Last year saw construction begin on the US's first offshore wind farm. The 30-MW Block Island Wind Farm will be located about 3 mi (4.8) off the coast of Block Island in the US state of Rhode Island, but its components are currently being constructed around the world.
General Electric (GE) is constructing the turbines on behalf of US offshore wind developer Deepwater Wind. The first sections of the towers upon which the turbines will be supported are being assembled in nearby Providence. The first direct-drive permanent magnet generators, however, is being assembled in Saint-Nazaire, France. Similarly, a variety of other components, including the blades and nacelles, will be shipped from Europe for assembly on site.
The wind farm's 30-MW capacity will be met using five of GE's 6-MW "Haliade" turbines, which the company says are some of the largest in the world. They have a diameter of 150 m (490 ft), which the firm likens to being twice the size of a Boeing 747's wingspan, and a height of 170 m (560 ft).
Once in operation, the Block Island Wind Farm is expected to produce around 125,000 MWh of electricity annually, enough to power 5,000 households and to meet around 90 percent of Block Island's electricity demand.
The Block Island Wind Farm is expected to be completed by the end of this year. The turbines are each expected to have a lifespan of 25 years, during which they will save an estimated 21,000 tons (19,050 tonnes) of CO2 compared to electricity generation via non-renewable sources.