Siemens Energy has begun field testing its new 154-meter rotor on a 6 MW offshore wind turbine in Østerild, Denmark. This SWT-6.0-154 turbine has the longest rotor blades in the world, each measuring 75 meters in length. With a record diameter of 154 meters, each SWT-6.0-154 turbine can generate 25 million kWh of green electricity offshore, enough to power 6,000 homes.
Back in May 2011, Siemens installed the first prototype of its new 6 MW turbine with a 120-meter rotor (SWT-6.0-120). It has now been running perfectly for over a year. The production version of the 6 MW turbine will be equipped with the 154-meter rotor and should set new standards in offshore wind power.
" The launch of real-life testing of the 6 MW turbine with 154-meter rotor is an exciting milestone in the development of competitive technologies for the large-scale offshore wind farms of the future. We have drawn on over 30 years' experience in this technical field to develop this drive-free turbine with its 75-meter-long rotor blades. "explains Henrik Stiesdal, Chief Technology Officer (CTO) of the Wind Power Division within Siemens' Energy Sector.
This drive-free technology makes for a compact design: thanks to Siemens Direct Drive technology, the SWT-6.0 is the lightest turbine in its class, with a nacelle weighing just 200 tonnes. This robust design, combined with low weight, reduces the costs associated with infrastructure, installation and maintenance of offshore wind turbines.
" This turbine also offers greater energy efficiency and better profitability over its life cycle. "adds Henrik Stiesdal. Siemens has specially developed the SWT-6.0 for operation in the harsh conditions of the high seas. " New 6 MW turbine marks a milestone in the evolution of wind turbine technologynotes Henrik Stiesdal. Compared with the first 30 kW turbine we developed 30 years ago, the new STW-6.0-154 will generate 1,000 times more electricity per year. "The evolution of the rotor blade is equally impressive: the first blades of the 30 kW turbine were five metres long, roughly the length of a minibus, while the new 75-metre rotor blades have a wingspan equivalent to that of an Airbus 380, the world's largest aircraft.
The first Siemens 6 MW wind turbine was installed in May 2011 at the Høvsøre test center in Denmark. Due to height restrictions, a 120-meter rotor was used on this prototype. It has now been in operation for over a year, and has set new production records during this test phase. The record-breaking 154-meter-long rotor is installed on a 6 MW turbine at the new national test center in Østerild, Denmark, and was officially commissioned at the center's inauguration on October 6, 2012.
The B75 blade used on the new rotor features high stability and low weight. Its special aerodynamic profile offers optimum performance over a wide range of wind speeds. For the construction of the B75 blade, Siemens used the patented IntegralBlade® process, which enables rotor blades to be manufactured as a single unit, with no junction points. An IntegralBlade® blade weighs up to 20 % less than a blade built using conventional methods. Ultimately, the well-thought-out profile of these blades increases energy efficiency, while their light weight has a positive impact on the cost of the mast and foundations.
Siemens will soon be installing two more SWT-6.0 prototypes at the Gunfleet Sands wind farm in the UK. These will be the first prototypes of this new generation of offshore wind turbines to be tested on the high seas. Both turbines will be equipped with the 120-meter rotor.