Slovenská elektrizačná prenosová sústava, a. s. (SEPS) in compliance with the company’s mission and vision takes an active part in activities influencing the pan‑European and Central-European electricity market. The cooperation of the European transmission system operators (TSOs) is implemented both via institutionalized entities such as ENTSO-E, JAO S.A., TSCNET Services GmbH and others and via implementation projects related to Network Codes and Guidelines. SEPS, a responsible TSO with long-standing experience, prefers efficiency, long-term sustainability and social responsibility in compliance with the applicable legal regulations.


ENTSO-E  (European Network of Transmission System Operators for Electricity) is an international association based in Brussels founded by Transmission System Operators (TSOs) in December 2008 in accordance with Regulation (EC) No. 714/2009 on conditions for access to the network for cross-border exchanges of electricity. ENTSO‑E currently unites 40 TSOs from 36 European countries. SEPS as a founding member of the ENTSO–E takes an active part in the activities of the working and steering structures of ENTSO-E via its appointed representatives.

The main tasks of ENTSO-E, derived from its legal mandates, are in particular:

  • Development and implementation of standards, Network Codes, platforms, and tools to ensure secure system and market operation, as well as integration of renewable energy sources to the system,
  • Assessment of the system adequacy in different timeframes,
  • Coordination of the planning and development of infrastructure at the European level (Ten-Year Network Development Plans, TYNDPs),
  • Coordination of research, development and innovation activities of TSOs,
  • Development of platforms to enable the transparent data sharing with market participants.

TSCNET Services GmbH

TSCNET Services GmbH, the company based in Munich renders its services for Transmission System Operators (TSOs) and their control centres to maintain the operational security of electricity system – 24 hours a day, seven days a week. TSCNET is one of the six Regional Coordination Centres (RCCs) and in accordance with Regulation (EU) 2019/943 on the internal market for electricity renders in a role of designated RCC as of July 1, 2022 following services:

  • Coordinated Security Analysis
  • Coordinated Capacity Calculation
  • Outage Planning Coordination
  • Short- and Medium-Term Adequacy Forecast
  • Common Grid Model
  • Emergency and Restoration Coordination Support
  • Critical Grid Situations Support

as well as development and consequently rendering new services arising from above mentioned Regulation.

The TSCNET’s shareholders and main customers are 16 TSOs from Europe. SEPS became the TSCNET shareholder in June 2018.


JAO (Joint Allocation Office) is a service company based in Luxembourg that on behalf of TSOs carries out:

  • yearly, monthly and daily auctions of electricity transmission rights on all internal EU borders,
  • shadow auctions which serve as back-up for Single Day Ahead Coupling,
  • clearing, settlement, contracting,
  • reporting, project support and IT services.

JAO became the Single Allocation Platform (SAP) in October 2018. The JAO´s shareholders are 25 TSOs from Europe. SEPS is the founding shareholder of CAO since 2008 (where CAO was JAO predecessor established by merge of CAO and CASC.EU in 2015).



CORE CCR (Capacity Calculation Region, CCR) represents region for capacity calculation that consist of 16 European TSOs and geographically covers significant part of Europe. CORE CCR was established in accordance with ACER Decision No. 16/02016 of November 2016. Within the CORE CCR are developed the procedures and methodologies related to optimization of the transmission capacity, cross-border trading and operation of interconnected transmission networks whilst maintaining high level of security of supply, as required by Network Codes and Guidelines. There is an ongoing process of developing and implementing following methodologies:

  • day-ahead flow-based capacity calculation for long term, day and intra-day time frames,
  • coordinated redispatching and countertrading to effectively relieve congestions within the interconnected transmission network.


The CORE Flow-based Market Coupling project represents an important step towards creating single electricity market in accordance with Regulation (EU) 2015/1222 establishing a guideline on capacity allocation and congestion management.

The Flow-Based approach represents a capacity calculation method in which the physical limits of the network are based on available margins on critical network elements (branches) and power transfer distribution factors which are defined for every critical branch and every bidding zone within the CORE CCR.

Project CORE FB MC went successfully live in June 2022.


The aim of Single Day-Ahead Coupling (SDAC) is to create a single pan European cross zonal day-ahead electricity market that increases the overall efficiency of trading and liquidity and enables more efficient utilization of generation resources.

SDAC allocates scarce cross-border transmission capacity in the most efficient way – through common algorithm, simultaneously considering cross-border transmission constraints and thereby maximizing social welfare. SDAC enables cross-border trading via implicit auctions for the delivery of power for the following day.


Single IntraDay Coupling (SIDC) represents a single European cross-zonal intraday electricity market. Market participants are able to trade electricity continuously on the day the energy is needed and above all swiftly respond to unexpected changes in consumption and outages. SIDC is a follow-up of the Cross Border Intraday (XBID) Project which delivered the first technical solution for creating SIDC.

SIDC expands in waves. SEPS joined SIDC within the fourth wave in November 2022.

Project IGCC (International Grid Control Cooperation)

The implementation project IGCC (International Grid Control Cooperation) aims to create the European platform for the exchange of imbalances in the real time (Imbalance Netting) according to Regulation (EU) 2017/2195 establishing a guideline on electricity balancing.

SEPS actively participates in IGCC since May 2020.

Project MARI and PICASSO

Both implementation projects aim to create the European platform for the exchange of balancing energy from frequency restoration reserves with manual activation (Manually Activated Reserves Initiative, MARI) or automatic activation (Platform for the International Coordination of Automated frequency restoration and Stable System Operation, PICASSO) according to Regulation (EU) 2017/2195 establishing a guideline on electricity balancing.

SEPS participates on both projects since June 2018.



TSC (TSO Security Cooperation)

TSC (Transmission System Operator Security Cooperation) predstavuje platformu pre regionálnu spoluprácu PPS s cieľom zlepšiť bezpečnosť prevádzky prenosových sústav participujúcich krajín. Najvýznamnejšou iniciatívou TSC bolo založenie spoločnosti TSCNET Services GmbH.


CIGRE is an international non-profit association for promoting cooperation of experts from all over the world to disseminate knowledge to improve power systems of today and tomorrow. The main objectives of the association are to design and deploy future power systems, optimize existing equipment and power systems, respect environmental requirements, and enable access to information. CIGRE provides technical knowledge through events, permanent technical studies (experts from all over the world collaborate on structured programs), publications and articles.