The softening of SEE day-ahead prices in Week 24 concealed a more complex generation story. While renewable output increased and prices fell across most markets, hydropower generation weakened sharply, forcing thermal plants to cover a larger share of regional demand.
Regional hydropower generation declined by 300.2 GWh, or 7.5%, to 3.70 TWh. Türkiye was the main driver, with hydro output down 229 GWh, or 8.6%, accounting for more than three-quarters of the regional fall. Bulgaria also recorded a sharp hydro decline of 42.9 GWh, or 21.8%, while Greece, Italy, Romania and Serbia posted smaller reductions.
The thermal response was immediate. Thermal generation across the SEE region rose by 362.6 GWh, or 8.7%, to 4.52 TWh. Coal and lignite generation increased by 420.6 GWh, or 24.4%, reaching 2.14 TWh. Gas-fired generation moved lower, falling by 58.0 GWh, or 2.4%, to 2.38 TWh.
This shift matters because it shows where system flexibility came from. The region absorbed higher demand and lower hydro output not through gas alone, but through a pronounced coal and lignite increase. Türkiye added 260.6 GWh of coal-fired output, Italy added 81.2 GWh, and Serbia added 66.0 GWh. Bulgaria and Romania also recorded gains.
Greece was the main exception. Its thermal generation fell 6.3%, even as demand increased, because lower lignite and gas generation more than offset stronger consumption. Croatia also differed from the wider pattern, with hydropower rising 43.5%.
The commercial reading is that SEE prices can soften under strong renewables, but system security still rests heavily on dispatchable thermal capacity when hydro weakens. For industrial offtakers and banks assessing renewable PPAs, that distinction is important: lower spot prices do not automatically mean lower carbon intensity or lower balancing risk.
