Southeast European day-ahead power prices rebounded sharply for Monday delivery, but the move produced renewed market fragmentation rather than broad regional convergence, with Serbia emerging as the clear premium market.
SEEPEX jumped €130.4/MWh day on day to €190.54/MWh, placing Serbia €14.17/MWh above Hungary, almost €29/MWh above Bulgaria and more than €48/MWh above Greece and Montenegro. HUPX, OPCOM and CROPEX formed a relatively tight central cluster at €176.38/MWh, €175.71/MWh and €176.84/MWh, respectively, while Slovenia settled slightly higher at €179.82/MWh.
The southern markets remained considerably softer. Bulgaria cleared at €161.65/MWh, North Macedonia at €158.31/MWh, Albania at €168.12/MWh, Greece at €142.34/MWh and Montenegro at only €140.95/MWh. Italy remained the regional high at €218.93/MWh, maintaining a strong westward price pull.
The Monday rebound was primarily associated with the return of weekday load. Combined Hungary-SEE consumption rose about 3.1 GW from Sunday to 30.77 GW, while regional generation recovered to roughly 30.20 GW. Despite higher demand, the aggregate net-import requirement fell to only 568 MW, compared with 1.26 GW a day earlier.
The important signal for traders was therefore not regional scarcity but where the available generation was located and whether cross-border capacity could move it toward the higher-priced zones.
Serbia remained the clearest deficit market. Average consumption increased to 3,518 MW, while generation reached only 2,913 MW, leaving the system around 605 MW net short. Domestic generation rose by just 84 MW from Sunday while demand increased by almost 290 MW, materially widening Serbia’s dependence on imports.
Bulgaria was one of the main suppliers. Bulgarian flows towards Serbia averaged about 336 MW, increasing to 393 MW during peak hours, while Romania supplied Serbia by about 114 MW on average and 321 MW during peak hours.
The Serbia-Hungary route was more significant for the price formation signal. Recorded commercial flows were zero throughout all 24 hours on Sept. 7, after substantial two-way trading on preceding days.
That separation helps explain why SEEPEX detached sharply from HUPX despite Hungary itself trading at a relatively elevated €176.38/MWh.
Romania, by contrast, sat almost exactly on the Hungarian price at €175.71/MWh, only €0.67/MWh below HUPX, indicating strong price coupling despite large changes in hourly Romanian-Hungarian flows. Bulgaria retained a €14.73/MWh discount to Hungary, reflecting a much stronger domestic balance and substantial export availability.
At the southern end of the curve, Montenegro remained anomalously cheap. BELEN settled €35.43/MWh below HUPX even though Montenegro itself was around 68 MW net short. The country imported from surrounding Balkan systems while simultaneously sending an average 539 MW towards Italy, where day-ahead prices were nearly €78/MWh higher. The pattern underlines Montenegro’s role as both a domestic deficit system and a transit corridor feeding the Italian premium market.
Cross-border signal
The broader Hungary-SEE region imported around 1.63 GW from Austria and Slovakia, but approximately 1.43 GW was simultaneously moving toward Italy. Regional balance therefore remained heavily shaped by transit rather than simple aggregate shortage.
The resulting market structure was clear:
Serbia represented the scarcity premium, Hungary-Romania-Croatia-Slovenia formed the central price cluster, Bulgaria and North Macedonia provided the intermediate discount, while Greece and Montenegro remained the low-price southern zone.
Italy continued to provide the strongest external pull at €218.93/MWh.
Next-session signal
The immediate risk is that SEEPEX retains a premium if Serbia’s import requirement stays around current levels while Hungarian access remains constrained. Even moderate additional Serbian demand could therefore translate quickly into higher SEEPEX spreads rather than being absorbed through regional convergence.
Conversely, Bulgaria’s substantial export position provides downward pressure on the eastern SEE complex and limits the likelihood that the Serbian premium automatically spreads into Romania and Bulgaria.
Renewable conditions do not point to a major near-term supply boost. Regional solar was forecast broadly flat around 6.14 GW, while wind was expected to decline by roughly 233 MW.
The trading focus for the next session should therefore remain on Serbian import availability, Bulgaria-to-Serbia and Romania-to-Serbia flows, restoration of Serbia-Hungary commercial exchange, and the strength of the Italian premium.
For now, the main market signal is one of congestion-driven fragmentation rather than region-wide generation scarcity: adequate power exists across SEE, but transmission availability is determining which markets can access it and at what price.