Drought and low river levels are exposing weather-related supply risks across Balkan electricity systems, reducing reservoir generation and affecting conditions for nuclear-plant cooling. Reported September figures put Montenegro’s hydro output at around 50 GWh, down 36.3% year on year.
Slovenia produced 223 GWh of hydroelectricity in September, 32% less than a year earlier. Serbia entered autumn with higher requirements for electricity imports, as weaker hydro output can raise import needs sharply when thermal or nuclear plants are constrained.
Low Danube levels impaired cooling-water conditions at Romania’s Cernavodă reactors, which were shut. Bulgaria’s Kozloduy nuclear output has also been monitored against Danube water availability, showing how drought can constrain both renewable hydro and nominally firm nuclear generation in the same regional supply stack.
Albania is particularly exposed because its power system remains dominated by hydropower. The Spille wind project offers a way to diversify supply away from rainfall risk, while solar can also broaden generation but creates midday and evening balancing challenges without storage.
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, then returns it when supply is tight. As variable renewable generation grows, the technology 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.
