How will the Reference Day be applied during the SDAC 15-minute MTU rollback activation period if the Nordic-Baltic Regional Coupling cannot be performed before 20:00 CET?
With the SDAC 15-minute MTU go-live on 30 September 2025, situations can occur where the resolution of the Reference Day is not in line with the resolution on which coupling is to take place. If the application of Reference Day coincides the first day of the 15-minute MTU go-live, or with one of the first weekend delivery days, the results will be in 60-minute resolution.
This case is relevant for:
- First weekday, go-live (30 September 2025, DD 1 October 2025) -> Reference Day used DD 30th September
- First Saturday (3 October 2025, DD 4 October 2025) -> Reference Day used DD 27th September 2025
- First Sunday (4 October 2025, DD 5 October 2025) -> Reference Day used DD 28th September 2025
For any other day during a rollback period, the normal reference day applies.
The full 2025 Nordic Fallback calendar is available here: https://www.nordpoolgroup.com/4aa55e/globalassets/download-center/day-ahead/nordic-fallback-calendar.pdf
In the unlikely event of Rollback, for the first day back to 60-minute MTU the Reference Day is the previous weekday which is in 15-minute MTU resolution.
For further details, please refer to section 7.3 of the Day-Ahead Market Regulations for the Nordic/Baltic and CE Markets: https://www.nordpoolgroup.com/49f00c/globalassets/download-center/rules-and-regulations/day-ahead-market-regulations-september-2025.pdf