On 6 September 2018 the Šoštanj Thermal Power Plant (TEŠ) produced a total of 18,811,373 kWh of electricity, which is its highest daily production ever. The power plant achieved the record daily production of electricity with generators 5 and 6. Generator 6 produced 12,229,355 kWh, and generator 5 produced 6.582.018 kWh of electricity.

The highest daily production, achieved on 6 September, exceeded the previous record daily production of electricity by 213,707 kWh. TEŠ achieved the previous record of 18,597,666 kWh on 22 December 2016 with the coal-powered generators 6 and 4 and with the gas-powered generator. Generator 4 is no longer in operation, as it was permanently shut down this summer due to outdatedness, while generator 5 has been operational again since August after undergoing ecological rehabilitation.