Wind energy represents a potential source of electricity that is renewable and non-fossil fuel based. In recent years, the growth of wind-energy capacity in the U.S. has been extremely rapid, increasing from 1,848 MW in 1998 to 31,109 MW in mid-2009. Over 27,000 MW of new wind energy generation capacity came on line worldwide in 2008, bringing the total global wind energy capacity to over 120,000 MW. A recent article in Science estimated that there is enough wind energy potential in China to meet that country’s projected demand for electricity in 2030, about twice their current consumption, with the potential to displace 23% of electricity generated from coal in China. Like all sources of energy exploited to date, wind energy has effects that displease at least some people. The killing of bats and birds has been among the more obvious and objectively quantifiable adverse effects. Birds can be electrocuted along transmission and distribution lines or killed by collisions with transmission lines and turbines. The Altamont facility in California, the oldest utility scale facility in the US, has caused the deaths of many birds, including federally protected species of raptors. In general, at modern facilities avian fatality rates appear similar in agricultural (2.9/MW/YR), grassland (2.7/MW/YR), and forested landscapes (3.3/MW/YR), although limited sample sizes make extrapolation subjective. Bat fatalities have ranged from approximately five to 50 bats per MW per year and are skewed toward migratory tree-roosting bats. Avian and bat collisions are not the only wildlife impact of concern. Habitat loss is a major concern for birds, primarily from behavioral avoidance and especially for prairie species. While several states and the US Fish and Wildlife Service created guidance on development of wind energy to minimize environmental impacts, there is a lack of uniform regulatory standards or frameworks for evaluating the environmental effects of wind-energy facilities.
Results/Conclusions
I describe a framework for pre-construction prediction and post-construction estimation of impact from wind energy development. The framework is loosely based on frameworks developed in several major environmental programs with mandates to assess the degree and magnitude of impacts to wildlife, including existing risk assessment frameworks developed and used by the Environmental Protection Agency (e.g., Superfund program). The framework provides a structure for focusing scientific principles and critical thinking toward the goal of effective environmental management.
