ENTSO-E reported on the progress of Phase 3 of the trial synchronous operation of the Turkish power system. The aim of the trial operation is to examine the real behavior of the system, to detect any threats unforeseen by the simulation studies, and to identify and implement appropriate countermeasures.

ENTSO-E's Regional Group Continental Europe monitors the performance of the Turkish power system and detects any negative impact it may have on power systems in the region. A range of specific countermeasures have been identified that the Turkish Electricity Transmission Corp. will have to implement under a specific time schedule.

Interconnection of the new power system to the synchronous area of Continental Europe is a serious technical challenge requiring intensive, detailed studies and significant adjustments to the Turkish transmission and generation infrastructure in order to meet the technical standards and to ensure stable operation of the interconnected area.

As a result of these findings, ENTSO-E extended the third phase by one year (fall 2013). The decision taken by ENTOS-E transmission system operators (TSOs), representing the Continental European synchronous area, was based on a technical evaluation of the trial period that previously had been extended to Sept. 18, 2012.

On Sept. 18, 2010, the Turkish power system was synchronized to the interconnected power systems of Continental Europe, marking the start of the parallel trial interconnection as agreed between the Turkish system operator and ENTSO-E's TSOs HTSO, ESO-EAD, Amprion and Tennet GmbH (formerly Transpower). The parallel operation is achieved by two 400-kV lines to the Bulgarian system and by one 400-kV line to the Greek system.

This trial parallel operation period is organized in three phases, the first two of which have been completed. Phase 1 was the stabilization period with no scheduled exchange of energy. Phase 2 consisted of the physical noncommercial energy exchanges between the Turkish system operator and, respectively, the Bulgarian and Greek TSOs in both directions and at both borders. Thus, physical electricity exchange takes place without any trading involved.

Upon successful completion of Phases 1 and 2, Phase 3 consists of limited capacity allocation for commercial electricity exchanges between Turkey and ENTSO-E's Continental Europe synchronous area are allowed, according to procedures mutually agreed between Bulgaria, Greece and Turkey, and in line with European Union rules and ENTSO-E procedures.

For more information, visit www.entsoe.eu.