The first of 27 Vestas V174 – 9.5MW wind turbines has been installed at Parkwind’s Arcadis Ost 1 windfarm using a revolutionary technique
The turbine was installed by Heerema using one of the cranes on the floating heavy-lift vessel Thialf, using the rotor nacelle assembly (RNA) technique. The plan to use a floating installation method for Arcadis Ost 1 was first announced in November 2019. As highlighted by OWJ, the technique was tested at sea for the first time in October 2021.
This innovative way of installing wind turbines has two main advantages. The first is zero seabed interaction, which is important in areas of significant water depth or challenging soil conditions; the second is a shorter installation cycle.
To speed up the installation process, assembly and lifting operations happen in parallel. One of the Thialf’s two main cranes lifts the pre-assembled wind turbine generator-tower on to a pre-installed foundation. The vessel’s second crane was used to pre-assemble the wind turbine generator.
For the latter process, Heerema developed the RNA lift, which takes place on a ‘support tower’ on the crane vessel. The support tower provides a stable platform to allow for fast and secure assembly of the nacelle and the blades. Once pre-assembled the complete RNA is lifted as one piece onto the tower.
The reduced number of lifts between the vessel and the structure eliminates risks associated with floating installation. Vestas delivered RNA lift-ready components, developing new tools to support the offshore floating installation.
Parkwind co-chief executive Eric Antoons said, “The industry often talks about innovation. This is what our teams at Parkwind mean by it. Together with our partners we create solutions for challenges.”
Heerema Marine Contractors chief operating officer Michel Hendriks said, “This first installation using the RNA concept is the result of extensive engineering, innovation, and the dedication of our team, alongside Parkwind and Vestas, who worked hard to deliver the first floating installation of a wind turbine generator using our RNA method. This moment is also a major milestone within the offshore wind industry. Heerema will continue to develop and enhance our capabilities for the floating installation of offshore windfarms.”
Vestas senior vice president Flemming Ougaard said, “This innovative installation method promises to unlock the potential of many areas around the world with challenging soil conditions.”
Arcadis Ost 1 is a 257-MW windfarm developed by Parkwind in German territorial waters in the Baltic, northeast of the island of Rügen. It is the first European windfarm to use the Vestas V174-9.5MW turbines and Parkwind’s first international project. The installation campaign started in June 2022 and the windfarm is due to be commissioned in 2023.
