GROVER, Colo. – From a mile away, the sleek rows of wind turbines turn lazily in the stiff morning breeze, the rising sun glinting off their shiny fiberglass blades.
Their size – many turbines tower 300 feet above the ground – only becomes apparent from up close, as the tips of the knife-edged blades spanning nearly an acre slice the air at 200 mph.
Utility companies installed thousands of new turbines last year and are on track to install even more this year, generating pollution-free electricity whenever the wind blows. But even as the turbines help utilities reduce carbon emissions and pollution, they’re causing a new problem: Those churning blades kill hundreds of thousands of birds annually, including federally protected golden eagles.
“It’s really kind of discouraging right now,” said Brian Rutledge, executive director of Audubon Wyoming.
Now, federal wildlife officials are cracking down on wind farms caught killing bats and birds. A peer-reviewed study issued last summer estimated turbines kill as many as 368,000 birds annually.
Underlying much of the bird-death debate is concern about carbon emissions and other pollution caused by traditional power sources. Scientists say a changing climate will ultimately kill far more birds and bats than wind farms, making pollution-free energy all the more important.
Context is also important. House cats kill at least 1.4 billion birds annually, and possibly up to 3.7 billion birds, according to a 2013 federal study. And a single natural-gas flare at a liquid natural gas plant in Canada killed an estimated 7,500 birds in a single night.
Wind farms, however, get special attention because they’re new. Berkshire Hathaway, for instance, is building a $1.9 billion wind farm in Iowa that will provide power for companies such as Google, Facebook, Amazon, Yahoo and Microsoft, which have committed to buying wind-generated electricity.
Last year alone, utilities installed about 2,500 turbines across the country, most of them in Iowa, Michigan, Nebraska, Oklahoma and Texas. California, Colorado and Wyoming are also home to large wind farms.
Wind farms are heralded as inexpensive pollution-free sources of electricity, turning the air’s movement into power that can be transmitted around the country to light homes, run air conditioners and keep TVs on.
Wind-industry experts say turbines are being held to a far higher standard than traditional energy producers, such as coal mines and power plants, or natural-gas drilling sites.
“Most wind farms have never taken an eagle and never will,” said John M. Anderson, director of permitting policy and environmental affairs for the American Wind Energy Association. “It’s important to remember that we have a power-hungry society – and the energy has to come from somewhere. No form of energy generation is free from impact.”
In late December, Oregon-based utility PacifiCorp Energy pleaded guilty in U.S. District Court in Wyoming to violating the federal Migratory Bird Treaty Act after federal investigators discovered the carcasses of 38 golden eagles and 336 other protected birds, including hawks, blackbirds, larks, wrens and sparrows at two PacifiCorp wind projects starting in 2009.
The utility agreed to pay $2.5 million in fines and restitution, with much of the money going toward mitigation efforts designed to reduce bird deaths. Federal officials say the company built the two wind farms while ignoring recommendations from federal wildlife officials.
Wind farms are generally approved at the local or county level, which means federal officials have little power to control their construction or location. Instead, officials with the U.S. Fish and Wildlife Service offer recommendations and then seek fines and court orders for utilities that get caught killing birds. Wildlife service officials say they prioritize their enforcement toward utilities that ignore the guidelines, as PacifiCorp did.
Fish and Wildlife Service director Daniel Ashe said existing wind farms can reduce bird deaths by altering when the turbines are turning, such as during migration season, by waiting until the winds are stronger, when fewer birds or bats are flying, and by making nearby power lines less attractive as perches.
He said most utilities have been good partners in figuring out where to build wind farms where they’ll cause the least damage. Even the type of tower holding up the turbine and generator makes a difference: lattice-style towers of the kind first used by the Altamont Pass wind farm east of San Francisco are more attractive places for birds to land than the smooth white towers usually built now.
“Overall, the wind industry has been a very willing and good partner. But they’ll make mistakes. It’s no different than any other industry,” said Ashe. “We will go after bad actors and make sure that people know that if they do everything they can do … then they don’t have anything to worry about. But if they are a bad actor, there will be a consequence.”