Preparation for the introduction of 15-min products in the Day-Ahead and Intraday Markets – Call for active participation in the on-going testing acti

The European energy market is undergoing a significant transformation with the planned implementation of a 15-minute Market Time Unit (MTU) in the Single Day-Ahead Coupling (SDAC) by June

1. More specifically, starting June 11, 2025 (for delivery date June 12, 2025) the Market Time Unit (MTU) in the Single Day-Ahead Coupling will move to a 15-minute resolution. At the same time, products with a 15-min and 30-min resolution will become available for trading in the continuous intraday market in the Greek bidding zone. Relevant public consultations on the adjustments needed in the regulatory framework, following the relevant proposals of the Hellenic Energy Exchange (HEnEx S.A.), the Independent Power Transmission Operator (IPTO S.A.), and the EnΕx Clearing House Single Member S.A. (EnExClear S.A.) have either been concluded or are on-going. The Authority plans to issue the relevant decisions within the month of May. In view of the above, we urge all Market Participants to participate actively in the testing activities currently conducted by HENEX and IPTO to confirm the compatibility of their internal systems with the new system functionalities. It will also ensure familiarity with the relevant procedures and any changes that may affect their operations. This is a valuable opportunity to validate critical processes such as order management, trade execution, results publication, and asset position monitoring. By thoroughly exploring these areas now, a smooth transition and minimization of any disruptions prior to the Go Live can be assured. RAAEY strongly encourages market participants to begin testing as soon as possible, as this will help identify any potential issues early on and facilitate a smooth transition. Please contact HEnEx and IPTO for further information. SDAC 15-min MTU Information Package Updated on 07/10/2025 Introduction The European energy market is undergoing a significant transformation with the planned implementation of a 15-minute Market Time Unit (MTU) in the Single Day-Ahead Coupling (SDAC) by June
2. This initiative aims to enhance market efficiency, better integrate renewable energy sources and improve grid stability across Europe. This paper provides an overview of the 15-minute MTU implementation in SDAC, its regulatory framework, anticipated benefits and the challenges associated with this transition. Regulatory Framework The move towards a 15-minute MTU is rooted in the European Union's legal framework, which mandates all Transmission System Operators (TSOs) in EU Member States to adopt a 15minute time resolution for imbalance settlement. The Agency for the Cooperation of Energy Regulators (ACER) ACER’s Algorithm Methodology dictates all Nominated Electricity Market Operators (NEMOs) to offer 15-minute products for trading on both Single Intraday Coupling (SIDC) and Single Day-ahead Coupling (SDAC) markets. The goal is to harmonize market operations across Europe, ensuring consistency and enhancing the efficiency of electricity balancing processes. ACER has also amended the relevant methodologies to facilitate this transition, emphasizing the need for improved algorithm performance to handle the increased data volume associated with 15-minute MTUs. Implementation Timeline The transition to a 15-minute MTU is scheduled for 11 June 2025, with the first delivery date on 12 June
3. This change will affect all bidding zones and borders within the SDAC. The implementation involves significant updates to the Euphemia algorithm, central to market coupling, to accommodate the new time resolution and ensure efficient cross-product matching. Anticipated Benefits The adoption of a 15-minute MTU is expected to yield several benefits: Enhanced Integration of Renewable Energy Sources: Shorter MTUs allow for more precise scheduling and dispatching of variable renewable energy, such as wind and solar, whose outputs fluctuate within shorter time frames. Improved Grid Stability: A finer time resolution aids in better forecasting and balancing of supply and demand, reducing imbalances and enhancing overall grid reliability. Increased Market Efficiency: Market participants can engage in more granular trading, optimizing their positions and responding more effectively to market signals. What is SDAC 15-Minute MTU? SDAC is the mechanism that integrates national day-ahead electricity markets across Europe into a single, efficient market. It enables electricity trading between different countries using a common algorithm, Euphemia, which determines optimal electricity flows and prices, based on supply and demand. Currently, the standard Market Time Unit (MTU) in the SDAC is one hour. The shift to a 15-minute MTU means trading and scheduling of electricity will occur in 15-minute intervals, instead of hourly. This shorter trading period allows for greater precision in balancing electricity supply and demand, especially as renewable energy sources, such as wind and solar, introduce more variability into the grid. With the 15-minute MTU, market participants will be able to place bids for buying or selling electricity in four separate 15-minute units within each hour. This will increase flexibility in the market and allow for better integration of intermittent renewable generation. Block orders can be defined from any quarter. How will the 15-Minute MTU Work? The transition to a 15-minute MTU involves several key elements: Market Participation and Trading: § § § All NEMOs will be required to offer 15-minute products for trading in the SDAC. Market participants can submit bids to buy or sell electricity for 15-minute periods. The Euphemia algorithm is upgraded to handle the increased number of bids and optimize price formation. Clearing and Price Calculation: § § The market coupling algorithm will match supply and demand at 15-minute intervals, ensuring the most efficient allocation of electricity across Europe. Prices will be calculated separately for each 15-minute period, reflecting realtime conditions more accurately. Cross-Border Trading: § § § The new MTU will apply across all bidding zones and borders within the SDAC. All shadow auctions currently organized by JAO as a back-up solution will remain in 60-minute resolution. The list of available shadow auctions can be found on the [JAO] website. Note that some TSOs can allow also nominations in 4 equal 15-minute MTU resolution. TSOs will coordinate the cross-border electricity flows based on the updated market clearing results. Integration with Balancing Markets: § § The 15-minute MTU aligns with European balancing market reforms, where imbalance settlements will also move to a 15-minute resolution. This synchronization ensures that deviations from forecasts are corrected more quickly, enhancing system reliability. Time Resolution of Products Offered by NEMOs When 15-min MTU Is Implemented in SDAC The following highlights can be observed on the map below: 15-min MTU is confirmed (except in Ireland); Most NEMOs will keep hourly products alive except: § § SEMO Px (derogation is granted, 15-min MTU will not be implemented in 2025 in Ireland) OMIE (ES, PT) 30-min Period Orders (POs) will be offered by some NEMOs on top of 15-min and 60min granularities. 15’ MTU and 60’ Period Orders (POs) 15’ MTU, 30’ and 60’ POs 15’ MTU 30’ POs NORDPOOL NORDPOOL EPEX SPOT EPEX SPOT NORDPOOL EPEX SPOT NORDPOOL NORDPOOL 1 NORDPOOL SEMO Px SEMO Px NORDPOOL TGE EPEX SPOT 1 NORDPOOL EPEX SPOT EXAA 2 1 1 OTE OKTE EPEX SPOT NORDPOOL NORDPOOL EPEX SPOT EXAA 2 HUPX OPCOM BSP CROPEX GME IBEX OMIE OMIE HEnEx 1 – NORDPOOL and EPEX SPOT 2 – EXAA proposed 15’MTU and 60’ POs The table below shows the BZs covered with their respective granularities. NEMOs Covered BZs 15' MTU 30' POs 60' POs BSP SI ✔ CROPEX HR ✔ ✔ ✔ EPEX SPOT NO, SE, FI, DK, PL, DELU,NL, BE, FR, AT ✔ ✔ ✔ EXAA AT, DE ✔ GME IT ✔ HEnEx GR ✔ ✔ HUPX HU ✔ ✔ IBEX BG ✔ ✔ NORDPOOL NO, SE, FI, DK, EE, LT, LV, PL, DE-LU, NL, BE, FR, AT ✔ OKTE SK ✔ OMIE ES, PT ✔ OPCOM RO ✔ OTE CZ ✔ SEMOPx IE, NI TGE PL ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ The main relevant documents can be found here: - Updated Euphemia public description [LINK] Products that can be taken into account in the Single Day-Ahead Coupling [LINK] Report on the outcome of the public consultation on SDAC Products methodology in view of SDAC 15min MTU [LINK] Alternatives to SDAC second auction [LINK] Q&As on SDAC second calculation [LINK] MCCG material on [ENTSO-E] and [NEMO Committee] websites Conclusion The implementation of 15-minute MTU in SDAC represents a pivotal step towards a more efficient and resilient European energy market. TSOs and NEMOs have worked hard in order to provide reliable infrastructure and robust processes to couple the European Energy Market. While the transition poses challenges and technical complexity, the collaborative efforts of regulatory bodies, TSOs, NEMOsand market participants are crucial to ensuring a smooth and successful adoption. This initiative not only aligns with the EU's objectives for renewable energy integration and market harmonization, but also sets the stage for a more dynamic and responsive energy system in the future.