Alstom has completed the first coastally located installation of its new-generation offshore wind turbine, the 6MW Haliade 150. It is sited off Ostend harbour at the Belwind site in Belgium. This is the largest (in size) offshore wind turbine ever installed at sea, and equal to the largest in capacity. Thanks to its 150 metre rotor, says Alstom, with blades stretching 73.50 metre, the turbine is more efficient, since its yield is 15% better than existing offshore turbines.
Following successful onshore tests performed on the first Haliade 150 commissioned in March 2012 at Le Carnet site in France, which successfully obtained in May 2013 the International Electrotechnical Commission’s power performance measurement certification, this installation will help in to establish how the machine behaves within the offshore environment for which it was specifically designed and developed.
The 61 metre jacket has been set on pillars which have been sunk to a depth exceeding 60 metres. Then the 3 elements of the 78 metre tower were gradually assembled on the jacket. The nacelle was then set in place at its towering height of over 100 metres above sea level. The total weight of the turbine and its structure comes to 1500 tonnes.
This new-generation wind turbine operates without a gearbox using direct drive. This and the permanent-magnet generator results in fewer mechanical parts inside the device, making it more reliable, says Alstom and thus helping to reduce operating and maintenance costs. The device also features Alstom’s ‘Pure Torque’ design, which protects the generator by diverting mechanical stress towards the tower.
Now that it has installed this wind turbine in sea waters, Alstom has reached an important milestone in the industrialisation process of its 6MW turbine. The Carnet installation should be securing its final certification during the first half of 2014. The construction of the two factories in Saint-Nazaire (nacelles and generator) is well underway, and will end around summer 2014. The construction of the two Cherbourg factories (blades and towers) will follow.
