The bidding zone border DE/LU-DK2 is comprised of the two interconnectors "KONTEK" and "Kriegers Flak Combined Grid Solution (KF CGS)" and is assigned to the capacity calculation region (CCR) Hansa. Calculation of the transmission capacity available for electricity trading between the bidding zones DE/LU and DK2 is regulated by the corresponding capacity calculation methods of the CCR Hansa. The special features of the two interconnectors KONTEK and KF CGS described below are taken into account therein.
To calculate the available transport capacity for the KONTEK link, an HVDC transmission line with controllable active power transfer, we only take into account the provision of grid losses. Grid losses occur each time electricity is transmitted as a result of the energy needed for the transport itself. The energy required to cover the grid losses on the KONTEK link is provided in eastern Denmark, regardless of the direction of the load flow. Specifically, 2.5 % (15 MW) of the capacity is required for the transmission of the grid losses and therefore cannot be made available to the market. Under normal operating conditions, the transmission capacity made available for electricity trading is therefore 600 MW in south-north direction and 585 MW in north-south direction.
The model approved by the German regulatory authority to calculate the total transmission capacity on the KONTEK link can be found under the following link:
Model to calculate the transmission capacity on KONTEK (in German) (Download PDF, 76,1 KB)
The interconnector KF CGS started its commercial operation on 15.12.2020. The connection represents a technical novelty, as an interconnector and national connections of offshore wind farms have been combined here for the first time (details can be found on the KF CGS project website). Therefore, when calculating the transmission capacity available on KF CGS for electricity trading between the bidding zones DE/LU and DK2, the electricity feed-in to be expected from the integrated offshore wind farms must be considered. These technical specificities are also taken into account by the decision of the EU Commission of 11 November 2020 to grant a derogation to KF CGS pursuant to Article 64 of Regulation (EU) 2019/943. This derogation stipulates that only that part of the interconnector capacity of the KF CGS can be used for electricity trading which is not required to transport the electricity generated by the integrated German and Danish offshore wind farms to the respective national transmission grids. Accordingly, the basis for the calculation of the minimum capacity pursuant to Article 16 (8) of Regulation (EU) 2019/943 is the remaining capacity of KF CGS after deduction of the capacity required to transport the electricity feed-in from the connected wind farms to the respective national transmission systems as forecasted day-ahead.
During operation the physical power flow on KONTEK and KF CGS is optimized aiming among other things at a minimisation of the incurring grid losses. 50Hertz and Energinet are currently researching whether changes in the provision of the grid losses are economically reasonable. Should this be the case, 50Hertz and Energinet will make appropriate adjustments after consultation with the German and Danish regulatory authorities and after timely prior notice.
Furthermore, due to scheduled works or disturbances in the transmission grids of 50Hertz and/or Energinet, the available transport capacity in the relevant transmission grid may be restricted. As a result, limitations of the transmission capacity available for the market between the bidding zones DE/LU and DK2 can occur.