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:
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.
Learn more about the single intraday coupling (SIDC)
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.
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 will expand in several phases, also referred to as “waves”. The map below shows the geographic spread of the first, second and third waves which have been implemented. Further waves are 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 go-live including Italy in September 2021. The table below lists the countries of the first, second and third waves.
First Go-Live in June 2018
Second Go-Live in November 2019
Third Go-Live in September 2021
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 and TGE.
The governance of the SIDC consists of three layers which are governed by separate agreements.
Joint NEMOs and TSOs: governed by the Intraday Operation Agreement (IDOA)
Only NEMOs: governed by the ALL NEMO-Intraday Operation Agreement (ANIDOA)
Only TSOs: governed by the Transmission Cooperation Agreement (TCID)
In each case, the governance structure follows a similar approach with:
Joint NEMOs and TSOs governance structure
In all cases, the governance structure follows a similar approach with a Steering Committee on top, some horizontal groups and three joint groups dealing with operations: Market & System Design, Quality Assurance & Release Management and OPSCOM.
Joint NEMOs and TSOs governance structure
SIDC works on a common IT system with:
a Shared Order Book (SOB),
a Capacity Management Module (CMM), and
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:
within the same NEMO
from other NEMOs in the same market area
from other market areas as long as there is enough capacity available
Learn more about 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.
The Shipping Module (SM) receives data from the SOB about all trades when they are concluded. These can be:
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:
This enhanced data is then sent to relevant parties such as the NEMOs and TSOs at the configured moments.
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 end of Q3 2021,114 million trades have occurred through SIDC.
Number of trades
Mid-June to September 2018
October to December 2018
January to March 2019
April to June 2019
July to September 2019
October to December 2019
January to March 2020
April to June 2020
July to September 2020
October to December 2020
January to March 2021
April to June 2021
July to September 2021
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.
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.
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.
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.
SIDC is working on the implementation of cross-product matching. This will enable the matching of different products with one another (for example 15 min with 60 min orders).
SIDC is currently closely working together with SDAC to establish a joint governance between the projects. This initiative aims at delivering a joint decision-making body, which will be responsible for both projects, as well as the merger of the legal and communication working groups. The go-live of the joint governance setup is planned in Q1 2022
Plans are underway to implement the functionality to address losses on HVDC cables.
SIDC has initiated the R&D phase for the implementation of flow-based allocation in continuous trading
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:
a. operational contracts;
b. operational procedures;
c. change control procedures
d. monitoring procedures;
e. fallback procedures; and
f. 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.
SIDC Joint Documentation
Intraday Operational Agreement (IDOA)
Exhibit 6 – Operational procedures – see separate list below
Exhibit 17: Includes XBID_JOINT_NOR_03 and XBID_JOINT_NOR_04 included also below under the procedures overview
6_Exhibit 6 – Joint XBID Procedures
XBID_JOINT_CFG_01 SM Configuration
SIDC TSO only documentation
TSO Cooperation Agreement for Single Intraday coupling (TCID)
APPENDIX D - TSO-only operational procedures
APPENDIX D - TSO operational procedures
SIDC NEMO Only Documentation
ANIDOA Initial version
ANIDOA Annex 07 – Operational procedures – see separate below
ANIDOA Annex 07 – Operational procedures
ANIDOA First Amendment