Extension of Single Day-Ahead Coupling (SDAC) to Bulgaria

The Bulgarian day-ahead market is now integrated via the Greek border in the Pan-European day-ahead power market

The market coupling operations of the Bulgarian bidding zone in SDAC (Multi Regional Coupling) were successfully launched today, the 11th of May 2021 with the first delivery day 12th of May 2021. IBEX, the designated single NEMO in Bulgaria is now included in the market coupling operational processes, along with ESO, the Bulgarian TSO. The successful coupling is the result of the close collaboration between the Bulgarian parties with HEnEx, the designated Greek NEMO and IPTO, the Greek TSO, together with the respective NRAs.

The Bulgarian – Greek market coupling project was launched as a part of the Italian Borders Working Table (IBWT) regional project with the official IBWT SC decision taken on the 1st of March 2020. All the involved parties followed the mutually agreed planning and completed timely and successfully all necessary preparations and testing.

Today, for the first time, day-ahead cross-zonal capacity between Greece and Bulgaria has been implicitly allocated via the Euphemia algorithm. The implemented price coupling allows for the simultaneous calculation of electricity prices and cross-border flows across the region. The efficient use of the power system and cross-border infrastructures, brought about by stronger coordination between energy markets, maximizes social welfare to the benefit of all market participants.

The integration of the Bulgarian bidding zone into SDAC is a further step towards the achievement of the European target model, which is expected to be almost completed this year through the Bulgarian – Romanian market coupling project on the common border and as a previous step, the successful implementation of the Interim Coupling project, allowing the integration of the 4M MC with MRC through their common borders.

About SDAC

SDAC allocates scarce cross-border transmission capacity in the most efficient way by coupling wholesale electricity markets from different regions through a common algorithm, simultaneously taking into account cross-border transmission constraints, thereby maximising social welfare.

The aim of SDAC is to create a single pan European cross zonal day-ahead electricity market. An integrated day-ahead market increases the overall efficiency of trading by promoting effective competition, increasing liquidity and enabling a more efficient utilisation of generation resources across Europe.

For additional information on SDAC go to: