London, UK A trend towards larger capacity turbines with longer blades and larger rotor diameters has been long established, with OEMs continuing to offer existing machines with a range of rotor diameters. But now, a new generation of still larger machines has been unveiled.

Among those companies unveiling new models REpower Systems AG, introduced its 3.2M114. Optimised for low-wind locations, the 3.2 MW turbine has a 143 metre hub height and a 114 metre rotor.

A hybrid tower made of concrete and steel is to be used. At the end of 2010, two 3 MW turbines were erected on 128 metre hybrid towers in Germany. A second 3.2M114 prototype, with a hub height of 93 metres and a steel tube tower is due to be erected late 2011.

Matthias Schubert, REpower Chief Technology Officer (CTO) says: "Especially in the European market, greater hub heights allow new sites to be developed. In southern Germany, for example, significant unexploited potential still exists in hilly terrain and forested areas."

REpower majority-owners Suzlon, meanwhile, has also launched a low-wind version of an existing platform recently with its new S9X suite of machines.

Similarly, Alstom has revealed an upgrade to its existing 3 MW ECO 100 platform to specifically address low wind speed sites with a new (IEC Class III-A) turbine, the ECO 11X, with a larger rotor diameter. The exact rotor diameter, in the range of 115-125 metres, will be released in the second half of 2011, when the turbine will be offered for deliveries starting in 2013.

New Entrants, New Technologies

A new entrant to the offshore sector, Doosan Power Systems, part of the Korean industrial conglomerate Doosan Heavy, has unveiled plans to develop a 6 MW offshore specific turbine. It plans to develop the turbine in order to enter the European market, where the company says it has identified a significant opportunity by 2020.

Doosan says it has decided to aggressively step up its campaign to industrialise its wind power business. The company also says it plans to co-develop core parts, including blades, with local small and medium-sized enterprises.

Offshore Entries

Germany's Nordex SE has revealed its new platform, the N150/6000, which has been developed specially for offshore. With a 150 metre rotor diameter, it has a nominal output of 6 MW and is a direct drive machine with a permanent magnet generator and a full power converter, a move the company says has enabled it to keep the, undisclosed, top head mass low. Nordex says it is currently engineering this drive train design in conjunction with its suppliers.

Vestas has also marked a new move back into offshore with a 7 MW machine boasting a massive 164 metre rotor diameter.

This new geared machine, at 7 MW, is significantly larger than previously announced plans for a 6 MW machine. The V164-7.0 MW features a swept area of more than 21,000 m².

renewableenergyworld.com