coastal ecology for thirty years. “I thought it would be exceptionally unlikely that we could identify a place in state waters with low enough risk to pursue wind power,” he says. Peterson leaned on his network of friendships and working relationships to gather information about the ecology of eastern North Carolina. He also relied on research assistant Joan Meiners and two undergraduates, who traveled throughout coastal areas to talk to experts on birds, bats, turtles, fish, butterflies, and sea mammals. They also spoke to duck hunters, ecotourism professionals, whale watchers, park service workers, academics, and fishermen. Meiners conducted seventy interviews and came away with stacks of information. Two other undergrads were charged with finding every environmental-impact study for wind-farm development, whether on land, over water, or from other countries. Then Peterson and research associate professor Steve Fegley sorted through all of it. As Peterson suspected, great portions of coastal estuaries and sounds are home to too many species with fragile habitats that would be disrupted or even destroyed if wind turbines were installed. But he also found that the farther you get from land and the farther east you get from the barrier islands, the less risk there is to animals— until you approach the Gulf Stream, a river of animal diversity. “One of the things I found most interesting is the behavior of songbirds,” Peterson says. “These migratory birds typically fly higher than windmills, but they drop to lower levels during stormy weather, putting them well within range of windmills. And these birds are in great decline—bluebirds, warblers, sparrows, the birds in our backyards that we love.” Peterson also found that insects are attracted to white windmill blades. And these insects attract bats, which have been known to chase insects toward turbines. The blades don’t always turn very fast but they do create drastic air-pressure differences in the vortices behind the turbines. And these varying pressures have caused bats to explode. Peterson points out that some bat species eat the insects that attack our crops. “Like the bees that pollinate our crops, the bat is one of these organisms that we kind of take for granted. But we shouldn’t.”
Peterson does point to solutions: painting the turbine blades black, for instance. Also, if bats become a problem during a pilot study, researchers could attach devices to the turbines that emit ultrasonic sounds that humans wouldn’t hear but would keep bats away. According to the impact studies from Denmark, most birds maneuver with ease between turbines or completely around wind farms. Still, Peterson says that some parts of North Carolina’s sounds are blanketed with birds during migration season. These areas—from the shoreline to two miles out—are the same places that proved to be off-limits because of fisheries. Peterson also studied the benefits that wind turbines could bring to marine life, such as the creation of artificial oyster reefs where turbine bases would sit on the ocean floor. There are two ways to anchor a 465-foottall wind turbine in water, according to the Danish firm Ramboll Wind, which was on Elfland’s project team and designed about 65 percent of the water-based turbine foundations in use around the world. One way is to place the turbine on a two-hundred-meter-wide concrete slab that sits on the ocean floor. This gravity-based system would be covered with thousands of tons of rocks that could serve as reefs for marine life. To use the gravity-based system, though, the ocean floor has to be relatively flat and very stable. North Carolina’s sounds are known to be kind of shifty. One day there’s a channel to the shoreline; the next day it’s a sandbar.
The second way to anchor a turbine foundation is to pile drive something called a monopile into the sea floor. The turbine sits on this cylindrical monopile. This system is less expensive and will be used in the Pamlico Sound pilot study. When Elfland needed someone to figure out where wind turbines could be anchored, Peterson and Seim recommended Stanley Riggs, a geologist at East Carolina University who has spent much of his career mapping the ocean floor off the North Carolina coast and researching the geology of the Pamlico Sound. Like the other researchers, Riggs found many coastal regions ill-suited for wind-turbine installation. But large areas near the Virginia border, south of Cape Lookout, and surrounding Cape Hatteras are well-suited for wind development. One of these areas is northwest of Hatteras Island in the Pamlico Sound. Seim says that ecological risks and oceanbottom geology are two of the three main things that limit coastal wind-farm development. The third is military use. “Coastal areas are very popular with the military,” he says. “They’ve lost a lot of operating space since the 1950s, and they don’t want to lose any more because it’s becoming increasingly hard to find training areas. Eastern North Carolina is one of their favorites.” Elfland met with the U.S. Marine Corps and her team also made sure that the U.S. Navy’s training grounds were excluded from lists of possible wind-farm locations. When all was said and done, the researchers concluded that there was one place in MARGARITE NATHE
Pete Peterson: “I thought it would be exceptionally unlikely that we could identify a place in state waters with low enough risk to pursue wind power.” endeavors 33