The Offshore Wind Farm, Merkur Offshore is located in the German Exclusive Economic Zone (EEZ) in the North Sea, about 45 km north of Borkum Island in the north-eastern part of the specified zone for offshore wind farms. The project site covers an area of 47 km². Merkur Offshore will be equipped with 66 wind energy converters of GE’s offshore wind turbine “Haliade 150” with a rated power of 6 MW each. The hub height of a single turbine is more than 100m above water level and the gearless 6-MW machine is equipped with 150-m diameter rotors, one of the largest in the wind industry.
EWE Offshore Service & Solutions GmbH (EWE OSS) won a contract to provide technical maintenance of the Merkur offshore substation in the German North Sea. The substation will collect the electricity generated at the 396-MW wind farm and feed it into the German grid.
Haliade 150-6MW owes its name to the mythical Greek, “Heliades”: the nymphs of seas and oceans. The Wind Turbine Generator (WTG) has been designed following Class I-B specifications of the standards IEC-61400-1/IEC-61400-3. It is suitable for offshore sites with a reference wind speed of 50 m/s (10-min average) and a 50-year extreme gust speed of 70 m/s (3-sec average).
The Haliade 150-6MW is a 3-bladed upwind design, operating at variable speed. It is equipped with a permanent magnet direct-drive generator and three identical full power converters. The converters and transformer are located at the tower bottom, along with a low voltage electrical-distribution cabinet. A distribution cabinet is placed in the nacelle to supply the pitch, the yaw, and cooling fans in the nacelle, and to collect signals from the sensors.
Due to the rough ambient conditions in offshore environments, an air conditioning system will control the inside air quality and protect components against corrosion and high temperatures. In addition, the main wind turbine components are cooled by heat exchangers.
“With EWE OSS, we have a reliable and experienced partner for the maintenance and repair of the substation at our side. This marks another significant milestone on the way to the commissioning of the entire wind farm by the end of 2018,” said Arjen Schampers, Managing Director of Merkur Offshore GmbH, the developer of the wind farm.
The two companies are said to be discussing further areas of cooperation as well.
EWE OSS plans to use the proximity of its existing projects, Alpha Ventus and Trianel Windpark Borkum, to create synergies and provide a cross-project logistics and maintenance support. The wind farm’s offshore substation was installed on site in January 2018.