In June 2025, hydropower plants on Slovenia’s Drava, Sava, and Soča rivers delivered 341 GWh of electricity to the transmission network—just over 60% of the volume produced in June 2024 and 18% below initial forecasts.
The decline was most pronounced in the Sava basin, where reduced rainfall significantly impacted production. Power plants on the upper and lower Sava generated only 43.3 GWh, a decrease of 65.2 GWh—or more than 60%—compared to the same month last year.
Drava and Soča hydropower plants were also affected by unfavorable hydrological conditions, though to a lesser extent. The Drava plants produced 245.7 GWh in June, a 35.2% year-on-year drop, while the Soča system generated 52 GWh, down 31.3% from June 2024.
Although 2025’s hydropower performance has been weaker than last year’s, it’s important to note that 2024 was exceptionally favorable for hydro production. Hydropower plants exceeded their annual targets well before year-end. In the first half of 2025, total hydropower output reached just over 2,100 GWh—about 25% less than in the same period of 2024 but still more than 8% above long-term average projections.
