Cape Wind Associates plans to begin construction this fall on its controversial 454-MW wind farm in Nantucket Sound after receiving final approval for its construction and operating plan on April 19 from the Bureau of Ocean Energy Management, Regulation and Enforcement. The farm, which should take about two years to build, has been in the works for more than 10 years and was fought by environmentalists and residents of Cape Cod. Cape Wind is still evaluating bids for construction of the farm, estimated to cost $2.5 billion. The project, about five miles off the Massachusetts coast, will consist of 130 3.6-MW turbines, each with a maximum blade height of 440 ft.