Start assembly 11MW Siemens Gamesa wind turbines on Maasvlakte

The foundation installation campaign of wind farm Hollandse Kust Zuid is taking a scheduled winter break. But behind the scenes of the world’s biggest and first subsidy free offshore wind farm, the production of the wind turbine parts is moving quickly. At the start of this year, Vattenfall and wind turbine manufacturer Siemens Gamesa reached a new milestone: the first full serial production nacelle was completed at the production site in Cuxhaven, Germany. This month, the first turbine parts are scheduled to be transported to Maasvlakte in the Netherlands. Here, Siemens Gamesa is assembling the different wind turbine parts from all over Europe before the first installation onto the monopiles this spring.  

Last year, the Hollandse Kust Zuid team was mainly focused on the start of the offshore construction of the foundation monopiles. After years of preparation the installation vessel took its first trip to the North Sea to start construction in July 2021. At the same time, the Vattenfall and Siemens Gamesa teams were working together to ensure that the other parts of the wind turbines were designed and manufactured as scheduled, and according to the highest standards. At the beginning of this year, they reached a new milestone; the completion of the first full nacelle – the top part of the wind turbine that houses components like the generator – in Cuxhaven, Germany.

Vattenfall’s Wind Turbine Package Manager Kevin Metcalfe on how the highest quality, safety and performance standards of the nacelles are guaranteed: “Vattenfall and Siemens Gamesa agreed to build some pre-production test nacelles at a separate facility. A prototype turbine has also been running for over a year in Denmark to further ensure the best design and highest performance standards for Wind Farm Hollandse Kust Zuid. We took those early learnings and incorporated them into the final design. This extensive testing and a great collaboration between Vattenfall and Siemens Gamesa led to the successful first production at Cuxhaven.”

Transportation to Maasvlakte

The nacelles for the 11MW wind turbines are transported from the production site in Cuxhaven to Maasvlakte near Rotterdam by ship over the North Sea. At Maasvlakte, a site was made ready to receive all the parts and prepare them for transport to the offshore site. Even though Wind Farm Hollandse Kust Zuid is built in Dutch waters, it is also a European project. The 97 meters long blades are in continuous production at Aalborg, Denmark. The tower production is ongoing at several sites in Denmark, Spain and Portugal. “Production is going well at sites across Europe”, Kevin says. “The actual installation of the turbines will start mid-April 2022 and will carry on in a continuous campaign of four turbines per trip, until completion in early 2023.”

Four turbines per trip

After transporting the parts across Europe to the Maasvlakte, Siemens Gamesa assembles the tower sections into a complete tower with internal electrical equipment and prepares it for loadout to the installation vessel with the nacelle and blades*. Kevin: “To transport the complete turbines to the foundation in the North Sea we use the Wind Osprey installation vessel, provided by Cadeler. This jack up vessel is mobilized with project specific equipment to transport and install the turbine components. A set of components for four complete turbines will be loaded from the Maasvlakte onto the installation vessel each trip.”

Once loaded and secured the installation vessel sails the short trip to the Hollandse Kust Zuid offshore site. When in the right position next to the foundation, the installation vessel jacks up to form a stable working platform. The complete tower will be lifted over from the installation vessel to the installed monopile and bolted in place. The nacelle follows and is placed on top of the tower before the individual installation of the three blades.

Offshore preparations

At the Hollandse Kust Zuid offshore site, preparations are made for the arrival of the complete turbines. The first 34 foundations were already installed, while the remaining foundations are to be installed during the second installation campaign starting in April. The installation of the first wind turbines runs at the same time as the installation of the last foundations. Seabed surveys and the clearance of any unidentified objects made sure that installation vessels and cable installation can work and be done safely.

The first turbine is expected to be commissioned and producing clean renewable electricity by early May 2022. The other turbines will be subsequently installed and running one after another in a continuous campaign until finalization of the wind farm in 2023. Once in operation, Wind Farm Hollandse Kust Zuid will be the world’s biggest and first subsidy free wind farm.

*De assembly location can be spotted on the FutureLand webcam at the Maasvlakte nearby Rotterdam:

First SG 11.0-200 DD Nacelle in Cuxhaven. Credits: Siemens Gamesa

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Vattenfall generates and supplies electricity, heating, cooling and gas as well as offering customers a variety of sustainable solutions. Vattenfall want to achieve fossil-free energy generation within one generation. This Swedish energy company is investing heavily in wind energy to achieve this aim. We are working towards a sustainable world, for now and in the future.