Jan De Nul Group Installing 72 Offshore Wind Turbines Offshore Denmark

For the largest offshore wind farm in Denmark, Jan De Nul Group is installing a total of 72 wind turbines of 8.4MW each on behalf of Vattenfall Denmark. All together, these turbines will produce enough green electricity for the annual needs of approximately 600,000 Danish households. Today, Jan De Nul is halfway: 36 windmills to go.

On January 27, Jan De Nul, Siemens Gamesa and Vattenfall successfully installed the very first wind turbine for the Kriegers Flak offshore wind farm. The last turbine is scheduled to be installed in mid-June, approximately 4.5 months after the start of this installation campaign.  

This offshore wind farm will become the largest in Denmark and will increase Denmark's offshore wind production by no less than 16 percent.  

Bert Reynvoet, Project Manager of Jan De Nul Group for the Kriegers Flak offshore wind farm: "We are proud that we can tick off this milestone nicely on schedule. All 72 wind turbines must be installed within a period of 4.5 months. Our customer's wishes are paramount and despite the challenging winter weather conditions in the Baltic Sea, COVID-19 and challenging soil conditions for our jack-up installation vessel, we have managed until today to strictly adhere to the installation schedule. Thanks to the commitment, flexibility and professionalism of our co-workers!”   

Roenne as marshalling harbor  

For the first time since its expansion in 2018, the port of Roenne on the Danish island of Bornholm is serving as marshalling harbor for the construction of an offshore wind farm.   

The components of the Siemens Gamesa wind turbines are delivered from Denmark’s mainland. In Roenne, the various parts are assembled. In sets of four wind turbines, they are loaded on board Jan De Nul’s jack-up installation vessel Vole au vent, after which the vessel sails to the offshore installation site off the Danish east coast.   

Bert Reynvoet: “When a large installation vessel like the Vole au vent enters a port for the first time, it is always a bit exciting. Moreover, it was new for everyone involved, but thanks to the top service of the port and our local partners, Roenne turns out to be a perfect marshalling harbour. An absolute boost in these challenging times.”  

Long-term cooperation  

In 2017 and 2018, Jan De Nul Group already designed, built and installed two large Gravity Based Foundations for the offshore high-voltage substations of this new offshore wind farm.   

Jan De Nul built both concrete structures of 8,000 and 10,000 tonnes on a floating pontoon in the port of Ostend (Belgium) and then tugged them to Denmark. In the Baltic Sea, the crane vessel Rambiz installed both foundations on the seabed with the utmost precision. 

About the Kriegers Flak offshore wind farm   

§  600 MW will be the total production capacity, which equals the annual electricity needs of about 600,000 Danish households.  

§  72 wind turbines of 187 meters high will cover an offshore area of 132 km² at 15 to 40 kilometers off the Danish East coast.  

§  About 170 kilometers of subsea cables will be installed to connect the offshore wind farm to the Danish grid.   

§  The wind farm is expected to be fully operational by the end of 2021.