Deutsche Bucht offshore wind farm is being constructed in Germany’s Exclusive Economic Zone (EEZ) of the North Sea. Northland Power, a Canadian power company, is developing the 269MW wind farm with an investment of €1.4bn ($1.6bn).
Construction works were started in September 2018 with the installation of the first steel foundation of the wind farm. Installation of 31 out of the 33 wind turbines on monopiles was finished in January 2019, while the project is expected to be commissioned in the second half of 2019.
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The wind farm is expected to produce sufficient renewable energy to supply to 328,000 German households.
Deutsche Bucht offshore wind farm make-up
The Deutsche Bucht wind farm is situated 100km away from the German main land and 95km from Borkum Island. It extends over 22.6km² in the EEZ where the average depth of the water is 40m.
The wind farm will feature 33 MHI Vestas V164-8.0MW turbines with a rated output of 8.4MW in power mode. Each turbine will feature three rotor blades of 80m-long each. The hub of the wind turbine will be 100m above the water level while the average length of the monopile will be 78m.
Foundations of the wind turbines will comprise 1,100t monopiles with a diameter of 8m at the bottom, which narrows down to 6.5m at the top.
Details of the Deutsche Bucht mono bucket pilot demonstrator project
The Deutsche Bucht wind farm will use mono bucket foundation structures for two of the 33 wind turbines to produce a collective output of 16.8MW.
The innovative technology, which was approved by the Federal Maritime and Hydrographic Agency of Germany (BSH) in May 2018, will be used for the first time for commercial operations in the Deutsche Bucht project.
The 61m-tall mono bucket will weigh 1,100t and will feature a steel cylinder-like structure called suction bucket, which will be pressed hard to be firmly embedded into the sea bed.
Power transmission and grid connection
The electricity generated by the wind farm turbines will be transmitted to the offshore substation using 52km of medium-voltage cables (33kV).
The 33kV power generated will be stepped-up to 155kV at the 4,500t offshore substation following which it will be transmitted to the 800MW BorWin beta converter station by grid operator TenneT.
The power will be further converted at the Diele onshore converter station before being integrated to the national grid.
Financing
Northland Power has raised €988m ($1.16bn) in debt capital financing from ten international commercial banks for the offshore wind project, in August 2017.
KfW IPEX-Bank acted as mandated lead arranger as well as facility agent for the transaction.
Contractors involved
MHI Vestas Offshore Wind Germany is the supplier of wind turbines for the Deutsche Bucht offshore wind farm. It will also provide operation and maintenance services for a period of 15 years.
Northland Deutsche Bucht has engaged K2 Management to provide construction management services for the wind farm, while Green Giraffe supported the demo project contracting and financing.
Van Oord was engaged as the general contractor and is responsible for all the balance of plant (BoP) works. The contractual scope includes installation of offshore transformer substation, foundations, and inter-array cables.
The joint venture of Iemants-Eiffage was engaged for the manufacture of the offshore substation of Deutsche Bucht, while Seaway Heavy Lifting is responsible for the installation.
Seajacks was awarded the sub-contract for transporting the components on the jack-up installation vessel Scylla, which was supplied by Oleg Strashnov.
Van Oord has sub-contracted EEW special pipe constructions (SPC) for the manufacture of monopiles, while the joint venture between Idesa and Windar Renovables was awarded the sub-contract for manufacturing transition pieces.
Universal Foundation is the designer of the mono buckets, while SiF and Harland & Wolff were awarded the subcontracts for manufacturing the same.
Norddeutsche Seekabelwerke was awarded the contract for the manufacture and supply of inter-array cables for the Deutsche Bucht offshore wind farm.
