This is an excerpt from EERE Network News, a weekly electronic newsletter.

August 18, 2004

Altamont Pass Research May Lead to Reduced Bird Deaths

Photo of wind turbines at Altamont Pass.

California's Altamont Pass
Photo credit: Ed Linton

Plans to expand wind production in California's Altamont Pass have been on hold while researchers study ways to reduce bird collisions with turbines. The results of a four-year study the California Energy Commission (CEC) released on August 10 predict that several measures could reduce bird deaths by up to 50 percent for some species at Altamont Pass. The study, done by a private consultant, estimates that 1,766 to 4,721 birds, of which 881 to 1300 are protected raptors, are killed annually at Altamont Pass, the world's largest wind farm region. Researchers studied bird behaviors, raptor prey species availability, wind turbine and tower design and location, landscape attributes, and range management practices. The goal was to develop models that could be used to predict high-collision risk situations. Researchers concluded the most effective solution to reducing bird collisions in the area is to replace the numerous small existing turbines with fewer larger turbines on taller towers. The newer turbines are more efficient, with one turbine generating the same capacity as seven to ten older ones.

Other recommendations include: relocating selected highly dangerous turbines; removing broken and non-operating turbines; installing structures at the ends of turbine strings to divert birds around the turbines; and developing management practices, other than poisoning, to control rodents—food sources for birds—that may congregate around the base of turbines. See the CEC press release or go directly to the 520-page report, "Developing Methods to Reduce Bird Mortality in the Altamont Pass Wind Resource Area." (PDF 84 MB). Download Acrobat Reader.