|Nacelles for the Alpha Ventus offshore wind farm ready for transport to the site.|
REpower Systems AG has erected the first of a total of six REpower 5M turbines for the alpha ventus offshore test field. The systems each have a rated power of five megawatts, with a blade tip height of 155 meters above sea level. The first German offshore project is being built by a consortium of companies consisting of EWE, E.ON and Vattenfall. The alpha ventus offshore wind farm is located approximately 45 kilometers north of the island of Borkum.
At the beginning of September, the world’s largest crane ship “Thialf” anchored six jacket foundations onto previously erected piles in water around 30 meters deep. On one of these lattice structures, which are especially suitable for great water depths, the first REpower turbine was erected. Five additional wind energy turbines are scheduled to be installed by the end of the year. “We expect that the first turbine will supply power to the electricity grid in the fourth quarter of this year,” reported Norbert Giese, Offshore Director of REpower Systems AG. “Of the 18 REpower 5M wind turbines already erected, we now have successfully installed nine on the open seas, each in water up to 45 meters deep. REpower therefore continues to be the market leader in the sector of multi-megawatt offshore turbines and for installations in deep waters away from the coast.”
Wilfried Hube, General Project Manager for alpha ventus, added: “We are pleased to be working together with REpower in this section of the project to erect the first 5M turbine now in German territorial waters. Now that the first six wind energy turbines are already being placed into operation, we’re in the final sprint to finish the wind farm by the end of the year.”
The REpower 5M turbines have been specially developed for offshore installation. “We’ve placed a great emphasis on serviceability, for example. The components are generously designed and the turbines are intended to be serviced just once per year later,” according to Giese. With optimum wind conditions, each of the six turbines is slated to supply the electricity grid with around 18 million kilowatt hours (kWh) of power per year. All together, the alpha ventus wind farm will generate enough power to meet the annual power requirements of around 50,000 households. Before erection on the open seas, the hub and three rotor blades were first preassembled in the Dutch base harbor of Eemshaven to form a rotor star. Afterwards, all components of the first wind energy turbine – that is, two tower segments, one nacelle and the rotor star – were transported to the offshore construction site by means of a jack-up barge.
A new regional development plan was recently approved by the German federal cabinet. The resolution calls for the erection of 30 wind farms in the North Sea as well as ten additional wind farms in the Baltic Sea. In total, the planned projects are targeted to have a capacity of around 12,000 MW, thus helping to achieve the climate protection targets of the Federal Government, which envisage that the percentage of power supplied by renewable energy will be increased to 30% by 2020 and around 25,000 MW of power will be supplied from offshore systems by 2030.
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