Governors' Wind Energy Coalition

A new computer model devised by federal researchers could help wind-power developers better forecast possible bird fatality problems at wind farms nationwide.

Researchers with the U.S. Geological Survey and Fish and Wildlife Service said today that the computer model has been designed to allow developers, policymakers and ecologists to predict the number of deaths at proposed wind farms before they’re built and placed into operation.

The model, outlined in a study out this month in the journal PLOS ONE, uses pre-construction monitoring data on three parameters — hazardous footprint, bird exposure to turbines and collision probability — to make the calculations.

“This simplicity is part of what makes the model accessible to others,” said Leslie New, an assistant professor of statistics at Washington State University who led the research project as a USGS postdoctoral fellow. “It also allows wind facility developers to consider ways to reduce bird fatalities without having to collect a complicated set of data.”

The impact of the growing renewable energy industry, particularly large-scale wind power development, on eagles has been a source of controversy for several years.

The Fish and Wildlife Service drew the ire of conservationists in 2013 when it moved to allow wind farms and other industrial developments to apply for 30-year incidental take permits for eagles, which are protected under the Bald and Golden Eagle Protection Act. The American Bird Conservancy has filed a federal lawsuit challenging the eagle-take rule.

Fish and Wildlife in February announced it is considering establishing a permitting system that would allow the legal, unintentional killing of the more than 1,000 bird species protected under the Migratory Bird Treaty Act.

The wind energy industry has been working to better position projects in areas with lower bird impacts and to incorporate operational changes that reduce bird deaths.

The researchers used golden eagles to test the model because they are susceptible to collisions with wind turbines, in part because of their soaring and hunting behavior, according to the study.

The Fish and Wildlife Service has developed a permitting process for wind projects requiring that predictions be made in advance of a wind farm’s construction. The new computer model was developed specifically for the purpose of assessing bird deaths as part of the preconstruction permitting process, according to USGS.

The researchers used as a case study a 110-turbine wind-power facility in Converse County, Wyo., both before and after construction in 2010. They estimated the wind farm operation would result in 4.8 eagle deaths a year.

“We have constructed a straightforward collision risk model that directly incorporates uncertainty and can readily be adapted as information becomes available,” according to the study.

The latest computer model drew faint praise from the American Bird Conservancy.

“We certainly do need better models to assess the potential impact of wind energy projects on birds and bats. The hundreds of thousands of birds and bats being lost annually to wind energy development is not acceptable, especially when it involves threatened or endangered species,” said Michael Hutchins, director of ABC’s Bird Smart Wind Energy Campaign, in an email.

“While ABC applauds such efforts, they must also be taken with a grain of salt,” he added. “As long as mortality data are based on industry self-reporting, which is a direct conflict of interest, there will always be a question about the accuracy of the models being used.”