Monitoring, Offshore, Wind Power

Nordex Going Offshore with Elsam

At the end of April, Nordex will be installing an N90 offshore wind turbine at a test field off the Danish port of Frederikshavn in North Jutland. The owner of the test field is Danish utility Elsam, which also operates the nearby offshore wind farm Horns Rev.

Hamburg, Germany – April 9, 2003 [SolarAccess.com] Preparations for installing the turbine have already been completed at the location, with the foundation sunk into the seabed of the Kattegat in March. This is a heavy-duty foundation tied to the seabed by means of planking and piles. The 2.3 MW turbine is based on the 2.5 MW N80 series which Nordex has been building for large international customers for more than three years. However, the offshore version has a number of technical modifications. For example all the electrical systems, such as the transformer, voltage converter and the controller, are integrated in the nacelle. Dehumidifiers ensure that the sensitive electronic systems are not damaged by the effects of high levels of humidity. At the same time, the turbine mechanics are protected from corrosion. Nordex has also taken preemptive steps to avert technological risks: the gear system is fitted with an enlarged oil filter, while a central lubrication system automatically keeps the bearings and gears well lubricated. Moreover, the turbine is equipped with redundant oil and air-cooling circuits. In this way, Nordex has been able to extend the service intervals for these components from six to twelve months. The offshore turbine also features a condition monitoring system allowing preemptive maintenance by recording the noise, temperature and vibration of the wear-prone components and systems on the basis of a comparison between actual and required readings. In this way, Nordex can replace components exhibiting signs of fatigue during standard maintenance operations to avoid non-scheduled downtimes. This year, Nordex will also be installing a N90 offshore turbine in the River Breitling off the port of Rostock in conjunction with WIND-projekt Ingenieur- und Projektentwicklungsgesellschaft for a local operator. Using this turbine, the customer intends to gain preliminary experience for its planned offshore wind farm. At the same time, the Company has already signed a delivery agreement with Offshore Ostsee Wind AG for the first wind farm inside the 12-mile zone off the coast of Mecklenburg-West Pomerania. Comprised of turbines in the 2 MW to 3 MW class, the Baltic 1 wind farm is to be assembled as of summer 2004. The turbines alone are worth €50 million (US$53.5 million). Given the water depth of approximately 18 meters and the substantial distance from the land-based grid feed-in point, the planners have budgeted total costs of €120 million (US$128.4 million). However, the high mean wind speed and low turbulence will ensure that the wind farm operates efficiently.