Wildlife_Mar09.pdf |
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