The history of coal-based electricity production at the Brestanica TPP site dates back to 1943. In the mid-1970s, however, with the abandonment of coal and the construction of units 1, 2 and 3, the Brestanica TPP became the first combined gas-steam power plant in the previous country (SFR Yugoslavia). Initially, it used heating oil and primary gasoline as fuel. This type of production, at that time unique in Europe, was introduced due to the need for peak energy and primarily for the safe and reliable operation of the Krško NPP.

With the construction of units 4 and 5, Brestanica TPP, with its additional capacities, intervened in the area of providing key system services in the electric power system of Slovenia. The capacity of these services was later increased with the construction of units 6 and 7. The Brestanica TPP with gas units with a total capacity of 350 MW provides:

• tertiary frequency regulation in the event of failure of larger units,
• units’ start-up without external power supply and the possibility of establishing a network in case of breakdown of the electric power system,
• indirectly, stable operation of the Krško NPP in the event of disturbances in the national electric power system.