Siemens begins field testing 6 MW wind turbine for offshore industry

October 8th, 2012 by Siemens AG

The Siemens rotor consists of three 75 metre rotor blades with a diameter of 154 metres (click image to expand - image courtesy of Siemens AG)

On 6 October 2012, Siemens Energy began field testing of its new 154 metre rotor for the 6-megawatt (MW) offshore wind turbine in Østerild, Denmark.

The SWT-6.0-154 turbine is equipped with 75 metres long rotor blades.

With a record rotor diameter of 154 meters, each SWT-6.0-154 turbine can produce 25 GW.h of clean electricity in offshore locations, enough to supply 6,000 households.

As early as May 2011, Siemens installed the first prototype of its new 6-MW turbine using a 120 metre rotor.

It has now been operating successfully for well over a year.

The serial version of the 6-MW turbine will use the 154 metre rotor and is expected to become the new benchmark in the offshore wind industry.

The 75 metre long rotor blade is produced from a single casting without adhesive joints. It is 20% lighter than blades manufactured using traditional methods (click image to expand - image courtesy of Siemens AG)

“The start of field testing of the 154 metre rotor for the 6-MW is an exciting step in the development of competitive technologies for the large offshore wind farms of the future,” said Henrik Stiesdal, CTO of the Wind Power Division within the Siemens Energy Sector.

“We incorporated our technological expertise gained over more than three decades into the development of both the gearless turbine and its 75-metre rotor blade,” he said.

The gearless drive technology permits a compact design.

Using Siemens’ Direct Drive technology the SWT-6.0 is the lightest turbine in its class, having a nacelle weight of only 200 tons.

One of the 75 metre long rotor blades ready to be assembled on the hub (click image to expand - image courtesy of Siemens AG)

This combination of robust design and low weight reduces offshore infrastructure, installation and maintenance costs.

“At the same time, the turbine delivers an increased energy yield and offers greater profitability over its life cycle,” Henrik Stiesdal said.

Siemens developed the SWT-6.0 specifically for demanding conditions in offshore locations.

“The new 6-megawatt turbine is a milestone in wind energy technology,” Stiesdal said.

“Compared to our first 30-kilowatt turbine, which we developed 30 years ago, the new STW-6.0-154 will produce over a thousand times more energy per year.”

The rotor blade development is equally impressive. The first blade of the 30-kilowatt turbine was five metres long, approximately the length of a minibus, while the new 75-metre rotor blades have a length corresponding to that of an Airbus 380 plane, the world’s largest aircraft.

The first Siemens 6-MW turbine was installed in May 2011 at the Høvsore test site in Denmark.

Lifting the 154 metre diameter blades to the nacelle, which weighs 200 tonnes. The tower height is 116 metres (click image to expand - image courtesy of Siemens AG)

Due to height restrictions a 120 metre rotor was used on the prototype. It has now operated for well over a year, setting new production records during the testing.

The record-breaking 154 metre rotor is mounted on a 6-MW turbine installed at the new national test center at Østerild, Denmark, and formal release of the turbine took place at the inauguration of the test center on 6 October, 2012.

The B75 blade used in the new rotor is characterized 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.

An IntegralBlade® is up to 20% lighter than blades manufactured with traditional methods.

Overall, combining an intelligent rotor blade profile with low weight helps lower the cost of wind energy.

The new SWT-6.0-154 is already a commercial success.

The Siemens 6 MW turbine is expected to be used in offshore wind projects around the UK (click image to expand - image courtesy of Siemens AG)

In July 2012, Siemens entered into a Master Agreement with the Danish energy group, DONG Energy, for the delivery of 300 offshore turbines of this type. The wind turbines are expected to be used in projects off the coast of the U.K.

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 6 MW wind turbine will be tested offshore. Both machines for this project will be equipped with the 120 metre rotor.

Wind energy is part of Siemens’ Environmental Portfolio.

In fiscal 2011, revenue from the Portfolio totaled about €30 billion, making Siemens one of the world’s largest suppliers of ecofriendly technologies.

In the same period, Siemens products and solutions enabled customers to reduce their carbon dioxide (CO2) emissions by nearly 320 million tons, an amount equal to the total annual CO2 emissions of Berlin, Delhi, Hong Kong, Istanbul, London, New York, Singapore and Tokyo.


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