Nominated Electricity Market Operators (NEMOs) and Transmission System Operators (TSOs) are prepared for a potential scenario where the United Kingdom leaves the EU without a deal on 31 October 2019.

Should this scenario happen, the consequence would be the removal of Great Britain (GB) from implicit day-ahead market coupling. In that case the last implicit allocation on BritNed, IFA and Nemo Link would take place on 31 October (D-1), for delivery date 1 November (D). The first explicit allocation for day-ahead capacity on the BritNed, IFA and NemoLink interconnectors would take place on 1 November (D-1), for delivery date 2 November (D).

Given the uncertainty around Brexit, NEMOs and TSOs have agreed to a solution for the scenario where the United Kingdom leaves the EU without a deal. The solution foresees the removal of the GB bidding zone and lines connected to it from SDAC.

The Single Electricity Market (SEM), which encompasses the island of Ireland, would remain within the implicit day-ahead market coupling with the SEM bidding zone operated in an isolated mode. This solution has been successfully tested during September.

Single Day-Ahead Coupling (SDAC) allocates scarce cross-border transmission capacity in the most efficient way by coupling wholesale electricity markets from different regions through a common algorithm, simultaneously taking into account cross-border transmission constraints, thereby maximising social welfare.

The aim of SDAC is to create a single pan European cross zonal day-ahead electricity market. An integrated day-ahead market increases the overall efficiency of trading by promoting effective competition, increasing liquidity and enabling a more efficient utilisation of generation resources across Europe.

For additional information on SDAC go to:

http://www.nemo-committee.eu/sdac
https://www.entsoe.eu/network_codes/cacm/implementation/sadc/