Cross-border electricity flows point to intermittent coupling between SEE and Central Europe

Cross-border electricity flows in South-East Europe are increasingly mirroring structural changes in the regional power system, with recent evidence pointing to a shift toward partial market coupling with Central Europe. For traders and investors, the implication is clear: the region is becoming more interconnected, but not in a way that eliminates price volatility—especially when demand rises and renewable generation fades.

Price alignment improves—renewables are the main driver

In week 16, the Hungary–Germany price spread narrowed sharply to €1.38/MWh, signalling near convergence between the two markets. The level of alignment has not been seen since August 2025. According to the data, this shift is primarily linked to increased renewable generation within SEE rather than any meaningful change in interconnection capacity.

CORE imports fall as midday solar exports rise

At the same time, imports from the CORE region declined to one of their lowest levels since early 2025. The drop was particularly pronounced during midday hours when solar output across SEE markets was at its peak. In several instances, flows reversed direction—reflecting excess generation being exported toward neighbouring regions instead of being absorbed locally.

Evening peaks keep divergence alive

Despite these signs of coupling, the picture is not uniform across the day. During evening peak hours—when demand increases and renewable output falls—SEE markets continue to rely on imports. That pattern leads to renewed price divergence, reinforcing a hybrid market structure in which coupling occurs intermittently rather than continuously.

Transmission constraints still shape outcomes

Transmission constraints remain a central limiting factor. While cross-border capacity improvements have been observed, they have not been sufficient to fully integrate SEE markets into the broader European system. Congestion during critical hours continues to influence both price formation and flow patterns.

Exports to Ukraine and Moldova continue for stability

Flows toward Ukraine and Moldova remain a consistent feature of regional trading dynamics. Exports have continued for the 29th consecutive week, providing an additional outlet for excess generation—particularly during periods of peak demand—and helping mitigate extreme price movements.

Taken together, the evolving flow dynamics suggest SEE markets are moving toward a more integrated system while remaining highly sensitive to physical constraints and renewable variability. That combination can create opportunities for cross-border trading strategies designed to exploit intraday differences between supply and demand.