Environmental Benefits and Concerns
Development of renewable energy resources is essential to address national energy needs and reduce the effects of climate change associated with the burning of fossil fuels. However, weighed against these needs are concerns regarding potential risks to birds and other living resources.
Avian and other wildlife risks associated with wind farms should be evaluated and addressed in terms of population level effects, taking into account particularly vulnerable species as well as cumulative effects of wind industry developments. Improved models need to be developed to better predict population effects of both individual projects and cumulative impacts of the industry as a whole.
Wind energy facility impacts on birds may include disturbance, displacement, barriers to movement, collision, and habitat loss. Such impacts need to be adequately evaluated and unsustainable population level impacts avoided. The scientific understanding of avian risks associated with wind farms is still evolving, and the precise level of risk to bird populations for any particular project is difficult to predict. Such risks are site-specific, and are also affected by the design, size, number, array, and lighting of wind towers. As wind energy technology has developed, the trend has been toward larger, taller towers and larger arrays of many towers in one location. The risk of avian impacts at wind farms are likely increased where large-scale facilities are proposed in areas frequented by concentrations of birds or along key migratory pathways.
The overall analysis of risks to birds from wind towers must be weighed against the negative environmental consequences of traditional energy sources such as fossil fuel burning facilities that have well-documented detrimental effects on birds, their habitats, other wildlife and natural resources, and human health.
Aviation warning lights also pose a risk to birds and must be carefully evaluated. The Federal Aviation Administration (FAA) requires lights on structures of 200 feet or more. The new generation of wind turbines usually require lighting. Many migratory birds such as warblers and thrushes migrate at night and are attracted to lights, especially during inclement weather. At such times, these nocturnal migrants can become disoriented and strike tall structures on which lights are mounted. Millions of birds die each year in collisions with tall buildings, communications towers, and other structures. Due to concerns regarding cumulative impacts on bird populations, the U.S. Fish and Wildlife Service (USFWS) and bird conservation groups are examining this issue at the national level. Migratory birds are protected by federal law, and endangered species are further protected by federal and state endangered species laws. Although the USFWS has enforcement powers over facilities that cause bird deaths, there is no proactive permitting system to avoid and minimize bird collision hazards associated with wind turbines or other tall structures. The USFWS, FAA, and Federal Communications Commission have not reached consensus on solutions that would protect birds while simultaneously meeting the nation's communications and aviation safety needs. As the wind energy industry expands, the need for national standards to address these concerns becomes ever more urgent.
Wind farms may also affect other wildlife due to direct alterations of habitat or by displacing or attracting certain species. Land-based wind farms developed in previously remote areas may require construction of new access roads with associated direct and indirect impacts to land and water resources. Wind turbines erected in the ocean may affect marine life as well as birds. In addition, potential conflicts with traditional commercial and recreational uses such as fishing and boating need to be considered in planning and permitting offshore wind energy projects.