Kriegers Flak Offshore Wind Farm is a 605MW wind power project being developed at Kriegers Flak in the Baltic Sea, approximately 15km off the coast of Denmark. It will be the biggest wind farm in Denmark as well as in the Baltic Sea, upon completion.
Swedish state-owned power company Vattenfall won the tender to build the wind farm with a bid of £44.8 (€49.9) per MWh, in November 2016. It was the world’s lowest ever bid for an offshore wind power project at that time.
The Kriegers Flak offshore wind project is estimated to cost up to £1.1bn (€1.3bn). Vattenfall took the final investment decision (FID) on the project in December 2018.
Construction works for the project were initiated with the start of manufacturing of the monopile foundations for the wind turbines in May 2019.
The Kriegers Flak offshore wind farm is expected to be fully operational by the end of 2021.
It will generate enough electricity to power 600,000 Danish homes over its estimated lifespan of 25 years.
Kriegers Flak offshore wind farm make up
Kriegers Flak offshore wind farm will comprise two sections namely Kriegers Flak A (west section) and Kriegers Flak B (east section), which will have installed capacity of approximately 200MW and 400MW, respectively.
In total, the Kriegers Flak offshore wind farm will use 72 Siemens Gamesa turbines of 8.4 MW capacity each.
Each turbine will have a tip-height of 188m and a rotor diametre of 167m and weigh 800t.
The electricity generated by the turbines will be transmitted via inter-array cables to two 220kV offshore substations.
Each section of the wind farm will have its own transformer platform. The distance between the two offshore substations will be 11km.
The first gravity-based foundation for the offshore transformer platforms of the wind farm was installed in February 2018.
Kriegers Flak grid connection details
The Kriegers Flak offshore wind farm will be interconnected with two German offshore wind farms namely Baltic 1 (48MW) and Baltic 2 (288MW).
The Baltic-2 offshore substation will be connected with one of the Kriegers Flak offshore substations through two 30km-long 150kV transmission cables.
Electricity from each of the Kriegers Flak offshore transformer platforms will be transmitted through a 44km-long 220kV submarine cable to the Danish coast at Rødvig on Stevns.
The electricity will be further transmitted from Rødvig to the 400kV Bjæverskov, Ishøj, and Hovegård substations in Denmark.
The project also involves the expansion of the existing Bjæverskov, Ishøj, and Hovegård substations.
Named as the Kriegers Flak-Combined Grid Solution (CGS) project, it is the first offshore interconnector project in the Baltic Sea linking transmission grids of two countries.
The interconnector project will allow electricity to be traded from Denmark to Germany and vice versa.
The combined grid solution project includes a back-to-back converter facility at Bentwisch near Rostock, Germany, for converting high-voltage direct current (HVDC) to alternating current (AC) and vice-versa.
The European Union (EU) has recognized the interconnection as a Project of Common Interest (PCI) and provided $168m (DKK1.1bn) of funding from the European Energy Programme for Recovery.
Power Purchase Agreement (PPA) for the Kriegers Flak wind farm
Novozymes, a global biotechnology company based in Denmark, and Novo Nordisk, a global pharmaceutical company also based in Denmark, signed long-term power purchase agreements (PPAs) with Vattenfall for the Kriegers Flak offshore wind farm in July 2018.
Contractors involved with the Kriegers Flak offshore wind farm project
Siemens Gamesa is the turbine supplier for the Kriegers Flak offshore wind farm. ABB supplies 100km of 220kV submarine cables as well as a back-to-back HVDC converter for the offshore wind project.
Jan De Nul Group was contracted for the installation of gravity-based foundations for the offshore transformer platforms.
EEW Special Pipe Construction will provide monopile foundations for the Kriegers Flak offshore wind turbines, while Bladt Industries will supply the transition pieces.
Van Oord Offshore will be responsible for the installation of monopiles and transition pieces.
German transmission operator 50Hertz is responsible for the construction and operation of the German section of the interconnector project, whereas its Danish counterpart Energinet is responsible for that on the Danish side.
JDR Cable Systems will supply the inter-array cables for the Kriegers Flak offshore wind farm, while installation will be performed by Global Marine.
Tekmar Energy, a subsidiary of Tekmar Group, was subcontracted by Global Marine to supply 150 patented TekLink® cable protection systems in January 2020.
It was also subcontracted by JDR Cables to supply 151 cable hang-off assemblies for the Kriegers Flak offshore wind farm in the same month.