The Cape Wind proposal off Cape Cod has been in the works for nearly a decade. Here is the plan: 130 wind turbines to be installed; nominal generation capacity — 468 megawatts total; rotating blades of each unit will sweep the area of two football fields; turbines spaced out over 25 square miles of ocean; 1.4 billion kilowatt-hours annual total electricity generated. The Maine Yankee nuclear plant produced nearly four times this amount of electricity when it was having a bad year.