North Sea, Germany
Deutsche Bucht offshore windfarm is currently under construction within Germany’s Exclusive Economic Zone (EEZ) of the North Sea by Northland Power, an independent power producer based in Canada.
With an installed capacity of 269MW, the windfarm will produce enough renewable energy to power 328,000 homes. It is expected to generate 1.1 billion kilowatt hours of energy a year once operational in 2019. Deutsche Bucht will be Northland Power’s third windfarm in the North Sea region.
Installation of steel foundations at the project site began in September 2018, marking the start of construction works. The €1.4bn ($1.6bn) windfarm is expected to be commissioned in the second half of 2019.
In August 2017, Northland Power secured €988m ($1.1bn) through non-recourse construction and term loan as well as other loan facilities arranged by ten international commercial banks for the windfarm.
Deutsche Bucht offshore windfarm location details
Located 100km away from mainland Germany and 95km north-west of Borkum Island, the windfarm is spread across 22.6km² area having an average water depth of approximately 40m.
The windfarm will be installed with 33 MHI Vestas V164-8.0MW turbines. Each turbine generator with a rated output of 8.4MW will be fitted with three rotor blades of 80m length each. The wind turbine’s hub will have a height of 100m above the water level, while the height of the monopile will be 78m. The transition piece of each turbine will measure 26m-long.
Foundations of the wind turbines integrate sturdy 1,100t monopiles with a diameter of 8m at the bottom and 6.5m at the top.
Two turbines of the windfarm are being installed on mono bucket foundation structures, making it the first of its kind in the world to use such a foundation for commercial operations.
The mono bucket foundation features a steel cylinder like structure known as suction bucket. A shaft is mounted on the suction bucket, which uses the vacuum created by the suction motor as well as its own load to penetrate into the sea floor, avoiding the need for pile driving.
Installation of 31 wind turbines on monopiles was completed in January 2019, while the remaining two wind turbines will be installed on mono bucket foundations.
The Federal Maritime and Hydrographic Agency of Germany (BSH) approved the installation of the two mono bucket foundations in May 2018.
Deutsche Bucht offshore windfarm substation details
The power generated by the windfarm will be stepped up from 33kV to 155kV by its own substation and will be transmitted to the BorWin beta offshore converter station via medium-voltage cables.
Cables measuring 52km-long to be laid for the windfarm can carry fibre-optic conductors and withstand corrosion and wear. Conductors will relay information between the turbines, substations, and control stations.
The offshore converter station will be connected to an onshore converter station at Diele through direct-current cables.
Electricity will be converted back at the onshore converter station before being fed to the German power grid.
MHI Vestas was contracted to supply turbines for the Deutsche Bucht offshore windfarm. The company is also responsible to provide operation and maintenance services for a period of 15 years.
Marine engineering and construction company Van Oord is responsible for the engineering, procurement, construction and installation of the balance of plant. The scope of work also includes transformer substation production and inter-array cables.
EEW Special Pipe Constructions (SPC) is responsible for the monopiles production, while a joint venture of Idesa and Windar Renovables provided transition pieces for the turbine poles.
K2 Management was contracted to deliver project management services during the construction phase. The mono buckets were designed by Universal Foundation.