Unit 5 of the coal-fired Sostanj thermal power plant is scheduled for permanent retirement in June next year, ending 48 years of continuous operation. Since it began service, the unit has generated approximately 71,207 GWh of electricity, significantly contributing to Slovenia’s energy supply.
In line with legislation aimed at accelerating the transition away from coal, unit 5 was placed into cold standby on 1 January this year. After a successful planned overhaul of its gas turbines, the decision has been made to permanently cease operations. This marks the retirement of another legacy block at TPP Sostanj, which has long been a cornerstone of the country’s electricity production.
According to TPP Sostanj Director Branko Debeljak, preparations for the shutdown are already underway. In September, crews will begin refurbishing the first of two 42 MW gas turbines, with work on the second turbine to follow. Both overhauls are expected to be completed by June 2026, when unit 5 will be officially decommissioned.
The history of unit 5 dates back to a construction tender in 1973 and a cornerstone ceremony in February 1975. The unit was first synchronized to the grid on 25 September 1977. Although initially planned to retire once unit 6 came online, pressing energy demands kept unit 5 on standby until now.
