LIVERMORE, Calif. — Although wind power has been promoted as kind to the environment, giant wind turbines that generate electricity are proving fatal to golden eagles and other birds.
As many as 567 eagles, hawks and other birds of prey were killed by turbine blades and electrical wires during the last two years in the Altamont Pass area near Livermore, the California Energy Commission said.
With 7,000 turbines, the 80-acre area has the world's highest concentration of electricity-generating windmills.
A commission study recommends several measures, including painting the turbine blades to make them more visible, installing noise-producing devices to warn birds away, and reducing the number of rodents and other small animals the birds eat.
The third option will prove the most effective way to keep the birds away from the turbines, but cattle ranchers--on whose land the turbines stand--won't like it, said Alameda County planner Darryl Gray.
Letting vegetation grow near the turbines will keep ground squirrels away, and fencing groups of windmills would keep cattle from eating the vegetation, Gray said. But that would eliminate some grazing land.
The turbines now take 3% to 5% of the area's grazing land out of service, but fencing turbines would double those figures, Gray said.
David Nesmith of the San Francisco Bay Area chapter of the Sierra Club said the solution should not be chasing the birds away by eliminating the animals they eat.
"Raptors and wind-generating facilities occupy the same ecological niche," he said. "We have to figure out ways for them to coexist."
About half the bird deaths were attributed to collisions with turbines, 11% from collisions with power lines and 8% to electrocution. The causes of the other deaths were not known.
A consulting firm will carry out the recommended experiments under another phase of the study.