During the market coupling process on 28 October a technical issue was experienced that led to a partial decoupling.

• Country/Bidding zone decoupled from a market point of view from SDAC: Greece
• Order book decoupled from the SDAC process: HEnEx
• Interconnectors decoupled from the SDAC process: GR-BG, GR-IT

The incident was caused by a technical issue at HEnEx Local Trading System. HEnEx reported that experienced a severe technical issue at its Local Trading System impending the validation process of submitted orders in DAM relevant to the day-light saving time additional MTU for delivery day 29/10/2023. The issue could not be fixed within the time allocated by the SDAC procedures and partial decoupling was declared. The final market coupling results for the remaining coupled parties were published at 14:05 CET. The common coupling system worked as expected and ensured the coupling of the remaining part of SDAC.

The MCSC has initiated an in-depth investigation. A decoupling report summarising the outcome of the investigation and potential lessons learned is expected to be published within a month time.