6 MW wind turbine promises to be light

Siemens Energy has installed the first prototype of its next generation offshore wind turbine in Høvsøre, Denmark, and has today initiated the first trial operation. The new SWT-6.0-120 wind turbine with a power rating of 6 megawatts (MW) and a rotor diameter of 120 metres uses direct drive  technology. Nacelle and rotor of the SWT-6.0-120 weigh together less than 350 tons. 

The new SWT-6.0-120 is the third direct drive wind turbine type developed by Siemens. The company is in the process of testing and validating the performance before the product will be officially launched for sale in the near future. “In tendency large wind turbines have always been heavier per megawatt than small ones. The SWT-6.0-120 breaks this rule, having a weight per megawatt similar to that of many turbines in the 2 to 3 MW range”, says Henrik Stiesdal, Chief Technology Officer of the Siemens Wind Power Business Unit. ”Reaching this low weight with a strong and robust machine is the result of targeted innovation combined with our more than thirty years of wind industry experience”, Stiesdal adds. The low weight of the SWT-6.0-120 wind turbine will contribute to a significant reduction in the cost of energy for offshore wind power plants. The low weight positively impacts the costs of the turbine itself, but also that of the tower and the support structures.

“We have developed the SWT-6.0-120 wind turbine specifically for the offshore projects of the future. Our direct drive technology offers a smart, straightforward design that minimizes the number of moving parts in the wind turbine. We expect that our new SWT-6.0-120 will set new standards for performance, robustness and optimized maintenance concepts, which are major advantages in the harsh conditions offshore,” says Henrik Stiesdal.

The new Siemens SWT-6.0-120 makes use of several key technologies that are well-proven in offshore applications of the market-leading Siemens 3.6 MW turbine. The first series of the 6 MW wind turbine will feature the same proven B58 blade as is now used on the SWT-3.6-120. Other proven technologies employed in the new SWT-6.0-120 wind turbine include the Siemens IntegralBlade® design for blades manufactured without glue joints.

The SWT-6.0-120 is designed and optimized for service and maintenance work. It features the Siemens advanced diagnostics systems to reduce customer risk and enable maximum reliability and availability. A particular offshore feature is a helicopter-hoisting platform which is integrated in the nacelle rear and allows easy and safe access for service technicians.

The first 6MW prototype will now undergo an extensive commissioning and trial operation process before being released for automatic operation. During 2011, Siemens will install additional prototypes of the SWT-6.0-120 wind turbines for further testing and validation. A number of pre-series 6 MW wind turbines will be installed during 2012 and 2013 for further tests and optimization of the turbine performance. Serial production is planned for 2014.