Adaptation of annex 2 of TenneT’s Commitment to account for the commissioning of the East Coast Line

In compliance with TenneT’s Commitment to the European Commission (“Commitment”) (Commission Decision of 7.12.2018 […] Case AT.40461 – DE/DK Interconnector), TenneT guarantees a certain minimum transmission capacity at the bidding zone border of /Luxembourg (“DE”) and Denmark West (“DK1”), referred to as Guaranteed Hourly NTC. According to recital 46 (i) of the Commitment, TenneT may reduce the Guaranteed Hourly NTC to what is necessary and proportional to comply with safety standards of secure network operation if critical transmission lines (listed in Annex 2 of the Commitment) are not available due to unplanned outages, construction or maintenance work; but not below a threshold of 500 MW (hereafter referred to as Minimum Threshold).

Following the commissioning of the East Coast Line the list of critical transmission lines of annex 2 of the Commitment and the Minimum Threshold have to be adapted and aligned with the Monitoring Trustee. Subsequently, the adaptation has to be published on the website of TenneT no later than 1 January following the commissioning of the East Coast Line. The Monitoring Trustee shall in this respect provide a report to the European Commission with his opinion on the appropriateness of the amendments.

Although TenneT has no process planned or implemented to apply reductions of the Guaranteed Hourly NTC in case of unplanned outages, construction or maintenance work in accordance with Annex 2 of the Commitment, the determination of the Minimum Threshold and the list of critical transmission lines shall be adapted as required by the Commitment.

Therefore, the Minimum Threshold and the list of critical transmission lines have been adapted to account for the commissioning of the East Coast Line. As of 1 January 2021 the Minimum Threshold will be increased to 1300 MW and the list of critical transmission lines defined in Annex 2 of the Commitment will be changed as .follows. The updated list is shown in Table 1. • Both 380 kV lines Audorf – are rerouted via to Audorf Süd • Both 220 kV lines, Flensburg – Kassoe and Flensburg – Ensted have been decommissioned • Two 380 kV lines originating from Audorf Süd to Kassoe via Handewitt and West have been commissioned.

Table 1: Updated list of relevant critical transmission lines of annex 2 of the Commitment

EIC Name 10T-DE-DK-00001I 380-kV-Stromkreis Jardelund - Kassoe/ENDK 1 10T-DE-DK-00002G 380-kV-Stromkreis Jardelund - Kassoe/ENDK 2 11T0-0000-0926-V 380-kV-Stromkreis Handewitt - Jardelund blau 11T0-0000-0925-Y 380-kV-Stromkreis Handewitt - Jardelund grün 11T0-0000-0924-0 380-kV-Stromkreis Audorf Süd - Flensburg - Handewitt blau 11T0-0000-0923-3 380-kV-Stromkreis Audorf Süd - Flensburg - Handewitt grün 10T1001C--00063U 380-kV-Stromkreis Handewitt - Kassoe/ENDK 1 10T1001C--00064S 380-kV-Stromkreis Handewitt - Kassoe/ENDK 2 11T0-0000-1471-8 380-kV-Stromkreis Schuby West - Handewitt rot 11T0-0000-1472-5 380-kV-Stromkreis Schuby West - Handewitt gelb 11T0-0000-1473-2 380-kV-Stromkreis Audorf Süd - Schuby West weiss 11T0-0000-1475-X 380-kV-Stromkreis Audorf Süd - Schuby West schwarz

Figure 1 shows the changes by comparison of the grid topology at the border DE-DK1 valid until 8 June 2020 before (left), and after the commissioning of the East Coast Line valid from 14 July 2020 (right). Each change is marked by a designated number, indicating whether a segment has been commissioned (green) or decommissioned (red).

Figure 1: Comparison between the grid topology before (left side) and after (right side) the commissioning of the East Coast Line

Starting on 8 June 2020 the 220 kV interconnector line leading from Flensburg to Kassoe was decommissioned (1). On 22 June 2020 the first out of two lines connecting Handewitt and Schuby West was commissioned, followed by the second line on 23 June 2020 (2). On 1 and 2 July 2020 respectively two interconnector lines connecting the substations Handewitt and Kassoe have been commissioned (3). By 14 July 2020 two lines between Audorf Süd and Schuby West (4) were commissioned, representing the completion of the East Coast Line. Finally the remaining 220 kV interconnector line between the substations Flensburg and Ensted was decommissioned on 3 August 2020.