European cross-border Single Intraday Coupling (SIDC) was introduced in June 2018 (then called XBID) to increase the overall efficiency of intraday trading through effective competition, increased liquidity, and more efficient use of generation resources. The overarching objective is the integration of the European energy market. In November 2019, SIDC was extended in a second go-live, so that currently the markets of 22 countries are coupled through SIDC: Austria, Belgium, Denmark, Estonia, Finland, France, Germany, Latvia, Lithuania, Luxembourg, Norway, the Netherlands, Portugal, Spain, Sweden (first go-live), and Bulgaria, Croatia, the Czech Republic, Hungary, Poland, Romania, and Slovenia (second go-live).
The Nominated Electricity Market Operators (NEMOs) from the seven countries of the second go-live report significant growth in trading volume in the coupled intraday market. The Hungarian NEMO HUPX, for example, recorded an average monthly trading volume of around 75,600MWh from December 2019 to February 2020 compared to 7,600MWh in the same period of the preceding year; in the Czech Republic, the volume has increased eightfold. The other NEMOs are also registering significant growth rates. A total of 36 million trades have been executed since SIDC first went live, and the system continues to operate reliably after the second wave.
The SIDC solution is based on a common IT system with a shared order book, a capacity management module and a shipping module. The TSOs cooperating in SIDC include the TSCNET shareholders 50Hertz, Amprion, APG, ČEPS, ELES, HOPS, MAVIR, PSE, TenneT, Transelectrica and TransnetBW, as well as the TSCNET customer Creos from Luxembourg and Energinet from Denmark. With the accession of the NEMO OKTE and further TSCNET shareholder SEPS, the TSO from Bratislava, the project has meanwhile been extended to Slovakia. A third go-live to expand continuous cross-border intraday trading to Greece and Italy is expected in the first quarter of 2021.