The Southeast European day-ahead electricity market opened Tuesday with a summer pattern of strong solar generation around midday, followed by constrained thermal and nuclear availability outside solar hours. Weak hydrological conditions added pressure, alongside an increasingly costly evening ramp. Prices did not move uniformly across the region, with Slovenia, Italy, Croatia and Romania posting the highest baseload levels while Greece, Bulgaria, Albania and Montenegro traded significantly lower.
Market conditions reflected a structural challenge for regional power systems as solar penetration increases. Daylight hours can see higher supply from solar generation, while dispatchable resources remain limited and hydro flexibility is reduced. The evening transition becomes the key exposure point when solar output disappears and demand remains elevated.
Baseload price spread widens across major SEE markets
Hungary’s HUPX baseload price rose by €8.30/MWh to €186.90/MWh, up 4.6% on the day. Romania settled at €188.24/MWh, while Slovenia recorded the highest directly observed Southeast European level at €194.61/MWh. Croatia followed at €191.92/MWh and Italy’s national day-ahead market reached €194.94/MWh.
Lower prices were recorded in southern markets, with Greece at €155.03/MWh, Bulgaria at €157.03/MWh, Albania at €153.56/MWh and Montenegro at €159.55/MWh. North Macedonia increased to €165.43/MWh, while Serbia remained near the middle of the regional curve at €174.64/MWh.
The difference between the highest and lowest major SEE markets reached €41.05/MWh between Slovenia and Albania. Including Germany and Italy, the gap widened to €45.15/MWh. The separation reflected cross-border transmission capacity that was not sufficient to fully balance regional electricity values during the evening scarcity period.
Hourly scarcity concentrates around H20
Daily baseload averages did not capture the scale of the hourly imbalance. HUPX fell to a minimum of €76.50/MWh at H14 when solar production was strongest before rising sharply to €418.90/MWh at H20. Romania followed a similar profile, reaching €433.90/MWh at H20.
Slovenia showed the strongest evening increase, peaking at €507.60/MWh during the same window. Croatia reached €478.80/MWh and Serbia climbed to €496.80/MWh around H20. For comparison, Germany peaked at €240/MWh, Austria at €245.40/MWh and Italy’s national market at €267.40/MWh.
The pattern indicated that pressure was concentrated in a corridor linking Hungary, Romania and parts of the Western Balkans where flexible supply was more limited than elsewhere in the region.
Demand rises while net imports fall but remain important
Regional electricity consumption was forecast at an average of 34,191 MW, up 1,445 MW or 4.4% versus Monday as temperatures rose by almost 1°C across the region. Greece was expected to average 28.6°C.
Hungary’s consumption stayed relatively stable at 5,023 MW, while demand increased in several larger SEE markets including Romania at 5,923 MW, Greece at 7,251 MW, Serbia at 4,030 MW and Croatia at 2,589 MW. Higher consumption combined with weak hydro conditions and limited flexible generation continued to add pressure on regional balances.
Estimated regional generation increased to 32,604 MW, about 5.2% higher than Monday, reducing net imports from 1,740 MW to 1,587 MW despite stronger demand. Imports still covered around 4.6% of total regional demand.
Structural deficits vary by country
The regional average deficit masked differences between individual markets. Hungary remained the largest structural importer with average imports of 2,269 MW, equivalent to about 45% of domestic consumption.
Croatia imported 1,197 MW, representing more than 46% of demand, while Serbia recorded a deficit of 496 MW and Romania imported 437 MW. Montenegro imported 305 MW, Slovenia imported 84 MW and Kosovo imported 142 MW.
Montenegro faced the largest relative supply gap with imports covering almost 62% of forecast consumption; domestic generation was estimated at only 187 MW against demand of 492 MW. Montenegro’s BELEN day-ahead price fell by €36.60/MWh to €159.55/MWh without reflecting stronger domestic supply conditions.
Price levels in Montenegro were influenced by surrounding import availability and pricing, including flows from Bosnia and Herzegovina, Serbia and Albania as well as the Italian interconnector.
Cross-border flows shape balances for deficit and transit markets
Bulgaria and Greece remained key southeastern export sources in expected flows for Tuesday. Bulgaria was expected to export 1,425 MW, equivalent to more than 36% of domestic consumption, while Greece’s net exports reached 1,506 MW, or about 21% of demand.
Bosnia and Herzegovina exported 245 MW and North Macedonia exported 157 MW; Albania recorded a marginal export position of 10 MW.
Northern imports from Austria and Slovakia into Hungary and Slovenia averaged 2,475 MW, around 7.4% lower than Monday. Bulgaria supplied approximately 1,536 MW towards Romania and 366 MW towards Serbia.
Greece exported 456 MW towards Bulgaria, 433 MW towards North Macedonia and 157 MW towards Albania before sending the full scheduled 500 MW towards Italy.
Romania shifts between import deficit and export during peak hours
Romania operated both as a deficit market and a transit hub during the day-ahead period described for Tuesday trading conditions. While importing electricity from Bulgaria it also exported electricity toward Hungary and Moldova.
Romania exported 953 MW towards Hungary and 237 MW towards Moldova while maintaining an average net import position of 437 MW. The direction of flows changed significantly throughout the day.
During peak hours Romania moved into a net export position of 109 MW, while during lower-demand periods it imported almost 984 MW. The shift was linked to interaction between Romanian solar production, Bulgarian exports and tighter conditions in Hungary.
Solar changes off-peak dynamics alongside generation mix shifts
The peak versus off-peak distinction became less useful under current summer market structure because “off-peak” hours after sunset could still face rising system pressure as solar output falls while demand rises from residential and commercial sectors.
Hungary’s average import position was 2,269 MW, but imports increased to 3,096 MW during off-peak hours compared with 1,441 MW during peak periods.
The generation mix supported the pricing pattern: regional coal generation increased by 1,235 MW to 7,034 MW, while gas-fired generation rose by 766 MW to 5,408 MW. Hydropower output improved by 778 MW to 5,451 MW, but remained below levels needed for normal flexibility requirements.
Solar production increased to 7,471 MW, while wind declined by 832 MW to only 1,747 MW. Nuclear generation remained weak at 3,348 MW, limiting stable low-carbon baseload availability during evening transition hours.
Nuclear output limits flexibility in Hungary; Tuesday forecasts show stronger solar but weak wind