HSE forecasts sharp July decline on Drava, Soča and lower Sava
Holding Slovenske Elektrarne expects July hydropower production from the Drava, Soča and lower Sava river systems to be 39% lower than July 2025. The company also projects output to be approximately 52% below the five-year monthly average. The forecast links the contraction to drought conditions and exceptionally low river levels affecting generation plants.
June strength gives way to weaker rainfall and higher evaporation
The expected deterioration follows a comparatively strong June, when hydropower output was 4% higher year on year. River conditions weakened after that as rainfall stayed limited. High temperatures increased evaporation, contributing to reduced water availability for generation.
First-half 2026 underperformance points to broader hydrological deficit
Across the first half of 2026, production from HSE’s hydropower plants was 31% below the same period of 2025. It was also 38% below the five-year average. The figures indicate that July weakness is part of a wider hydrological shortfall rather than a single-month disruption.
Low flows near decade lows; heatwave risk for river levels
By the end of July, flows on the Drava, Sava, Soča and most other major rivers were close to the lowest levels recorded for that month over the past decade. Another heatwave is expected to last at least ten days. Further reductions in flows are possible if temperatures remain elevated.
Market implications for flexibility, imports and regional dispatchable supply
Lower hydroelectric production reduces Slovenia’s normally flexible generation position. It also increases sensitivity to imported electricity. Dispatchable renewable output is additionally removed from a regional market already affected by poor hydrology in Serbia and cooling-water concerns along the Danube.
Financial exposure depends on hedges, import costs and trading performance
The financial effect on HSE depends on hedge coverage, import costs and the performance of its trading portfolio. Hydrological losses can be particularly costly when they coincide with high regional evening prices. In those hours, HSE loses production during periods when flexible hydro capacity would otherwise capture its highest value.
