Commitment to timely implementation of 15-minute Market Time Unit in Single Day-Ahead Coupling on 11th June 2025

Prague, Vienna, Oslo, Rome, Athens, Bratislava, Madrid, Sofia, Warsaw, Zagreb, Bucharest, 30th April, 2025

The NEMOs subscribing to this note affirm their full readiness and commitment to proceed with the scheduled go-live of the 15-minute Market Time Unit (MTU) in the Single Day-Ahead Coupling (SDAC) on 11 June 2025 as jointly agreed among all participating Transmission System Operators and NEMOs.

We want to make clear that we do not share the misgivings recently expressed in public by one NEMO concerning ‘project robustness’ without consultation with other Project Parties. NEMOs and TSOs have always been fully transparent with market participants, consistently updating them on the project's progress and providing all necessary information and will continue to do so.

Our collaborative efforts with stakeholders across the market have yielded positive results, ensuring that the necessary infrastructure and processes are in place to support a successful implementation of 15-minute MTU. The ‘problems’ perceived by the abovementioned NEMO are not recognized by the other project parties.

The transition to a 15-minute MTU is a pivotal advancement in enhancing the efficiency and flexibility of the European electricity market. It is instrumental in facilitating the integration of renewable energy sources and improving grid stability. Our extensive preparation and rigorous testing have demonstrated the robustness and reliability of our systems to handle the increased complexity associated with the 15-minute MTU.

Furthermore, it is worth reminding that overall readiness for go- live is measured against objective criteria agreed by NEMOs and TSOs.

Delaying the implementation could hinder progress towards a more integrated and responsive energy market. We believe that adhering to the original timeline is crucial for maintaining momentum in market development and delivering the anticipated benefits to all participants.

All undersigned NEMOs continue supporting the agreement for the go-live on 11 June 2025, and are working closely with all NEMOs, TSOs, Market Participants and regulatory authorities (EC, ACER, NRAs….) towards this goal. Following this explanatory note, we are confident that the mentioned concerns expressed by one NEMO have been addressed or can be addressed within the implementation project in the 
remaining time until go-live.

The next steps will be agreed and published by the Market Coupling Steering Committee.

Annex:

Remarks on the issues described in EPEX SPOT’s announcement:

• The SDAC Mechanism and Market Results Publication: The testing sessions that ended in full decoupling were not due to a lack of reliability in the relevant MCO systems and procedures supporting 15-minute products testing activities (15’ MTU). The testing sessions that ended in full decoupling were due to internal local/regional testing issues of certain parties in the initial stage of the testing phase. 
• The Central Matching Algorithm: Despite the significant challenge posed by the 15-minute MTU for MCO systems, all performance tests of the matching algorithm (Euphemia) have been successfully completed and validated by all parties, including EPEX SPOT. The results demonstrated the quality of the outcomes and the computational timings (i.e., "time to first solutions") met the criteria set in the master test plan.
• Unmet Quality Criteria: Majority of test scenarios, both functional and procedural, have been successfully completed and validated. The remaining open test scenarios are planned in the following days. Any reference to the IDAs scenario is misleading and inappropriate, as all IDAs decouplings were caused by local issues, and the time allocated to IDA execution is less than 25% of the overall time available for SDAC.

The pdf version of the communication note is available here.