Montenegro’s hydroelectricity output fell to around 50 GWh in September, down 36.3% year on year, as drought and low river levels exposed weather-related supply risks in Balkan electricity systems. Slovenia produced 223 GWh of hydroelectricity in September, 32% less than a year earlier.
Serbia entered autumn with higher requirements for electricity imports. Regional import needs rise sharply when hydro output underperforms while thermal or nuclear plants are constrained.
In Romania, low Danube levels impaired cooling-water conditions at the Cernavodă nuclear reactors, which were shut. Bulgaria’s Kozloduy nuclear output has also been monitored against Danube water availability. Drought can therefore reduce hydroelectricity and nominally firm nuclear generation at the same time.
Albania’s power system remains dominated by hydropower, leaving it particularly exposed to rainfall risk. The Spille wind project is a way to diversify supply away from rainfall. Solar power can also broaden generation, but without storage it creates balancing challenges between midday output and evening demand.
Serbia’s Bistrica pumped-storage project is intended to store electricity and release it during periods of scarcity. Pumped storage does not create primary energy: it stores surplus power from wind, solar or imports and releases it when supply is tight. As variable renewable generation grows, it can reduce the cost of drought periods and renewable-energy oversupply.
Winter precipitation could improve electricity supply, but the likelihood of recovery remains uncertain. Combining generation sources with different profiles, storage and interconnection offers more protection than relying on favourable hydrology returning on schedule.
