Invitation to technical dialogue regarding the soft seabed found at the site for Hesselø Offshore Wind Farm

8. October 2021
Figure: Danish Energy Agency.

The Danish Energy Agency (DEA) and Energinet invite potential developers to dive into the seabed-data and to contribute with their assessment of whether Hesselø OWF is still attractive to establish within the current framework set for the project.

Before the summer, the tender for Hesselø OWF was put on hold as the results of Energinet's preliminary investigations had revealed soft clay formations 20-30 m below the seabed at the site for Hesselø OWF located 30 km. north of Zealand in the Kattegat.

The DEA has just published the report and associated data from the preliminary geophysical investigations, which can now be found at This will be followed by a draft report and data from the preliminary geotechnical investigations, expected to be published at the end of October.

The processing of data from the preliminary investigations has now reached a point where the DEA and Energinet can invite potential developers to a technical dialogue to discuss whether the seabed conditions challenges the establishment of Hesselø OWF within the politically agreed framework e.g. in relation to subsidy scheme, the target capacity of 800-1,200 MW, the planned time of completion, etc.

Virtual technical dialogue from late October to late November

The technical dialogue will be virtual and take place from late October to late November 2021. 

For more details on the timetable for the dialogue and on how to participate, please see the Program for the Technical Dialogue for Hesselø Offshore Wind Farm.

Based on the input provided by the potential developers as well as further analyses, the DEA will assess whether the tender for Hesselø OWF can continue under the current framework.

If new political decisions are required in order to move ahead with Hesselø OWF, the parties behind the 2020 Climate Agreement for energy and industry must re-assess whether the Hesselø OWF site is still the preferred solution or whether the second OWF mentioned in the 2018 Energy Agreement should instead be established at an alternative site.


  • Hesselø OWF is to become “park no. 2” from the 2018 Energy Agreement in which it was decided to establish three new large-scale OWFs of at least 800 MW by 2030, with Thor OWF being the first park.
  • With the Climate Agreement on energy, industry, etc. from 2020, it was decided to place park no. 2 in the Kattegat, 30 km. north of Zealand and approx. 20 km. from the island of Hesselø.
  • In the Climate Agreement, it was also decided to advance the time schedule for Hesselø OWF with completion in 2027, at the same time as Thor OWF.
  • In October 2020, Energinet started the preliminary investigations at sea.
  • In June 2021, the tender process for Hesselø OWF was put on hold after Energinet's preliminary investigations showed soft clay formations below the seabed in large parts of the area
  • Read the terms of subsidy model agreed for Hesselø OWF.


Project manager Therese Kofoed Jensen,, + 45 33926810


Ture Falbe-Hansen
Head of Press (+45) 2513 7846

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