Wind energy is crucial to battling climate change. Can it expand without harming eagles? 

Hot air rises off the Mojave Desert like devil’s breath. Sage-scented and sandy, it lofts to collide with cool gusts sliding down the granite slopes of the Sierra Nevada. This is the realm of golden eagles, drawn for millennia by these swirling winds to hunt, sky-dance and execute their spectacular courtship rituals. They are kings of the currents that sweep over the barren landscape of the Tehachapi region 120 miles northeast of Los Angeles. 

Today golden eagles share the air with an increasing number of wind turbines spinning clean, nonpolluting energy. Here, where the U.S. wind industry was born, thousands of blade-topped towers punctuate the land in a dizzying array that ranges from diminutive 75-foot structures to behemoths reaching 650 feet into the air. With more than 300 next-generation turbines in various stages of planning, the Tehachapi is one of the nation’s fastest-growing renewable energy areas. Soon it will expand its production from 4,500 megawatts of power to more than 6,000 megawatts.

But even clean energy comes at a price. The impact of wind energy on birds and bats is well documented although the numbers are uncertain. When it comes to bald and golden eagles, a study released by federal biologists in September found that since 2008, wind farms in 10 states have killed at least 67—a number the researchers say is likely a significant underestimate because of the lack of rigorous monitoring and mortality reporting. In addition, population levels of golden eagles are not well known, and in desert areas where there are fewer birds, conservationists say even a small number of fatalities could be a significant problem.

For these consummate hunters, habitat loss is in the 500 feet of airspace above the ground where they court, compete and forage. The higher the wind turbines, the more they encroach, says Pete Bloom, a raptor specialist. While scientists are still learning about eagles’ patterns and behavior, they know wind energy is affecting both resident and migrating birds. 

This collision of bird and blade presents a conservation conundrum:  how to create renewable electricity—enough to meet society’s expanding needs—without harming irreplaceable wildlife. As scientists and citizens across the country grapple with this challenge, the Tehachapi is one of a handful of places quietly pursuing solutions. Conservationists, industry and agency officials are working together to site wind turbines to minimize their impact and develop technology and policies that protect wildlife. 

“It’s not about either/or,” says Julie Falkner, Defenders of Wildlife’s senior director for renewable energy. “We must simultaneously achieve renewable energy goals and preserve species and habitat. To do this, we need strong, effective siting and management tools.” 

Along the back roads of Kern County west of the dusty town of Mojave, gigantic structures hulk across hillside after hillside, their arms spinning out of sync against a pale spring sky. These humble slopes, still dotted with farm houses and barns, have been transformed into a surreal, transfixing panorama almost twitching with energy. It’s no surprise the wind industry has a strong hold here. When Stephanie Dashiell, a Defenders’ biologist, cracks a car door slightly she has to hold on with both hands to keep it from ripping out of its hinges. Tehachapi wind speeds average 20 miles per hour and often peak at over 50 miles per hour.

There weren’t any guidelines in those pioneering days of the early 1980s, when lightly cultivated lands began filling with turbines. Most were 45- to 60-foot structures that produced 25 to 60 kilowatts of electricity. Today’s turbines tower over these early experiments, rising from concrete pads built among Joshua trees and cholla cacti scattered across the dusty ground. Dashiell peers upward, trying to grasp just how immense these newer turbines are. The boxes atop the towers, filled with gears, shafts, brakes and generators, are the size of large motor homes. The highest towers rise 100 feet higher than the Statue of Liberty’s torch, and each rotating blade can extend another 180 feet into the air. 

Wind energy production in the Tehachapi started tentatively but surged in 2006, when California enacted a law requiring the state to reduce its greenhouse gas emissions to 1990 levels by 2020. By the time the 2009 American Recovery and Reinvestment Act offered financial incentives to alternative energy developers, wind prospectors were tromping through these rugged hills wooing ranch owners with promises of big bucks for harnessing the breezes blowing across their lands. 

Among the courted was the Cattani family, whose ranch is in the remote center of sprawling Kern County. County officials were so enthusiastic about the potential for wind development they approved a resolution calling for 15,000 megawatts of production by 2030 and began issuing permits. Their map identifying potential sites was the alarm that got the family’s attention. “We felt like it put a great big bull’s eye on us—on the entire Tehachapi Mountains,” says Emmy Cattani, a rancher who serves on the Tejon Ranch Conservancy board. 

She and others formed the Tehachapi Working Group to identify environmentally sensitive areas as well as places where they believed energy development would be appropriate. Working closely with their county supervisor, they developed a map that won approval from the Kern County Planning Department. It wasn’t perfect, Cattani says, but it protected the most vulnerable areas and respected the Tehachapi vista. The Board of Supervisors’ vote late in 2012 rejected the map, but the process put wind developers on notice: “Here’s where we are going to work with you and here’s where we are going to encourage you not to go even if it’s not official policy,” Cattani says.

Despite stopping short of approving areas off-limits to turbines, Kern County’s “no-go” map is a step in the right direction, says Dashiell, who specializes in renewable energy issues. The Bakersfield office of the Bureau of Land Management, which issues permits to wind developers on its federal lands, recently recognized the importance of considering impacts on a landscape scale. Instead of a piecemeal approach, its resource-management plan identifies development avoidance areas across 17 million acres.

Dashiell is working with state officials on the Desert Renewable Energy Conservation Plan (DRECP), which encompasses 22.5 million acres in private and public lands in southern California’s desert region. This multi-agency planning effort, a major component of the state’s renewable energy program, is designed to protect desert ecosystems while allowing for energy development. The goal is to minimize bird fatalities by guiding wind developers to areas already degraded or less important to golden eagles and other birds, a concept Defenders calls “smart from the start.” The predictability that comes with knowing where a wind farm can and cannot be sited helps drive down the costs, says Peter Kelley, a spokesman for the American Wind Energy Industry. Defenders supports the concept guiding the development of the DRECP, expected in draft form this spring, and is working toward its success.

As the industry matures, improvements in technology are contributing to these efforts to reduce bird impacts. The blades of the new, larger turbines don’t whirl at the same frantic speed, says Shawn Smallwood, an independent ecologist who studies raptor behavior at wind farms. They also generate much more electricity than older models, allowing one new turbine to replace several old ones in a swapping-out process called “repowering.” That procedure has been underway at Altamont Pass, 50 miles east of San Francisco, since 2006, when several Audubon chapters settled a lawsuit that gave wind companies until November 2009 to cut bird deaths by 50 percent.  NextEra Energy Resources, one of several companies with turbines at Altamont, has so far removed 800 of the old machines, replacing them with 34 newer models. The new sites, based on Smallwood’s and other scientific studies, are aimed at places less appealing for golden eagles and other raptors. Moving turbines away from the front of ridge tops where kestrels like to hover, for example, will kill fewer of them, says Smallwood.

Operators at Altamont are also shutting down wind turbines for several months in the winter when California power demands drop. The combined results, reported in a study released last January, document a 50 percent drop in bird mortality since 2005. The consultants later retracted that finding but Smallwood and others acknowledge that the changes at Altamont have reduced the number of birds killed by wind turbines. “I don’t want to sound giddy but we’re definitely heading in the right direction,” says Michael Lynes, executive director of Golden Gate Audubon, one of the chapters involved in the 2006 lawsuit.

Other technological innovations involve experiments with radar systems that detect approaching birds. Some projects have biologists on site to identify the species and, when appropriate, turn the turbines off. Other turbines shut off automatically. One of the more promising systems is designed to detect incoming endangered California condors. Around 70 percent of these federally protected birds carry VHF transmitters on their wings, emitting a signal that can be detected 16 miles away. When wind farms pick up the signal, the operators can send someone to confirm a condor siting and turn the turbines off. That won’t work for golden eagles, says Bloom, because few carry VHF transmitters. 

Wind energy innovators are also designing new turbines, including a small vertical-axis construction arranged to optimize efficiency by having each turbine boost the power output of its neighbors. Smallwood is enthusiastic about the potential for turbines covered by a fiber shroud, which allows birds and bats to see the entire rotor display and protects them from the spinning blades. The value of these inventions has not been proved, and many raptor specialists are skeptical about their overall effectiveness. Still, they acknowledge the effort toward reducing avian mortality. “There are thoughtful developers out there and we support them,” says Garry George, Audubon California’s renewable energy director.

Despite these efforts, birds across the country continue to die. Killing eagles is not just a tragic loss to a species. It’s a federal crime. The Bald and Golden Eagle Protection Act prohibits the “taking” of a single bird. Dashiell would like to see more guidelines requiring third-party monitoring of bird mortality. Designing and implementing a comprehensive, effective permitting program is also key to changing the way the wind industry impacts eagles. The U.S. Fish and Wildlife Service (FWS) does require developers to minimize their impacts on federally protected species, like eagles, through the issue of “incidental take” permits. Projects where federal biologists are involved generally result in fewer deaths, says Dashiell. But recently, FWS finalized a new rule that extends the length of a take permit from the current five years to up to 30 years. 

This is troubling for the conservation community. While long-term permits are clearly a win for developers and alternative energy, only time will tell if they will also help sustain eagles and other species, says Defenders’ President Jamie Rappaport Clark. “Without fully knowing the long-term biological consequences for eagles, FWS must proceed cautiously, closely monitor progress and ensure strict compliance.”

Meanwhile, the wind industry is poised to expand exponentially—from the current 60,000 megawatts of capacity to 300,000 by 2030. Some estimates indicate that this growth will avoid 100 million tons of carbon dioxide emissions, a reduction critical to mitigating climate change. Defenders is working to ensure that wind energy develops with more vigilance than traditional energy sources did. “As we seek to protect species and help them adapt to the long-term impacts of climate change, we must also deal with the immediate impacts caused by new energy sources.  For golden eagles, this is critical,” says Falkner.

Dashiell is hopeful that collaboration and proactive planning in the Tehachapi region will provide a model for state and federal agencies here and elsewhere. It’s an opportunity to protect ecosystems without jeopardizing clean, renewable energy. “We don’t want to repeat the mistakes of other energy sectors,” she says.

At dusk on the edge of the Mojave Desert, a jack rabbit hops among the creosote brush, avoiding the paved roads and ignoring the erratic hum of the whirling turbines silhouetted against a fading salmon sky. Some desert species are unaffected by the changes renewable energy is bringing to their habitat. For golden eagles and other more sensitive wildlife, the future is less certain.  

California-based writer Jane Braxton Little had to hold onto her hat—and her notebook—while reporting this story. 

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