A Vermont wind project is applying for the first-ever Endangered and Threatened Species Taking Permit for bats from the Agency of Natural Resources.
Sheffield Wind, whose 16-turbine, 40-megawatt utility scale project in the Northeast Kingdom went on line last fall, has filed for the permit because a fungus has decimated Vermont bat populations and placed them on the endangered or threatened species list. “White-nose syndrome” has caused mortality of more than 90 percent of the population of little brown and long-eared bats in the state.
Based on national studies, the rotating blades of wind turbines can pose a threat to bats and any “taking” of endangered species requires a permit from the secretary of the Agency of Natural Resources.
“This is the first time it’s come up as I understand,” said ANR Secretary Deb Markowitz, who said she has been briefed by her staff on the permit request and will likely issue her decision before the end of August.
Markowitz said she anticipated other wind projects in the pipeline, such as Kingdom Community Wind, a controversial 21-turbine, 63 megawatt project being built in Lowell by Green Mountain Power, will also be required to file a bat taking permit as well.
Markowitz said the permit involves an interesting “cross-section of law, science and policy.” She explained that her options in issuing the permit involve actions such as calling for a variety of operational curbs to mitigate any impact on bats and requesting studies, though she does have the authority to deny a permit.
The Sheffield application is unusual because the wind project is already operating and because parent company First Wind, based in Boston, is voluntarily conducting an extensive study on the impact of turbines on bats under a memo of understanding with the agency.
The results of that study, which was begun in April and will run for at least two years under the auspices of highly regarded Bat Conservation International, will enhance understanding of bat behavior and wind turbine projects in Vermont, Markowitz said.
Josh Bagnato, Sheffield Wind’s environmental manager, said the $150,000 study was designed in close cooperation with ANR biologist Scott Darling, who is an expert on bats and white-nose syndrome.
“I would call it groundbreaking,” he said. “It’s pretty innovative.”
White-nose syndrome is a fungus that has infected bat hibernacula (caves) in Vermont and killed an estimated 5 million to 7 million bats in the Northeast. The little brown bat was the most populous and most affected of six species known in Vermont to be placed on the endangered species list. In all, five of the state’s cave-dwelling bats are now listed as either endangered or threatened.
According to Darling, there is some mystery why bats, which use sophisticated echo-location to find insect prey, are susceptible to turbine blades.
“That’s always been the fascinating part,” he says, “why something that can see the thickness of a monofilament fishing line would run into a rotor,” he said.
The study by First Wind involves daily survey of the base of the turbines, with correlations to daily temperatures, wind speed and turbine speed, and even placing out carcasses of any bats to see if scavengers may be removing dead bats and causing undercounting. Bagnato said five people are involved and so far, “to be honest, they’re not finding much,” he said.
According to Bagnato, three dead bats have been found, but none of the three were endangered.
Darling explained that previous wind projects in Vermont were not large enough to impact bats.
“This is the first operating wind facility that has turbines that are tall enough to kill bats,” he said. Sheffield’s wind towers are approximately 420 feet high, according to First Wind. The only other wind project operating, in Searsburg in southern Vermont, has 11 turbines that are only 120 feet high. A dozen projects in Vermont are in the planning stages. http://vtdigger.wpengine.com/2012/05/24/fourteen-industrial-wind-farms-planned-in-vermont-despite-intense-local-opposition/)
To alleviate risk to bats, First Wind is proposing in its permit to voluntarily agree to curb nighttime turbine use in low wind periods under around 9 miles per hour, which is when bats are most at risk, according to Darling.
“Turbine curtailment would begin on April 1 and end on October 31 annually. Little Brown Bats hibernate during the winters, but emerge from hibernation in April – May and then enter hibernation again in September – October,” the permit states.
First Wind argues, however, that if the curtailment wind speed is set too high, it will impact the economics of the project by as much as 25 percent.
“A 25% loss in revenue for the life of the project presents an economic hardship to the project that would make it uneconomical to operate over the long-term,” the application states. It also argued that the certificate of public good to generate power received from the Vermont Public Service Board requires the wind project to meet “the demand for present and future service” and if it does not meet that requirement it faces being decommissioned.
The $100 million Sheffield project provides renewable power to Washington Electric Cooperative in East Montpelier, the Burlington Electric Department, and the Vermont Electric Cooperative in Johnson.
Darling said that there is some evidence, which further research at First Wind will help expand, that curtailing turbine use in low wind when bats are flying can cut mortality by 50 percent to 90 percent.
“That’s a huge benefit,” he said.
Markowitz said while the taking permit on bats is a first, she receives several taking permit applications a month, often for small limited areas where endangered plants might be affected, say in a power line power corridor or development.
She said she will seek an advisory recommendation on the bat permit from the Endangered Species Committee, a citizen panel with scientific expertise attached to her agency, and also receive a recommendation from her staff before issuing a decision.
Markowitz noted future wind project takings cases will be done under a new process authorized in the so-called “fee bill” passed by the Legislature this year. That new process allows the agency to set not only mitigating stipulations on a project’s operation but to impose fees that will allow the agency to do further study on turbine blade impacts on bats and avian species.
An example would be if a project was built close to a bat hibernating cave, then a more extensive study might be required, she said.
Markowitz said the takings permit would be for a two to three year period, which would allow further review and possible adjustments down the road as more data is collected both in state and nationally at other sites.