Cross-border electricity trading across Southeast Europe weakened during Week 26 even as regional power demand rose sharply. Net cross-border electricity trade fell by 6.0% to 972 GWh, while electricity consumption increased by 12.7% to 18.41 TWh. With demand higher, many markets relied more on domestic generation rather than additional imports.
The change was associated with a 24.7% increase in regional thermal generation, which reached 6.52 TWh. Output from gas, coal and lignite-fired plants rose, supporting system supply during the period. Wholesale electricity prices moved higher alongside the shift toward domestic dispatch.
Domestic thermal dispatch versus import demand
Italy remained the region’s largest net importer, though its net imports declined by 9.3% to 1.02 TWh. Croatia also reduced net imports by 5.5%, despite a significant rise in electricity demand. Consumption increased by 22.9% in Italy and 15.5% in Croatia.
In both countries, the additional load was met largely through stronger domestic thermal generation instead of higher cross-border purchases. Elsewhere, trading patterns diverged as some systems adjusted through imports while others increased domestic output. The week’s outcomes reflected differences in supply conditions across national markets.
Net import changes across Greece, Romania, Hungary and Serbia
Greece increased net electricity imports by 54.0%, reaching 254 GWh. Romania and Hungary relied more on external supplies, with net imports rising by 150.9% and 60.7%, respectively. These changes contrasted with the reductions seen in Italy and Croatia.
Serbia moved from being a net exporter to a marginal net importer during the week. Bulgaria maintained its position as a major regional exporter, while Türkiye continued to post stable net export volumes. Together, these shifts show that cross-border flows did not move uniformly across the region.
Implications for trading and system flexibility
The week’s figures indicate that Southeast Europe operates as multiple national markets rather than a single import-dependent system. Country-level conditions during the heatwave differed according to generation availability, renewable output, hydro resources and price differentials. Some systems covered higher demand through increased domestic thermal production, while others turned to imports.
The cross-border trading environment became more complex for market participants as relative price levels changed across countries. Elevated prices in Hungary and Romania contrasted with comparatively lower prices in Bulgaria and Greece, alongside Italy’s continued import requirements and Serbia’s changing position. The potential value of cross-border opportunities also depended on transmission capacity, network congestion, scheduled power flows and hourly price movements.
The reduction in regional electricity trade during surging demand also pointed to the role of domestic flexibility and dispatchable generation for system planning. When heatwaves affect multiple countries at once, cross-border imports cannot always offset widespread supply pressures elsewhere in the region. Interconnections remain relevant, but their effectiveness depends on whether surplus generation is available beyond national borders.
Week 26 showed that although Southeast Europe’s interconnected market remained active, cross-border trading alone did not remove the need for strong domestic generation and system resilience during peak demand periods.