BatShield sounds like something out of a comic book or superhero movie, but this piece of software developed by Gamesa and tested in Lewes over the last two summers is designed to literally save the lives of bats.
University of Delaware and Delaware State University researchers, working with the company, have been attempting to minimize the impact of wind turbines on bats and birds. The project was coordinated by UD professor Jeremy Firestone of the College of Earth, Ocean and Environment, using the college’s turbine at its Lewes campus.
The research team monitored bird and bat activity around turbines starting a few months after it was installed near the Delaware Bay in 2010. The bay is an important stopover location for avian flocks during migration.
At first, researchers were most concerned about the impact of the turbine on birds, but were surprised to discover there were few bird strikes, Firestone said. Meanwhile, within a year’s time, there were an estimated 100 bat deaths from the turbine.
The bats included four or five species, and none of them are endangered, Firestone said. Bats are migratory, and are around the turbine for about three months of the year in late summer, he said. They are most mobile in the few hours after dusk, and tend to move around more “when it’s not that breezy out,” Firestone said.
UD turned to Kevina Vulinec, DSU associate professor of natural resources, as principal investigator of the portion of the research dealing with bats.
Although it might appear a wind turbine is always able to spin, Firestone said this is not the case. When it’s just a little breezy, the turbines are locked in place to avoid wear and tear when it’s not generating much electricity, Firestone said. Researchers created an experiment during the months when bats were nearby: One week it would be business as usual, with the turbine turning on when the wind is blowing 3 meters per second or more, he said.
The next week, researchers would increase the “cut-in” speed to higher wind speeds of 5 meters per second or more during the first hours after dusk, Firestone said. The cut-in speeds would vary back and forth every other week during the season when bats were around, he said.
With the turbine turning on only at higher speeds, there was a 90 percent drop in bat fatalities, he said.
“You’re not losing much power, and you’re not losing much revenue,” Firestone said. In exchange, he said, “you can make a lot of good will.”
Vulinec said the 90 percent reduction was for just one season, and additional years will bring more information. She said they are playing with other wind speeds to test the impact on bat deaths. “Hopefully this is something that will help both the bats and the energy companies,” she said.
It’s unclear why bats are attracted to wind turbines, and researchers are working on various hypotheses, like whether they are attracted to insects around the turbine, she said.
Bats, she said, are important ecologically, as the only significant predator that hunts night-flying insects like mosquitoes, as well as crop pests.
The research was enacted with a prototype version of the software – “BatShield” – created by Gamesa, the developer that built the wind turbine. The University’s Blue Hen Wind and Gamesa have a joint venture, First State Marine Wind LLC, that owns the turbine, which sends its power to the university’s campus there, as well as the residents of the City of Lewes.
Gamesa is marketing the product as a “nice software add-on that gives the operator a lot of control,” and allows them to make the adjustments easily, Firestone said.
“Having a partner who can support objective measurement of a product’s effectiveness is always important,” said Francis Fuselier, a spokesman for Gamesa. He described the work with the university as “an excellent collaborative relationship,” and said UD’s work “will help us make adjustments and improvements to our product.”
The earliest prototype of the product was installed in 2012, and was released commercially in 2013. With the positive results seen at UD, “we’d expect other wind farms will consider the benefits of BatShield for their projects,” Fuselier said.
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