Cross-border electricity trading across Southeast Europe weakened during Week 26 despite a sharp increase in regional power demand, highlighting the growing importance of domestic generation during periods of system stress. Net cross-border electricity trade declined by 6.0% to 972 GWh, even as electricity consumption climbed 12.7% to 18.41 TWh. Rather than relying on additional imports to meet rising demand, many countries turned to higher levels of domestic electricity production, particularly from thermal power plants.
The shift was driven by a 24.7% increase in regional thermal generation, which reached 6.52 TWh as gas, coal and lignite-fired plants boosted output. This stronger domestic dispatch reduced dependence on imported electricity in several markets, even as wholesale electricity prices moved higher. Instead of easing market pressure, the region relied more heavily on its own, often more expensive, generation resources to maintain supply.
Italy remained Southeast Europe’s largest net electricity importer, although its net imports fell 9.3% to 1.02 TWh. Croatia also reduced net imports by 5.5%, despite experiencing a significant increase in electricity demand. Consumption surged 22.9% in Italy and 15.5% in Croatia, with both countries meeting much of the additional load through stronger domestic thermal generation rather than increased cross-border purchases.
Elsewhere, market dynamics differed considerably. Greece increased net electricity imports by 54.0% to 254 GWh, while Romania and Hungary relied more heavily on external supplies, with net imports rising 150.9% and 60.7%, respectively. Serbia shifted from being a net exporter to a marginal net importer during the week, whereas Bulgaria maintained its role as a major regional exporter and Türkiye continued to post stable net export volumes.
These contrasting trading patterns underline that Southeast Europe cannot be viewed as a single import-dependent electricity market. Each country entered the heatwave under different conditions, shaped by generation availability, renewable output, hydro resources and price differentials. While some systems covered higher demand through increased domestic thermal production, others turned to imports, and a number of countries were able to maintain export positions thanks to stronger generation portfolios.
For electricity traders, the evolving market created a more complex environment for cross-border opportunities. Elevated prices in Hungary and Romania, comparatively lower prices in Bulgaria and Greece, Italy’s continued import requirements and Serbia’s changing market position all influenced regional trading strategies. However, the value of these opportunities remained closely linked to transmission capacity, network congestion, scheduled power flows and hourly price movements, factors that weekly averages cannot fully capture.
From a system planning perspective, the decline in regional electricity trade during a period of surging demand reinforces the importance of domestic flexibility and dispatchable generation. When heatwaves affect multiple countries simultaneously, cross-border imports cannot always compensate for widespread supply pressures. Interconnections remain valuable, but their effectiveness depends on surplus generation being available elsewhere in the region. During periods of widespread heat stress, electricity markets increasingly reflect the scarcity of reliable generation capacity.
Week 26 demonstrated that while Southeast Europe’s interconnected electricity market remains highly active, cross-border trading alone cannot replace the need for strong domestic generation and system resilience during periods of peak demand.