Four leases for 742,000 acres of sea south of Martha's Vineyard - a area roughly the size of Rhode Island - will be put up for bid at a wind power auction on Jan. 29, 2015.
If leased and developed by the power industry, the area has the potential to provide wind-generated electricity to 1.4 million homes, according to the Bureau of Ocean Energy Management, which announced the auction date Monday and pitched it as part of President Barack Obama's climate action plan and efforts to reduce carbon pollution.
The area stretches 33 nautical miles from north to south and 47 nautical miles from east to west and is the largest offshore wind tract in federal waters in the United States.
Twelve companies are qualified to bid for the project, which is farther out to sea than other wind projects, such as Cape Wind, in development off the shores of Massachusetts and Rhode Island.
Deepwater Wind New England, which has plans to build 200 offshore turbines to the north and west of the tract, is qualified to try for the larger plot. EDF Renewable Development, Energy Management, Fishermen's Energy, Green Sail Energy, IBERDROLA RENEWABLES, NRG Bluewater Wind Massachusetts, OffshoreMW, RES America Developments, Sea Breeze Energy, US Mainstream Renewable Power (Offshore) and U.S. Wind are all qualified to bid.
Known as the Massachusetts Wind Energy Area, the plot 12 nautical miles off the coast could support between 4 and 5 gigawatts of generation, according to BOEM.
If the area was built out to the maximum extent, generating a total of 4 gigawatts with 5 megawatt turbines, the acreage could contain about 800 turbines, according to BOEM spokeswoman Tracey Moriarty.
The area far surpasses the Cape Wind tract in size. Long in planning and tied up in litigation, Cape Wind is still in the process of attracting investors for its plan to be the first offshore wind farm in the United States, building 130 turbines in Nantucket Sound.
The New England Fishery Management Council, responding to an earlier version of the area in 2012, said it is used by trawlers and gillnets seeking out cod, flounder and monkfish, as well as hydraulic clam dredging, squid and herring trawling, and lobster trapping.
The Massachusetts Audubon Society also raised concerns about impacts on birds. BOEM said it adjusted the area to exclude "an area of high sea duck concentration, as well as an area of high value fisheries."
The size of the Wind Energy Area is more than four times the size of Buzzards Bay.
To date, BOEM has awarded seven commercial wind energy leases for the waters off the Atlantic coast, including non-competitive leases for Cape Wind in Nantucket Sound and an area off the Delaware coast. Competitive lease sales have generated more than $14 million in high bids for more than 357,500 acres in federal waters, according to BOEM.
Earlier this month, Gov. Deval Patrick said he expected the federal auction would occur in December.