Van Oord, which recently started installing monopiles at the Ecowende offshore wind farm in the Netherlands, will soon deploy two pieces of equipment that allow monopiles to be installed using vibration technology and minimise noise disturbance for underwater life. The technology will be used during installation work at selected locations.
Van Oord’s offshore installation vessel Boreas began construction at the project site, owned by a consortium of Shell, Eneco and Chubu Electric Power, on 3 December.
CAPE Holland will supply and operate the CAPE Vibro Lifting Tool (CAPE VLT), specifically its VLT-640 Quad, which Van Oord will use to drive the monopiles into the seabed from the Boreas installation vessel at six selected test locations.
CAPE Holland’s technology uses vertical vibrations to temporarily reduce soil resistance, allowing monopiles to sink under their own weight.
“In the Dutch North Sea, the relatively dense sands present a major challenge to install the monopile by vibro-driving – making the Ecowende project an ideal setting to assess the capabilities of vibro-based methods in the most demanding ground conditions” , the Ecowende consortium says.
At three of the test locations, Can Oord will also utilise GBM Works’ VibroJet, including the Vibro Technology. This approach combines vertical vibrations with controlled water jets inside the monopile, fluidising the soil inside the monopile to further lower soil resistance. This increases the likelihood of achieving full depth while potentially generating lower underwater noise than conventional impact hammers, according to Ecowende.
“Noise regulations for offshore wind projects are becoming increasingly strict, while wind turbines continue to grow and monopiles become heavier, generating more underwater noise”, said Dick van Wijngaarden , Business Development Manager at CAPE Holland. “Vibro Technology has already demonstrated its capability and significant ecological benefits in commercial projects, but we need to fully understand how the technology performs in dense to very dense soils to apply it reliably and effectively and to continue its development for future projects.”
The combination of Vibro Technology with VibroJet Technology represents an important step toward reliably installing monopiles to full depth with minimal noise generation, according to Hein van Opstal, Business Development Director at GBM Works.
The utilisation of the technology will allow researchers to compare these approaches with traditional impact hammer installations and measure differences in performance, pile stresses, and noise generation. Data collected will also validate predictive models for underwater sound and pile behaviour, supporting broader adoption of low-noise techniques in future wind farms worldwide, Ecowende says.
At the Ecowende site, located approximately 53 kilometres off the Dutch coast near IJmuiden, Van Oord will install 52 monopile foundations produced by Sif and Smulders, which will support 52 Vestas V236-15.0 MW wind turbines.