Cross-border electricity trade became more important in Southeast Europe during Week 23, as higher demand and weaker variable renewables forced markets to rely more heavily on regional balancing. Net imports across SEE increased 9.1% week on week to 1.22 TWh, confirming that interconnectors remain central to system stability and price formation.
The increase in net imports came during a week when regional electricity demand rose 8.2% to 15.15 TWh and variable renewable generation declined 8.9%. That combination created a larger balancing requirement. Hydro and thermal generation both increased, but not evenly across countries. As a result, cross-border flows became a key adjustment mechanism.
Hungary recorded the largest increase among major importing markets, with net imports rising 64.7% to 179.75 GWh. This is significant because Hungary was also one of the more expensive SEE markets, with a weekly average day-ahead price of €103.15/MWh. Higher import reliance suggests that Hungary needed external supply to manage its domestic balance, even as its average price softened 2.0% week on week.
Romania increased net imports by 34.0%, while Croatia raised imports by 18.5%. Both markets faced weaker renewable output, and Croatia also recorded a sharp fall in wind generation despite stronger hydro. These flow movements show how quickly countries can shift from domestic balancing toward cross-border dependence when renewable profiles deteriorate.
Italy remained the largest net importer in the region, with 950.91 GWh of net imports, although this was 14.1% lower than the previous week. Italy’s reduced import requirement suggests improved domestic supply availability, helped by internal generation changes and lower demand. Yet Italy still held the highest SEE weekly price at €128.09/MWh, showing that even lower import dependence did not remove its structural premium.
Greece remained a net exporter, exporting 169.69 GWh, although its exports fell 29.5% week on week. Greece’s position is particularly important because it was cheaper than most SEE markets, with a weekly average of €89.25/MWh. Lower Greek exports may have reduced downward pressure on neighbouring markets and contributed to the fragmented regional pricing pattern.
Türkiye also remained a net exporter, but exports declined 13.6%. This was expected given the country’s 31.0% demand surge. What is notable is that Türkiye was still able to export despite the sharp increase in consumption. Strong hydro output, a large thermal ramp and higher solar production helped preserve its surplus position.
The flow map in the report underlines how interconnected the SEE system has become. Power moved across the Balkan corridor through Hungary, Romania, Serbia, Bulgaria, Greece, Croatia and neighbouring Central European markets. The flow pattern shows that SEE price formation is not purely domestic. It depends on interconnector capacity, scheduled exchanges, neighbouring price spreads and local supply-demand imbalances.
For traders, the flow data create several market implications. First, import-dependent markets such as Italy, Hungary, Romania and Croatia remain exposed to regional scarcity and interconnector constraints. Second, exporters such as Greece and Türkiye can influence neighbouring price formation, but only when surplus volumes are available and network capacity allows flows. Third, hydro and renewable variability can quickly alter a country’s net position from week to week.
The Italy position remains the most important for regional spread analysis. Even after reducing imports 14.1%, Italy still absorbed nearly 951 GWh of net imports and maintained a price premium of almost €39/MWh over Greece and around €28/MWh over Bulgaria. This confirms Italy’s role as the region’s high-price anchor and a key destination for lower-cost regional power where interconnector capacity permits.
Hungary’s import increase also matters for Central SEE. Higher Hungarian import demand can support prices in neighbouring markets and affect flows from Romania, Croatia, Serbia, Slovakia and Austria. Hungary’s price remained above €100/MWh, keeping it in the upper SEE cluster despite a week-on-week decline.
Cross-border flows also interact with gas risk. If gas prices rise further and gas-fired generation becomes more expensive, countries with available hydro, lignite or renewable surplus may gain export value. Conversely, import-dependent systems may face higher exposure during evening peaks and low-renewable periods. Interconnector availability will therefore become even more valuable as summer demand increases.
Week 23 showed that SEE is not one integrated price zone, but it is increasingly one interconnected balancing area. Local prices still diverge sharply, yet cross-border flows decide how much of that divergence can be arbitraged. The rise in net imports to 1.22 TWh confirms that the region’s dependence on electricity exchanges is increasing as demand, renewable volatility and fuel-price risk become more pronounced.
