Environmental Effects of Offshore Wind Energy Development

iii The development of offshore wind energy in the United States will be accelerated if floating wind platforms are successfully developed to harvest the largest and most consistent bands of wind over the oceans. DeepCwind, a consortium headed by the University of Maine will test the first U.S. offshore wind platforms in 2012. In advance of final siting and permitting of the test turbines off Monhegan Island, residents of the island off Maine require reassurance that the noise levels from the test turbines will not disturb them. Pacific Northwest National Laboratory, at the request of the University of Maine, and with the support of the U.S. Department of Energy Wind Program, modeled the acoustic output of the planned test turbines. A commercial software package was used to model sound propagation over water due to three Northwind 100 wind turbines located three miles from the east coast of Monhegan Island, Maine. Sound pressure levels were calculated at a location approximating the island’s central eastern shore region at a height of 1.5 m. Three types of modeling calculations were performed using worst-case conditions for sound to reach the island. In all cases the calculated noise reaching Monhegan Island is below nationall