Growth through Research, development & demonstration in Offshore Wind


First offshore wind turbine using the Slip Joint connection successfully installed

30 september 2018

SJOR project tests innovative connection offshore: ready-to-use installation within an hour.

This morning the DOT wind turbine was successfully installed on its previously installed monopile using a Slip Joint connection. The Slip Joint is an alternative connection between an offshore wind turbine and its foundation. It works and looks like two paper cups upside down stacked on top of each other. The connection is based on friction, where the weight ensures a firm and stable connection. Installation is done by simply sliding the wind turbine over the monopile without the use of grout or bolts. This simple mechanism allows for cost reduction in material, equipment & personnel as well as allowing for a shorter installation time. It is the first time a slip-joint connection is deployed offshore. 

The DOT wind turbine is located in Eneco’s Princes Amalia Wind Park off the coast of IJmuiden, the Netherlands. The complete wind turbine was picked up in a single lift by Heerema’s DCV Aegir from the quay of Sif Rotterdam and transported towards its designated location. The installation of the wind turbine took within an hour in total, which is noticeably faster than usual installation. Jan van der Tempel, Director of DOT BV: “This offshore installation is a major milestone in the commercialisation of the Slip Joint.” The wind turbine will stay offshore for a year to test and collect data regarding this innovative connection after which the gathered data will be processed and used for validating lab tests by both TU Delft and TNO.

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Installation slip joint connection magnify
Installation slip joint connection
Installation of turbine with Slip Joint connection

David de Jager is GROW’s new Director

15 May 2018

As of today David de Jager succeeded Ernst van Zuijlen as Director of GROW. After being responsible for the programming of RD&D on offshore wind energy for about ten years (as Director of FLOW, TKI Wind op Zee, and GROW) Ernst will pitch into both product- and project development in the same area.

David de Jager comes from consultancy firm Ecofys and has almost 30 years of experience in renewable energy, notably on the interaction of technology development, policy design, and finance. Over the past decade he acted as Operating Agent for the IEA-RETD, an international research program of the International Energy Agency.

David de Jager
David de Jager

GROW consortium officially launched at Wind Days 2016

The GROW consortium was officially launched at the WindDays 2016 conference held in Rotterdam, the Netherlands. This consortium of leading Dutch companies and knowledge institutes involved in the offshore wind industry has created an innovation programme that aims to reduce the costs of offshore wind energy.

GROW launch during WindDays 2016
GROW launch during WindDays 2016