You are here

World’s longest blades for 6MW wind turbine tested in Denmark

German firm Siemens’ record-breaking 154m rotor blades to become “benchmark for offshore wind industry

The 154m rotor is lifted by cranes to the top of the Siemens' 6MW wind turbine tower

Tests on the world’s longest wind turbines blades have started in Denmark. German firm Siemens Energy has begun field testing its record-breaking 154m rotor for the 6MW offshore wind turbine at the national test centre at Østerild. The rotor is set to become a “benchmark” for the offshore wind industry.

With blades at 75 meters in length, the SWT-6.0-154 turbine can produce 25 million kWh of clean electricity in offshore locations. This is enough to power 6,000 households.

Siemens said the B75 blade used in the rotor is characterised by high stability and low weight. Special aerodynamic profiles deliver optimum performance at a wide range of wind speeds. For the manufacturing of the B75 blade, Siemens uses the patented IntegralBlade process, which permits rotor blades to be produced from a single casting without adhesive joints.

The company said the IntegralBlade is up to 20 per cent lighter than blades manufactured with traditional methods. Combining an intelligent rotor blade profile with low weight helps lower the cost of wind energy.

Henrik Stiesdal, CTO of the wind power division of Siemens Energy, said: “The start of field testing of the 154m rotor for the 6MW is an exciting step in the development of competitive technologies for the large offshore wind farms of the future. We incorporated our technological expertise gained over more than three decades into the development of both the gearless turbine and its 75m rotor blade.”

Siemens installed the first prototype of its new 6MW turbine using a 120m rotor in May 2011. It has now been operating successfully for well over a year. The serial version of the 6MW turbine will use the 154m rotor, which the company said is expected to become the “new benchmark in the offshore wind industry.”

Siemens will soon install two more SWT-6.0 prototypes in the British offshore wind power plant, Gunfleet Sands. This will be the first time that the Siemens 6MW wind turbine will be tested offshore. Both machines for this project will be equipped with the 120m rotor.

“The new 6MW turbine is a milestone in wind energy technology,” said Stiesdal. “Compared to our first 30kW turbine, which we developed 30 years ago, the new STW-6.0-154 will produce over a thousand times more energy per year.”