Jan De Nul Group installs 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.
Approximately 4.5 months after the start of this installation campaign in January, Jan De Nul, Siemens Gamesa and Vattenfall deliver the 604 MW Kriegers Flak offshore wind farm.
Bert Reynvoet, Project Manager of Jan De Nul Group for the Kriegers Flak offshore wind farm: "Our project team, crew members on board the Vole au vent and all our partners involved did a fantastic job. Despite the winter weather conditions and extra challenges due to COVID-19, the works have always been on schedule, thanks to their efforts. Great teamwork! We are very proud to have helped Denmark in this giant leap in their energy transition.”
The Kriegers Flak offshore wind farm is the largest in Denmark and increases Denmark's wind production by no less than 16 percent.
Challenging soil conditions for a Jack-Up vessel
The geographical location of the offshore wind farm offers extremely heterogeneous soil conditions with large lateral variability and boulders on the surface and below. Despite that, Jan De Nul managed to successfully deploy a Jack-Up Installation Vessel for the installation works.
Bert Reynvoet: “Thanks to elaborate preliminary geophysical and geotechnical studies and with the help of an in-house calibrated leg penetration model, we managed to engineer an efficient jacking procedure. This allowed us to execute the project ahead of schedule.”
Offshore high-voltage substations
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 towed 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
§ 604 MW is the total production capacity, which equals the annual electricity needs of about 600,000 Danish households.
§ 72 wind turbines of 187 metres high cover an offshore area of 132 km² at 15 to 40 kilometres off the Danish East coast.
§ About 170 kilometres of subsea cables connect the offshore wind farm to the Danish grid.
§ The wind farm is expected to be fully operational by the end of 2021.
About Jan De Nul Group
Design. Build. Connect. Jan De Nul Group shapes water and land. Worldwide. From complex services to the offshore energy and energy transition sector, over large dredging and defence works on the edge of water and land, to challenging civil and environmental works. Well integrated competences and investments lead to creative, sustainable and innovative solutions. In this way Jan De Nul Group delivers results that produce satisfied customers.