FACTBOX-Facts about wind power in the United States

July 28 - A proposed wind farm in Nantucket Sound is in the running to become the United States' first offshore wind project, and could add clean energy capacity to the densely populated Northeast.

Below are facts about wind power in the United States:

* Cape Wind's 130 planned turbines would generate 420 megawatts of power, enough to meet 75 percent of the demand on Cape Cod and the islands of Nantucket and Martha's Vineyard.

* The United States currently has 28,206 megawatts of installed wind turbines, which represents about 1 percent of the nation's electricity supply. All the utility-scale developments have been built on land, with the most capacity in Texas, Iowa, California, Minnesota and Washington.

* In the United States, wind power now produces enough electricity to prevent the emission of more than 29 million tons of carbon dioxide. It would take 17,000 square miles (44,000 sq km) of forest -- an area larger than Massachusetts and Connecticut -- to absorb that much of the greenhouse gas.

* The U.S. offshore industry has focused on the East Coast rather than the West since the Pacific Ocean gets deeper more quickly, making construction a greater challenge. In Europe, where offshore wind farms have been in operation since the 1970s, most are located in 80 feet (24 metres) of water or less.

* U.S. states are also hoping new investment in offshore wind will bring jobs. Rhode Island in particular -- with one of the highest unemployment rates in the nation -- is counting on a staging area in Quonset Point that Deepwater plans to use for building its projects to employ about 800 people.

Sources: American Wind Energy Association, Cape Wind