Offshore Turbine

French company Alstom has won a contract from Deepwater Wind to supply five offshore wind turbines for the 30MW Block Island pilot wind farm located off the coast of Rhode Island, the US.

Under the contract, Alstom will manufacture the Haliade 150-6MW direct drive wind turbines and provide 15 years of operation and maintenance support for the project.

Owned and operated by Deepwater Wind, the project is claimed to be one of the first offshore wind farms in the US and will be the first to feature Alstom’s Haliade 150-6MW turbines.

Alstom claims the Haliade turbine operates without any gearbox with the help of a permanent-magnet generator and features the Pure Torque design that diverts unwanted mechanical stress towards the tower, optimising performance and reliability.

In addition to this, the turbine’s 150m diameter rotor is claimed to be providing an energy yield that is 15% better than existing offshore turbines.

Having originally developed such turbines in its Marine Energies Research and Development Centre in Nantes, Alstom will manufacture the contractual equipment at its French factories.

Alstom will produce nacelles and generators in Saint-Nazaire due to be completed at the end of 2014, and blades and towers in Cherbourg, for which a building permit has been submitted.

Alstom renewable power sector president Jerome Pecresse said the latest contract represents the company’s commercial dynamic in offshore wind and the credibility of its technology platform.

"The turbine’s 150m diameter rotor is claimed to be providing an energy yield that is 15% better than existing offshore turbines."

Pecresse said, "It shows that we can be successful in serving both the growing international markets and our strong domestic market here in France.

"It also allows us to concretely implement the various partnerships we have formed with local companies."

The project will generate more than 125,000MWh annually, enough to power approximately 17,000 homes, and will export the output to the mainland electric grid through the 21-mile, bi-directional Block Island Transmission System.

Block Island will lead to the development of a 1GW offshore wind farm supported by a regional transmission system linking Long Island, New York and south-eastern New England.

Image: Haliade 150-6MW offshore wind turbine in Belwind, Belgium. Photo: courtesy of Alstom/Broadcast Assistance Belgium/Johann Roggeman.