Single Intraday Coupling (SIDC)

What is Single Intraday Coupling?

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 a cooperation 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.

SIDC was launched on 12/13 June 2018 across 15 countries. In the first 16 months of operation over 25 million trades were completed across the countries involved. In November 2019 and September 2021, SIDC went live across a further eight countries resulting in 23 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, second, third, and fourth waves which have been implemented.

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 go-live including Italy in September 2021. In November 2022 the fourth go-live was achieved with Greece and Slovakia. The table below lists the countries of the first, second,third, and fourth waves.

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

The organisations involved are:

Transmission System Operators (TSOs):

50HERTZ, ADMIE, AMPRION, APG, AST, ČEPS, CREOS, EirGrid, ELERING, ELES, ELIA, ELSO, ESO, FINGRID, HOPS, Litgrid, MAVIR, PSE, REE, REN, RTE, SEPS, SONI, STATNETT, SVENSKA KRAFTNÄT, TenneT DE, TenneT NL, TERNA, TRANSELECTRICA and TransnetBW.

Nominated Electricity Market Operators (NEMOs):

BSP, CROPEX, EirGrid, EPEX SPOT, GME, HEnEx, HUPX, IBEX, Nord Pool, OKTE, OMIE, OPCOM, OTE, SONI, TGE, ETPA and BRM.

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 transmission 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.

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

Stakeholder reports

To give stakeholders a comprehensive overview of the benefits SIDC delivers, the project has prepared reports featuring several indicators including amongst others traded volumes, average prices, cross-border capacity utilisation, share of cross-bidding zone trades in overall volumes and availability of the SIDC platform. These reports cover the operational period since beginning of January 2019.

2023   Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov

2022   Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov - Dec

2021   Apr - May - Jun - Jul - Aug - Sep - Oct - Nov - Dec

2020   Q1/Q2 report - Q3/Q4 report

2019   Q1/Q2 report - Q3/Q4 report

Overview of Allocation Constraints in SIDC

Number of trades per quarter (in millions)

From mid-June 2018 to end of Q1 2022 151 million trades have occurred through SIDC.

SIDC has developed algorithm monitoring reports, which will be generated on a monthly basis. These reports contain among others key indicators on the performance of the algorithm, prices, matched orders and volumes and the usage of SIDC products.

Algorithm monitoring

Pursuant to Article 8 of Annex I of ACER decision 04/2020 on the Algorithm methodology, SIDC has developed algorithm monitoring reports, which will be generated on a monthly basis. These reports contain amongst others key indicators on the performance of the algorithm, prices, matched orders and volumes and the usage of SIDC products.

2023   Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov

2022   Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov - Dec

2021   May - Jun - Jul - Aug - Sep - Oct - Nov - Dec

Future development

The development of SIDC is a priority 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. Plans are underway to implement the functionality to address losses on HVDC cables.

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

Resources Available

• 19th MESC Slides
• 18th MESC Slides
• Q&A
• Florence Forum Slides

Steering Committee Minutes

• February 2022 MCSC Joint Steering Committee meeting 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.

• IDA pre launch event
  • Agenda
  • Information package
  • Presentation
  • Minutes IDA pre-launch event
• 4th Wave Go-Live Single Intraday Coupling (SIDC) Pre-launch Event
  • Presentation
  • Recording Morning session
  • Recording Afternoon session
• 3rd Wave Pre-Launch Event Presentations
• 2nd Wave Pre-Launch Event Presentations
• 1st Go-Live Pre-Launch Event Presentations

Press Releases

• 22 March 2024 - The SIDC held a pre-launch event about the new Intraday Auctions
• 1 February 2024 - SIDC invitation to the IDA go-live on Single Intraday Coupling (SIDC) Pre-launch Event
• 12 Jan 2024 - SIDC announces the successful launch of 15-minute MTU capacity allocation on HR-SI and HR-HU borders
• 28 Nov 2023 - Successful test of 15-minute MTU allocation on HR-SI and HR-HU borders
• 2 Aug 2023 - Successful go-live for ETPA as the third NEMO to operate in the Dutch Market Area within SIDC
• 28 Jul 2023 - Confirmation of Go-Live date for ETPA
• 15 Jun 2023 - Unsuccessful go-live for ETPA
• 12 Jun 2023 - Confirmation of Go-Live date for ETPA as the third NEMO to operate in the Dutch Market Area within SIDC
• 30 Nov 2022 - Successful fourth wave go-live
• 30 Sep 2022 - Expansion of 15-minute products to Bulgaria
• 5 Oct 2021 - Successful Local Implementation Project 14 Go-Live
• 14 Sep 2021 - Local Implementation Project 14 Go-Live confirmation
• 25 Mar 2021 - Revised Local Implementation Project 14 Go-Live

Information notes

• 18 Aug 2022 SIDC report on Critical Incident Experienced on 25th of July 2022

Intraday Operational Agreement

Publication of Intraday Operational Agreements according to article 20.7 of the Algorithm Methodology

According to article 20.7 of the Algorithm Methodology as approved by ACER all NEMOs shall in coordination with TSOs publish, by 1 September 2020, and then continuously update the relevant parts of the following documents:

1. Operational contracts
2. Operational procedures
3. Change control procedures
4. Monitoring procedures
5. Fallback procedures
6. Back-up procedures

Based on this regulatory requirement SIDC parties publish these documents for transparency purposes. Any consultation or use of these documents is at your own risk and responsibility and the parties to the SIDC cooperation cannot be held liable for any damage incurred as a result of the use of these documents. Furthermore, these documents can only be used or quoted provided prior written consent is obtained of the parties to the SIDC cooperation. No rights or obligations can be derived from these documents. The publication of these documents does not affect any (intellectual) property right pertaining to these documents or to the information contained therein. The publication of these documents does not preclude the rights of the parties to the SIDC cooperation to amend, replace or suppress the documents.

Please note the following:

1. For reasons of confidentiality certain parts of the content of the documents have been blackened out or have not been published (e.g. Exhibit 2, 13, 15 of the IDOA).

2. Exhibit 3 (Change Control Procedure), Exhibit 18 (OTH07-Algorithm monitoring procedure) and the related definitions in Exhibit 1 (Definition List) of the IDOA are to be adapted to reflect the relevant provisions of the Algorithm Methodology. For transparency reasons these documents are published subject to the reservation that they are still to be formally adopted by the parties to the SIDC cooperation via the signature of the Second IDOA Amendment.

Please note that for reasons of confidentiality certain parts of the content of the documents have been blackened out or have not been published (e.g. Exhibit 2, 13, 15 of the IDOA).