Intraday Auctions on SIDC

The Goal of IDAs

Pricing the intraday capacity - via Intraday Auctions (IDAs) - is part of the Single Intraday Coupling (SIDC) and it completes the SIDC market which was before solely based on the continuous trading method. IDAs were implemented across Europe on 13 June 2024, to allow for the pricing of cross-border capacity in the intraday timeframe.

The purpose of introducing the intraday auctions is to harmonize the calculation and allocation of cross-border capacities on the intraday market and to price intraday cross-border capacities to reflect their shortage at a given time and thereby send an adequate price signal to the market.

Intraday auctions provide the ability to accumulate offers and efficiently allocate the scarce transmission capacity. This is a novelty in the intraday timeframe, since capacity in the continuous intraday trading is allocated on a first-come first served basis. IDAs are the first intraday auctions involving most of the European countries.

IDAs were introduced in Austria, Belgium, Bulgaria, Czechia, Croatia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Luxemburg, The Netherlands, Norway, Poland, Portugal, Romania (the borders are not yet included), Slovakia, Slovenia, Spain, and Sweden.

The IDA Solution

IDAs are organized as implicit auctions where collected orders are matched, and cross-zonal capacity is allocated simultaneously for different bidding zone borders. IDAs take into account all valid orders submitted for the respective auctions and determine clearing prices for the relevant bidding zones based on matched orders.

Cross-zonal capacities cannot be allocated simultaneously for IDAs and for continuous trading along the same borders. Therefore cross-zonal capacity allocation within the continuous SIDC is suspended for a limited period during which the cross-zonal capacities are allocated via IDAs. Continuous intrazonal trading can only continue during the IDAs in those bidding zone where more than one NEMO is active.

High-Level Architecture

• XBID is used as source of network constraints data for IDA (pre-coupling) and to validate the IDA results in terms of capacity meeting the network constraints (coupling).
• Network data are provided via NEMOs to EUPHEMIA (auction algorithm).
• IDA results are submitted to XBID to update the information about Already Allocated Capacity (AAC) in XBID and to reflect in relevant CMM files the existence of capacity reserved for IDA results.
• IDAs Trading Solution is the same solution as used for day-ahead being adapted for IDAs, depending on each NEMO.
• IDA CIP is an intermediate system (interface) between XBID and NEMO Systems.

Resources Available

• 2025   IDA weekly reports
• 2024   IDA weekly reports

Information Notes