5M goes offshore

The challenge of offshore wind – proven technology in new dimensions
The idea of installing offshore wind farms has been promoted in Europe since the early 1980s. Our neighbours such as Denmark or the Netherlands were pioneers in the field but the development of offshore technology has also advanced well in Germany. Offshore wind farms with a rated power of up to 1,000 MW will have the same capacity as conventional power stations. Based on the technical concept, the development expertise and the ongoing operation of the MD (1.5 MW) and MM (2 MW) wind turbines, REpower Systems AG is laying the foundations for the economical deployment of wind energy by developing the 5M. The largest wind turbine with a rotor blade diameter of 126 metres – the size of two soccer fields when spread out – has been operating as a prototype at the onshore location of Brunsbüttel with an availability of over 95% since 2004. By now more than a dozen 5M are erected on- and offshore.

The reliability of the components plays a dominant role in offshore use compared to onshore use. In particular, the gear system has to be adapted, something that was achieved by using high quality components in conjunction with a new overall design. The use of redundant components is essential due to the limited accessibility of the turbine on the open sea.

The REpower 5M has been optimally designed for offshore operation, has already been tested sufficiently onshore and is now ready to go offshore. Wind farms have been authorised in Germany for installation in the North and Baltic Sea in recent years; it has been unclear for a long time who bears the costs e.g. for the connection of offshore wind energy turbines to the power grid. Since October 2006, the so-called Infrastructure Act, which has been passed by the German Federal Government, regulates that these costs will not have to be carried by the investor, but by the grid operators, just like it is arranged with conventional power stations as well. This results in considerable cost savings for the operators of all offshore wind energy turbines that will be constructed before the 31st of December 2011.

In 2008, the erection of the first offshore wind farm project has been started in Germany: the test project alpha ventus near the island of Borkum. REpower will install there six 5M in 2009. The 5M serial production has begun in autumn 2008 in the new construction hall in Bremerhaven. In the future, the REpower 6M with six megawatts effective power will also be constructed there, its prototype will be erected at the German-Danish border in 2008.

The Beatrice project
REpower is participating in the "Beatrice Demonstrator Project" to test the performance of the 5 megawatt turbine on the open sea and to take a step closer to achieving its goal of making wind energy competitive. Two 5Ms have been installed near the Beatrice oil field in Moray Firth, 25 kilometres off the Scottish East coast and at a water depth of over 40 metres. The demonstrator project is part of the EU-supported "DOWNVinD" project, Europe's largest research and development programme in the field of renewable energies with a total volume of EUR 30 million. Talisman Energy (UK) and Scottish & Southern Energy (SSE) are the coordinators of the project, in which a large number of research and development organisations are participating from all over Europe. REpower is the exclusive turbine supplier.

The site of the Beatrice project

The completely installed wind farm, July 2007

More information on the project can be found at www.beatricewind.co.uk

You find a broad selection of pictures, amongst others on the Beatrice project as well as on the first six 5M in the Belgian wind farm Thornton Bank, on our online photo archive.