Hydropower generation across South-East Europe climbed sharply in calendar week 13, delivering short-term balancing support while regional supply conditions remained fragmented. Output rose by 17.35% or +553.5 GWh, but the improvement did not spread evenly across national systems. For grid operators and market participants, the pattern underscores how quickly operational flexibility can shift when hydrological conditions diverge between neighbouring countries.
Week 13 gains led by Türkiye
Türkiye drove most of the increase, with hydropower output up 28.24% or +607.7 GWh. The scale of the rebound points to either improved reservoir inflows or stronger dispatch from hydro facilities during the period. That additional generation helped strengthen the regional supply balance at a time when other markets were not moving in the same direction.
Western Balkans see meaningful support despite low baselines
Croatia and Serbia also recorded pronounced increases, with hydropower generation rising by 244.26% and 153.98%, respectively. Although these percentage jumps came from relatively low starting points, they still translated into tangible operational support for local systems. In practical terms for system balancing, additional hydro output can reduce the need to rely on higher-cost thermal generation during tight intervals.
Greece and Bulgaria fall as river-basin conditions split
Not all markets benefited from the same hydrological momentum. Greece saw hydropower output decline by 38.67%, while Bulgaria fell by 23.48%. Italy and Romania registered smaller reductions as well, reinforcing that weekly outcomes were shaped by localized rainfall patterns and reservoir management choices rather than a uniform weather signal.
Implications for balancing, pricing signals, and planning assumptions
The divergence matters for how short-term system tightness is managed, particularly in markets where hydro contributes to balancing services. With more hydro available in parts of the region, higher-cost generation was displaced, contributing to modest price declines observed during the week. At the same time, traders highlighted that hydro’s variability limits its value as a dependable long-term stabilizing factor because seasonal and climatic conditions can change quickly.
As South-East Europe moves into spring and early summer, hydro output is expected to remain an important operational variable, especially across the Western Balkans. However, the degree of impact will depend on rainfall timing and how reservoirs are managed over coming weeks. For developers and investors tracking renewable integration and grid modernization needs, the episode reinforces that dispatchable renewable generation can provide near-term relief, but planning for reliability must still account for hydrology-driven uncertainty alongside other weather-dependent resources.