Power systems in the region were designed and constructed in different political, economical and technical circumstances. Bulgarian and Romanian system were relied on ex USSR, while Bosnian, Croatian, Serbian, Macedonian, Montenegrin and UNMIK system were designed within ex Yugoslavia. Albanian system was developed independently of others.
Power systems in the region were operated in two electrically separated zones for last 15 years due to war destructions. Croatia and part of Bosnia and Herzegovina were working synchronously with UCTE while other part of Bosnia and Herzegovina, Serbia and Montenegro, FYROM, Albania, Romania, Bulgaria and Greece were working synchronously isolated from UCTE. Re-connection of two UCTE zones was performed in October 2004 after SS Ernestinovo and SS Mostar reconstruction/reparation, so technical prerequisites for market competition were achieved. Transmission
network in the region (including Greece) operates under 750 kV, 400 kV, 220 kV, 150 kV and 110 kV voltage levels. 400 kV and 220 kV networks are well meshed due to many interconnection lines. There are two 750 kV, twenty one 400 kV and sixteen 220 kV interconnection lines in the region today.
Different production facilities exist in the region (thermal, nuclear, hydro) [1]. Some countries produces electricity mostly from hydro sources (Albania, Montenegro), some produces electricity mostly from thermal units (Romania, Bulgaria, Serbia, FYR of Macedonia), while generation mix is quite equaled (hydro versus thermal) in Croatia and Bosnia and Herzegovina. Other electricity sources, including renewables, haven
