The following five interconnectors were decoupled: IT-FR, IT-AT, SI-AT, SI-HR and IT-GR. On 13th January 2021, an incident took place in the day-ahead market coupling process that led to a partial decoupling of GME, BSP, EXAA, HEnEx and CROPEX, affecting the day-ahead trades with delivery day 14th January in the Multi-Regional Coupling (MRC).
More specifically, due to GME’s partial decoupling, also BSP, HEnEx, and EXAA markets were decoupled from the MRC process. The CROPEX market was run together with the market coupling session, but with no capacity with MRC markets, due to the impacted interconnector SI-HR, which is currently the only link to MRC.
The cause was an unexpected technical issue triggered by a hidden parameter of GME’s local trading system that prevented GME to create the order books. The problem was solved at around 13:00, when the partial decoupling had already been declared.
Following the partial decoupling of GME,BSP, EXAA, and HEnEx from MRC, shadow auctions for cross-zonal capacity were run for five interconnectors by JAO. Following the declaration of the partial decoupling by the Incident Committee, the shadow auction results were sent to market participants. For the impacted interconnectors, shadow auctions were triggered in line with the fallback procedures.
Local auctions were successfully completed shortly after 14:00 for the concerned local markets (GME,BSP, EXAA, and HEnEx).
Although this partial decoupling did not lead to any grid security issues anywhere in Europe, this incident caused a disruption of the day-ahead market within the Multi-Regional Coupling. More specifically, processes on market parties’ and TSOs’ side were impacted; Italy, Slovenia and Greece were decoupled from the MRC process. Croatia remained part of the MRC process, although without capacity to be allocated, meaning that it was decoupled from a market perspective.
The MRC procedures in place to manage a partial decoupling, have been properly applied and proved successful in retaining the coupling among the bidding zones not involved in the issue. The decoupling event did not affect 4M MC (4M Market Coupling), which is not yet coupled with MRC, and did not induce major impacts on market prices or security of operations in 4M MC.
Due the growing number of coupled parties, the very large number of involved systems and the increasing complexity of operations, the possibility of incidents increases. Procedures were followed in the correct way bringing to the expected outcome the process in case of such negative situation.
