In annual terms, the country's power output was up 36%, while total consumption rose 4.6%, the office of statistics said in a statement on Monday, citing provisional data.
The September output of the country's hydro power plants rose 117% on the year and was up 7% on a monthly comparison basis to 481 GWh, the output of the thermal power plants was up by an annual 35% and increased by a monthly 5% to 391 GWh, while the electricity production of Slovenia's sole nuclear power plant, Krsko, was up 1% on the year and down 2% on the month to 494 GWh, the statement read.
In September, 521 GWh of electricity was imported and 786 GWh was exported. Imports rose 12% compared to the previous month, while export increased 6%.
In annual terms, Slovenia's electricity exports went up 21%, while imports fell 26%.
Nuclear energy had the largest share of 35.4% in Slovenia's total power production in September, followed by hydro energy with 34.5%, thermal power plants with 28% and solar with 2.0%.