In the next few days, one of the world’s largest floating cranes from Heerema Marine Contractors, named Thialf, will install the first foundations at EnBW’s 960 MW offshore wind farm, being built in German North Sea.
The He Dreih wind farm is being built roughly 85 kilometers northwest of Borkum and about 110 kilometers west of Helgoland. More than 500 employees will work on this large construction site in the middle of the sea at peak times.
Over 60 ships are involved in the construction of the project, with EnBW’s offshore office in Hamburg coordinating the work.
The Thialf, one of the world’s largest floating cranes, will install the first foundations in the seabed in the next few days.
A monopile – a 70-meter-long steel foundation 9.2 meters in diameter and weighing around 1,350 metric tons – will be used, upon which a transition piece will be placed, which serves as a connecting element between the tower of the wind turbine and the monopile.
The monopiles and transition pieces had previously been loaded onto floating platforms in Eemshaven in the Netherlands and towed to the construction site by tugboats.
Work on installing all of the foundations will continue into the summer, according to EnBW.
The wind turbines and cables are being manufactured at the same time. These will be installed and laid in early 2025.
The latest generation of 15 MW wind turbines from Vestas will be used. One single rotation of turbine rotor is enough to supply four households with electricity for a day.
The entire wind farm is scheduled to go into operation at the end of 2025. EnBW will be responsible for the technical and commercial management. Servicing and maintenance work will be carried out from its service base in Emden.
The Dutch-German grid operator TenneT will connect the wind farm to the grid using an offshore converter station and two high-voltage DC export cables.
The cables will be laid over a distance of 120 kilometers underwater and 110 kilometers on land. From the landfall point near Hilgenriedesiel, the electricity will be transmitted by buried cable to the future Garrel/Ost converter station in the Cloppenburg area.
A partner consortium made up of Allianz Capital Partners, AIP and Norges Bank Investment Management owns 49.9% of the shares in He Dreiht.
“After seven years of intensive planning, we are delighted that we are now able to start construction work. The successful development of a project on this scale once again demonstrates the ability of our offshore team to realize cost-efficient offshore wind projects in Germany and Europe. The expansion of offshore wind energy is an important part of our ongoing strategy to considerably increase our installed renewable capacity from 5.7 GW to 10 to 11.5 GW by 2030," said Peter Heydecker, Board Member for Sustainable Generation Infrastructure.