Intraday Auctions

On the basis of Decision 01/2019 on the Methodology for pricing intraday cross-zonal capacity by the Agency for the Cooperation of Energy Regulators (ACER), intraday auctions are being implemented within the single electricity market in the EU.

The intraday auction (IDA) refers to an implicit intraday auction carried out within the single (intraday) European electricity market for the purpose of allocating available intraday transmission capacity using a market-coupling mechanism between individual bidding zones. It represents a trading platform for intraday auction trading that complements the existing intraday market.

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.

The entities involved in the intraday auctions include Nominated Electricity Market Operators (NEMOs) and Transmission System Operators (TSOs) who use XBID (Cross-border Intraday Coupling) technical solutions, PMB system (PCR Matcher and Broker) and Euphemia algorithm, new IDA CIP interface (Intraday Auction Central Interface Point) creating a connection between the auction algorithm and intraday trading algorithm, shipping systems and other regional systems.

The message formats used for intraday auctions are part of the documentation for the transition to the 15min deviation counting period - can be found here. (CZECH ONLY)

Organization of intraday auctions

For the respective delivery day (hereinafter „D“), 3 intraday auctions will be held in the following time sequence:

• IDA1: D-1 15:00 for all D delivery hours
• IDA2: D-1 22:00 for all D delivery hours
• IDA3: D 10:00 for delivery hours 12:00-24:00 on D

A more detailed time schedule is shown in the following figure.

Figure 1 - Time chart of intraday auctions

Since the solution for the intraday auctions is based on the day-ahead market platform, the intraday auction includes similar processes as the day-ahead market only in shortened time intervals. Each intraday auction will consist of 3 phases:

1. Collection and submission of input data for IDA, the Pre-coupling
2. The IDA calculation process up to the moment of validation of the results, the Coupling

• Submission and processing of IDA results and output data, the Post-coupling

Pre-coupling will take 20 minutes before the gate closure time, and coupling and post-coupling will cover 20 (in exceptional cases up to 30) minutes after the gate closure time. Within the intraday auctions, neither the full decoupling of markets nor a second auction will be supported to speed-up the process.

Implications for continuous trading

During the time when individual intraday auctions are organized (for VDA1 at 2:40 p.m. – 3:30 p.m., for VDA2 at 9:40 p.m. – 10:40 p.m. and for VDA3 at 9:40 a.m. – 10:40 a.m.), the possibility to trade on the continuous intraday market will be maintained but taking into account that capacity allocation on the continuous intraday market will not be possible. During this time, trading on the continuous intraday electricity market will be possible only within the given delivery area (the Czech Republic).

Traded products

The launch of the intraday auctions is expected in 06/2024, with only 60 min products. As of July 1, 2024, there will be a transition to a 15-minute settlement period in the Czech Republic, and it will be possible via the intraday auctions to trade products with 15-minute granularity only. (More information on the transition to the 15-minute settlement period here.) The specific products offered will be specified based on performance tests (at least regular orders and simple block orders will be offered).

In Q1 2024, European transmission system operators and nominated electricity market operators plan to provide more information on the intraday auction process and the technical impacts on market participants. Testing with market participants is expected at the end of Q1/2024 or at the beginning of Q2/2024.

Presentation from the webinar held on March 7, 2024 - Details on the changes in short-term electricity markets in 2024/25 due to the implementation of a 15-minute trading period in the Czech Republic, intraday auctions, and a 15-minute settlement discrepancy.