Single Intraday Coupling (SIDC)

What is Single Intraday Coupling (SIDC)?

Single Intraday Coupling (SIDC) creates a single EU cross-zonal intraday electricity market. In simple terms, buyers and sellers of energy (market participants) are able to work together across Europe to trade electricity continuously on the day the energy is needed.

An integrated intraday market makes intraday trading more efficient across Europe by:

  • promoting competition

  • increasing liquidity

  • making it easier to share energy generation resources

  • making it easier for market participants to allow for unexpected changes in consumption and outages

As renewable intermittent production such as solar energy increases, market participants are becoming more interested in trading in the intraday markets. This is because it has become more challenging for market participants to be in balance (i.e. supplying the correct amount of energy) after the closing of the day-ahead market.

Being able to balance their positions until one hour before delivery time is beneficial for market participants and for the power systems alike by, among other things, reducing the need for reserves and associated costs while allowing enough time for carrying out system operation processes for ensuring system security.

How Single Intraday Coupling began

Single Intraday Coupling (SIDC) is an initiative between Nominated Electricity Market Operators (NEMOs) and Transmission System Operators (TSOs) which enables continuous cross-border trading across Europe.

SIDC follows on from the XBID (Cross Border Intraday) project which delivered, in June 2018, the first go-live of the intraday continuous trading platform. It allows energy networks to integrate and expand across Europe.

The SIDC was launched on 12/13 June 2018 across 14 countries. In the first 16 months of operation over 25 million trades were completed across the countries involved. On 19/20 November 2019 SIDC went live across a further seven countries resulting in 22 countries being coupled.

SIDC is in line with the CACM (Capacity Allocation and Congestion Management) EU Target model for an integrated intraday market.

SIDC geographical scope and future go-live phases

SIDC will expand in several phases, also referred to as waves. The map below shows the geographic spread of the first and second waves which have been implemented. A third wave is planned and the scope may expand beyond that shown.

The first go-live wave was in June 2018 and included 15 countries. A second go-live with seven further countries was achieved in November 2019. A third wave including Italy is foreseen for Quarter 3 of 2021. The table below lists the countries of the first and second waves.

First Go-Live in June 2018Second Go-Live in November 2019
15 countries7 countries
The Netherlands 

To accomplish SIDC, TSOs and NEMOs work in close collaboration.

The organisations involved are:

Transmission System Operators (TSOs):


Nominated Electricity Market Operators (NEMOs):


Governance structure

The governance of the SIDC consists of three layers which are governed by separate agreements.

  1. Joint NEMOs and TSOs: governed by the Intraday Operation Agreement (IDOA)

  2. Only NEMOs: governed by the ALL NEMO-Intraday Operation Agreement (ANIDOA)

  3. Only TSOs: governed by the Transmission Cooperation Agreement (TCID)

In each case, the governance structure follows a similar approach with:

  • a steering committee at the top,

  • support groups (SG) and task forces (TF),

  • three joint groups dealing with operations:

    • Operations Subcommittee (OPSCOM) and Change Control,

    • Quality Assurance and Release Management (QARM), and

    • Market and System Design (MSD)

Joint NEMOs and TSOs governance structure

How Single Intraday Coupling works

SIDC works on a common IT system with:

  1. a Shared Order Book (SOB),

  2. a Capacity Management Module (CMM), and

  3. a Shipping Module (SM).

This means that orders entered by market participants for continuous matching in one country can be matched by orders submitted by market participants in any other country as long as they are both within the project’s reach and transmission capacity is available.

The intraday solution supports continuous trading that is both:

  • explicit (capacity only. Note: only provided where requested by National Regulatory Authorities (NRAs) ie. at the French-German and the Croatian-Slovenian borders), and

  • implicit (capacity and energy together)

When market participants of each NEMO submit orders, they are put together in one Shared Order Book (SOB). In a similar way, TSOs make available all the intraday cross-border capacities in the Capacity Management Module (CMM).

This allows NEMOs to operate trading systems to show orders to market participants from other market participants in three groups:

  1. within the same NEMO

  2. from other NEMOs in the same market area

  3. from other market areas as long as there is enough capacity available

How Single Intraday Coupling works in detail

When a market participant submits an order for a different market area, it can be matched (i.e. met) as long as there is enough capacity available. To match an order simply means that the market participant can meet and supply the energy demand.

Trade is done on a first-come first-served principle where the highest buy price and the lowest sell price get served first.

Updating the SOB and CMM

When the order can be matched, the order matching is associated with implicit capacity allocation (this is when capacity and energy are priced together). While two orders are being matched, the SOB and CMM are updated immediately.

The update of the SOB means that the matched orders are removed from the SOB, and consequently the available transmission capacity in the CMM is updated. The number of borders that have their capacities updated depends on where the matched orders are located.

How data about trades is used

The Shipping Module (SM) receives data from the SOB about all trades when they are concluded. These can be:

  • between two different delivery areas, and

  • in the same delivery area between two different NEMOs.

The Shipping Module (SM) of the SIDC solution provides information from concluded trades to all relevant parties such as NEMOs and TSOs.

The data from the SOB and the CMM is enhanced with data from:

  • the relevant TSO,

  • the Central Counter Party (CCP), and

  • shipping agent data from the Shipping Module (SM).

This enhanced data is then sent to relevant parties such as the NEMOs and TSOs at the configured moments.

Market information

Products available

You can read what specific products are available in different market areas in the table below.

30-min products are currently tradable across the borders FR-DE, FR-BE and BE-NL.

15-min products are currently tradable across the borders BE-NL, BE-DE, NL-DE, AT-DE, AT-HU, AT-SI and HU-RO.

The availability of 15 minute products across other market areas will further expand in the future.

Number of trades per quarter

From mid-June to 2018 to the end 2020, more than 71 million trades have occurred through SIDC.

Go-Live periodNumber of trades
Mid-June to September 20183.5 million
October to December 20184.3 million
January to March 20194.8 million
April to June 20195.8 million
July to September 20195.6 million
October to December 20197.2 million
January to March 20208.3 million
April to June 20209.3 million
July to September 202010.8 million
October to December 202011.9 million

Future development

The development of SIDC is important to all parties (NEMOs and TSO) involved in the project.

Here we list future developments to expand and improve the efficiency of the SIDC.

  1. Plans are underway to integrate cross-zonal capacity pricing through intraday auction in line with ACER’s decision on establishing a single methodology for pricing intraday cross-zonal capacity.

  2. SIDC is working on the implementation of cross-product matching into the system. This will enable the matching of different products with one another (for example 15 min with 60 min orders).

  3. A new release of SIDC (Release 3.1) is expected to be deployed in Q2 2021. This will add upgrades to fulfil regulatory obligations as regards the publication of operational data as well as improving operational usability of the system.

  4. Plans are underway to implement the functionality to address losses on HVDC cables.

  5. SIDC has recently initiated the R&D phase for the implementation of flow-based allocation in continuous trading.

Resources Available

Steering Committee Minutes

Market Involvement

A User Group was convened with Market Parties (MPs) as an interface between the XBID Project and the Market. Following the successful XBID Go-Live it is agreed that the Market European Stakeholder Group (MESC) is the primary interface with MPs.

1st User Group Meeting

2nd User Group Meeting

3rd User Group Meeting

4th User Group Meeting

5th User Group Meeting

6th User Group Meeting

7th User Group Meeting

8th User Group Meeting

9th User Group Meeting

1st Go-Live Pre-Launch Event Presentations

2nd Wave Pre-Launch Event Presentations

XBID Information Package

Press Releases:

2021 03 25 - Revised Local Implementation Project 14 Go-Live

2020 11 20 - Expansion of 30 and 15 minute products and Revised Local Implementation Project 14 Go-Live

2020-04-08 - NEMOs and TSOs are safeguarding the Day-Ahead and Intraday market coupling

2019-11-08 - Date confirmation of the 2nd wave go-live

2019-06-12 - XBID – 1st anniversary and announcement of 2nd Wave Go-Live

2019-04-02 - 2nd go live impact

2018-12-05 - 2nd Wave and Gate Opening Time

2018-09-06 – Successful Go-Live and End of Rollback