REpower commissions its tallest wind turbine

At the beginning of July, REpower Systems SE successfully commissioned its tallest wind turbine Winnberg 4 in Sengenthal near Neumarkt, Bavaria. The turbine, with a rated power of 3.2 megawatts, a rotor diameter of 114 metres and a 143 metre concrete and steel hybrid tower, has a total height of 200 metres and is thus the tallest wind turbine that REpower has erected to date. It was built on behalf of locally based Max Bögl Windpower GmbH. With the optimally matched ratio between rated power, rotor diameter and hub height of 143 metres, the turbine is especially suited for locations with low wind speeds as well as in hilly terrain and forested areas. Compared to a 3.2M114 with a hub height of 93 metres, a hub height of 143 metres can result in an increase in yield of up to 50 percent in low-wind locations.

Matthias Schubert, Chief Technical Officer at REpower Systems SE, explains the background: "With each additional metre in height above a hub height of 100 metres, we can gain an additional energy yield of up to one percent".

With the 3.XM series at hub heights above 100 metres, REpower deploys a hybrid tower made of a combination of pre-manufactured steel-concrete segments and a standardised steel tower, which is already being used successfully with the REpower 3.4M104 with a hub height of 128 metres.

As Schubert says, "The unique hybrid tower technology permits towers to be extended by up to 50 percent and overcomes natural site limitations. At the same time, the segmented construction supports an economic, nearly weather-independent installation and guarantees a short construction time".

With the installation of wind turbines with a hub height of up to 143 metres, new challenges arise with regard to transport and installation. An important component of the technical design is a mobile tower crane, which was first deployed by REpower during the erection of the wind turbine at the Winnberg site. This crane "climbs up" along the tower according to the progress of construction, thus permitting a cost- and space-saving installation of the turbine even in forested areas and in complex terrain. For the hybrid tower design in combination with the self-climbing tower crane for the Winnberg project, REpower and the manufacturer of the concrete segments, the Max Bögl Group, collaborated with crane supplier Liebherr in order to take advantage of its long-term experience in the crane industry. With this concept, the time required for onsite installation is significantly reduced.

Jens Müller-Nielsen, Managing Director of REpower Systems GmbH, the subsidiary responsible for business in the German market, adds: “In Germany, additional projects with REpower 3.2M114 wind turbines with a 143 metre hub height are in planning for 2012 or are currently being implemented. For instance, six turbines of the same type are currently being built at the wind farm Berching, Bavaria’s largest civic wind farm, financed by over 1.000 private individuals”.

Further information on in the wind farm Berching can be found on www.windpark-berching.de.