Watching the Skies over Wind FarmsBy Derrill Holly | ECT Staff Writer Published: August 22nd, 2012
More wind turbines are turning at wind farms in the Upper Midwest, but if certain creatures fly near some facilities, two words uttered by contract biologists could bring turbines in their path to a full stop: whooping cranes.
The huge white birds are the largest native to North America. Near extinction a century ago, and on the endangered species list since its creation in 1967, they are making a comeback. More than 400 of them now live in the wild.
“If we see a whooping crane, we’ll start shutting down the towers as fast as we can,” said Daryl Hill, Basin Electric Power Cooperative’s supervisor of media relations and communications. “But we’ve never had a sighting at our Minot project.”
The Bismarck, N.D.-based G&T agreed to a three-year whooping crane monitoring program for each of the wind farms it has developed and operates. Since the birds are migratory, monitoring near the 82 turbines at Basin Electric’s Minot Wind Project in North Dakota and the 108 turbines at the G&T’s Crow Lake project in South Dakota occurs in spring and fall.
At least one biologist has scanned the skies daily at the 30,000-acre Minot location and two have been on site in South Dakota, said Hill.
They watch for the distinctive white bodies and black-tipped wings that sometime appear in small groups, in the company of sandhill cranes. Migrating cranes typically cover 25 to 50 miles a day. North Dakota sightings trigger shutdowns of turbines within a mile radius of the bird’s path. A sighting in South Dakota will trigger a two-mile shutdown.
“Basin Electric employees at the wind farms are trained to spot whooping cranes,” said Hill. “They can alert our dispatch center to shut down the turbines if one is seen.”
A population of 100 whooping cranes reintroduced in Wisconsin has learned to migrate to Florida. A larger, natural flock of 300 birds uses the central flyway between the Aransas marshes on the Texas Gulf Coast and Wood Buffalo National Park in Alberta, Canada. The route carries them through parts of six states, including the Dakotas.
The G&T alerts wind farm staffers to be on the lookout for the birds from April 1-May 10 and Sept. 10-Oct. 31, when the birds are most likely to fly through the Dakotas.
Refresher training with site-specific videos is provided before each migration period, Hill said. “We shut down turbines at our Crow Lake Wind Project north of White Lake, S.D., last spring, after a pair of whooping cranes was detected.”
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