The Cape Wind Project is a $900 million proposed offshore wind farm on Horseshoe Shoal in Nantucket Sound off Cape Cod in the U.S. state of Massachusetts (41°32′31″N 70°19′16″W / 41.542°N 70.321°W / 41.542; -70.321Coordinates: 41°32′31″N 70°19′16″W / 41.542°N 70.321°W / 41.542; -70.321) proposed by a private developer, Cape Wind Associates. If the project moves forward on schedule, it will become one of the first offshore wind energy projects in the United States. The project has been fought by the Alliance to Protect Nantucket Sound, formed in 2001 to oppose the proposal. The footprint for the proposed project covers 24 square miles, and would be 4.8 miles (7.7 km) from Mashpee, on the south coast of Cape Cod, and 15.8 miles (25.4 km) from the island town of Nantucket. The project envisions 130 horizontal-axis wind turbines, each having a hub height of 285 feet. The blade diameter is 364 feet (111 m), with the lowest blade tip height at 75 feet (23 m) and the top blade tip height at 440 feet (130 m).[2] The turbines would be sited between 4–11 miles offshore depending on the shoreline. At peak generation, the turbines will generate 454 megawatts (MW)[1] of renewable electricity. This is enough to meet the needs of 420,000 homes. The project is expected to produce an average of 170 megawatts of electricity, about 75% of the average electricity demand for Cape Cod, Martha's Vineyard, and Nantucket island combined.[3] It could offset close to a million tons of carbon dioxide every year and should produce enough electricity to offset the consumption of 113 million gallons of oil annually.[4] Currently 45% of the Cape region's electricity comes from the nearby Canal Power Plant in Sandwich, which burns bunker oil and natural gas.[5][6] The Cape Wind proposal is distinct in that it would directly offset petroleum combustion, unlike most of the United States where electrical power generation from oil is rare and coal power is more common. Additionally, this project would decrease the amount of oil shipped to the Cape Cod power plant; fuel for this plant has been part of two major oil spills. The first was on December 15, 1976, when the tanker Argo Merchant ran aground southeast of Nantucket Island, Massachusetts spilling 7.7 million U.S. gallons (29,000 m³) of oil.[7] The second occurred in April 2003, when a Bouchard Company barge carrying oil for the Mirant Canal Generating Plant ran aground spilling 98,000 gallons of oil, which killed 450 birds and shut down 100,000 acres (400 km²) of shell fishing beds.[8]