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 via market coupling and to expand trading possibilities across Europe.

SIDC was launched on 12/13 June 2018 across 15 countries. In November 2019 SIDC went live in seven further countries and in September 2021 one additional country joined, resulting in 23 countries being coupled. In November 2022 the fourth go-live wave was achieved with 2 more countries. In total, as of today, 25 countries are coupled.

The table below lists the countries of the first, second, third, and fourth waves. SIDC is in line with the CACM (Capacity Allocation and Congestion Management) EU Target model for an integrated intraday market.

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

Involved Parties

Transmission System Operators (TSOs):

50Hertz Transmission, ADMIE, Amprion, APG, AST, ČEPS, Creos, EirGrid, Elering, ELES, ELIA, ELSO, Energinet, 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.

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 set-up allows NEMOs to operate their trading systems showing to market participants orders:

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

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 concluded 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 Is Data About Trades 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.

Continuous trading matching algorithm public description

Available products by market are listed in the table below.

15-min Products

30-min Products