San Francisco-based developer Pattern Energy has devised a program that combines cutting-edge technology with a human element in order to mitigate a California wind farm's potential impact on golden eagles.
As part of its pre-construction monitoring studies for the 315 MW Ocotillo Wind Energy Facility, Pattern's eagle mitigation program requires that a certified biologist perched on a 50-foot observation tower – with high-powered binoculars in hand – scan the area for signs of golden eagles.
Pattern's $6 million program also involves outfitting the observation tower with an advanced radar system that scans the atmosphere and records the activity. If a golden eagle were to come close to the wind farm, the biologist would record the activity and initiate curtailment.
The biologist, who will remain on-site once the wind farm achieves commercial operation, can communicate curtailment orders to Ocotillo's on-site operations center or to Pattern's Houston-based remote command center, which monitors the company's generating assets.
Although the wind industry has worked hard to mitigate the impacts of wind farms on avian species, the golden eagle, in particular, has been affected in recent years.
Golden eagles receive federal protection under the Bald and Golden Eagle Protection Act (BGEPA). The law prohibits the taking of eagles, including killing, harassing, molesting or disturbing them or their nests. Concerns over civil and criminal liability under BGEPA have proven to be significant obstacles to the development of wind farms and have resulted in numerous stalled or canceled projects.
Of the estimated 30,000 golden eagles in the U.S., nearly two-thirds reside in the western U.S.
The presence of golden eagles at California's Altamont Pass – which uses the now-outdated lattice-style wind towers as perches – has long presented significant challenges for wind farm owners and operators.
‘We have taken a progressive view [to eagle mitigation],’ John Calaway, Pattern Energy's director of development, tells NAW. ‘We have been working at this for several years. The industry is still in a transition period with eagle mitigation. What we're doing is taking extra precautions to mitigate any impacts.’
Although the golden eagle is less likely to frequent Pattern's Ocotillo site than the Altamont Pass, it is still a good location to test the program's proof of concept, Calaway says. However, he admits Pattern's approach may not work for everyone.
‘Developers with smaller projects may not be able to afford this solution, but we think it's a more surgical approach to eagle mitigation,’ he notes. "If the testing proves successful, Pattern will use the program in other site locations."
The company's eagle mitigation plan will remain in place after the Ocotillo project achieves commercial operation, which is expected by the end of this year.