The builder of the first offshore wind energy farm in the U.S. will supply electricity to about 50,000 homes in Delaware for 25 years starting 2012.

The power supply, which represents 16 percent of the electricity the proposed Delaware Offshore Wind Park (DOWP) will generate, is provided under a contract between Bluewater Wind and utility company Delmarva revealed on Monday.

Bluewater spokesman Jim Lanard said the rest of the projected generating capacity of the wind farm will be sold to other customers, including the Delaware Municipal Electric Corp.

The $1.6-billion DOWP will have 150 wind turbines anchored 75 feet below the seafloor about 12 miles off Rehoboth Beach. The wind turbines, with blades up to 150 feet long, will sit on poles extending 250 feet above the Atlantic Ocean.