Siemens Energy has installed the prototype of a new 4 MW wind turbine in Østerild, Denmark. The WTG is designated SWT-4.0 and is based on the established technology of the SWT-3.6, the world’s most installed offshore turbine. So far, Siemens has installed nearly 500 of its 3.6 MW units and has another 1200 in its order backlog.

The prototype is currently fitted with the standard 120 m rotor of the 3.6 MW unit but will shortly be upgraded with a 130 m rotor with 63 m rotor blades. Following its testing programme the SWT-4.0-130 is scheduled to be put on sale in the spring of 2013. Serial production is planned for 2015.

Thanks to a generator and rotor upgrade, the new 4MW allows our customers a faster return on investment than our 3.6 MW wind turbine", says Henrik Stiesdal, chief technology officer of the company’s Wind Power division. The new WTG employs several key technologies that have been proved in offshore applications of the 3.6 MW unit. The nacelle and tower structures are essentially upgraded 3.6 MW variants, and the blades are manufactured using the Siemens IntegralBlade technology without glue joints. New technologies incorporated in the SWT-4.0-130 include a new aeroelastically tailored 63 m (B63) blade featuring improved performance and reduced loads.