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:
increasing liquidity (i.e. increasing the ease with which energy can quickly be bought and sold without affecting its price)
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 balanced on the network closer to 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.
How Single Intraday Coupling began
Single intraday coupling (SIDC) is an initiative between the 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 have been completed across these countries. On 19/20 November 2019 SIDC went live across a further seven countries resulting in 21 countries being coupled.
How SIDC works
It 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 (supply meeting demand) in one country can be matched by orders submitted by market participants in any other country. They can be matched as long as they are 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 NRAs), and
implicit (capacity and energy together)
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 phases, or waves. The map below shows the geographic spread of the first and second wave 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 14 countries. A second Go-Live with seven further countries was achieved in November
- A third wave including Italy and Greece is foreseen for Quarter 4 of 2020. The table below lists the countries of the first and second waves.
|First Go-Live in June 2018||Second Go-Live in November 2019|
|14 countries||7 countries|
To accomplish the SIDC, TSOs and NEMOs work in close collaboration.
The organisations involved are:
Transmission System Operators (TSOs):
50HERTZ, ADMIE, AMPRION, APG, AST, BritNed, ČEPS, CREOS, EirGrid, ELERING, ELES, ELIA, ELSO, ESO, FINGRID, HOPS, Litgrid, MAVIR, NGIC, PSE, REE, REN, RTE, SONI, STATNETT, SVENSKA KRAFTNÄT, TenneT DE, TenneT NL, TERNA, TRANSELECTRICA and TransnetBW.
Nominated Electricity Market Operators (NEMOs):
BSP, CROPEX, EirGrid, EPEX, EXAA, GME, HEnEx, HUPX, IBEX, Nord Pool EMCO, 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:
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
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
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.
For borders where NRAs (National Regulatory Authorities) requested, explicit allocation is made available to explicit participants. Currently this is only at the French-German border.
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.
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 expand in the future.
Number of trades per quarter
From mid-June to 2018 to end October 2019, over 26 million trades have occurred through SIDC.
|Go-Live period||Number of trades|
|Mid-June to September 2018||3.5 million|
|October to December 2018||4.3 million|
|January to March 2019||4.8 million|
|April to June 2019||5.8 million|
|July to September 2019||5.6 million|
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.
- A new release of SIDC (Release 2.0) was deployed at the end of October 2019. This added upgrades to:
integrate additional non-Multi NEMO areas into the intraday coupling, and
increase the depth of the Shared Order Book (SOB) from 31 to 100.
Plans are underway to implement functionality to address losses on HVDC cables.
Plans are underway to integrate cross-zonal capacity pricing through auction needs in line with ACER’s decision on establishing a single methodology for pricing intraday cross-zonal capacity.
In the longer-term, flow-based allocation and non-standard intraday products are two areas that need to be addressed.
Steering Committee Minutes
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.