Southeast Europe’s day-ahead electricity market tightened on Wednesday as cooling demand rose while nuclear availability fell in Hungary and Romania. Prices increased across much of the central and western region, while Greece and Bulgaria saw lower levels supported by renewable generation.
Spot price moves across Southeast Europe
The largest increase was recorded in Serbia, where the SEEPEX baseload price rose by €29.0/MWh to €145.50/MWh. The Serbian level was €13.16/MWh above Hungary and higher than neighbouring markets except Albania. Croatia gained €23.3/MWh to €138.73/MWh, while Romania increased by €22.1/MWh to €132.87/MWh.
Slovenia added €16.4/MWh to reach €141.83/MWh, and Montenegro advanced by €15.7/MWh to €140.79/MWh. Hungary’s HUPX benchmark increased by €10.3/MWh to €132.34/MWh, staying close to Germany where the day-ahead price reached €126.84/MWh.
In contrast, Greece and Bulgaria recorded lower prices on the back of strong renewables output. Greece fell by €11.2/MWh to €95.79/MWh, while Bulgaria declined by €4.4/MWh to €102.59/MWh.
Regional price gaps and the role of renewables
Albania remained the most expensive regional market with a baseload price of €148.19/MWh, despite a daily decrease of €10.1/MWh. North Macedonia increased by €7.2/MWh to €114.71/MWh, while Italy held the regional premium at €177.13/MWh.
The Greece-Hungary spread widened as Greece traded at €36.55/MWh below Hungary and almost €50/MWh below Serbia, reflecting high solar and wind availability .
Nuclear availability falls along the Danube
The main factor behind the price surge was reduced nuclear availability along the Danube corridor . Hungary’s Paks plant cut output at unit 1 by around 254 MW due to exceptionally low river levels affecting cooling conditions.
At the same time, Romanian operator Nuclearelectrica placed Cernavoda unit 1 into a controlled shutdown . Combined regional nuclear output fell by 542 MW from 5,560 MW to 5,018 MW.
Hungarian nuclear output dropped from 1,834 MW to 1,577 MW, while Romanian production declined from 1,165 MW to 880 MW . The full effect of the Romanian outage was expected to show up in Wednesday’s physical balance because the shutdown began during Tuesday.
Demand rises as river conditions remain a constraint
The nuclear reduction coincided with higher electricity demand forecast for the region at 32,490 MW, up 1,417 MW versus Tuesday . Higher consumption forecasts were recorded for Hungary, Greece, Romania, Bulgaria, Slovenia and Croatia as temperatures continued to rise and cooling demand increased.
Solar generation was expected at 7,417 MW and wind output at 2,455 MW . Renewables helped create deep midday price declines but did not remove scarcity risk during evening hours after solar output faded.
Day-night spread widens during evening ramp hours
The imbalance between daytime and evening conditions drove strong differences in hourly pricing . In Hungary, peak prices averaged €92.00/MWh while off-peak prices reached €172.60/MWh.
The minimum price in Hungary was €11.80/MWh at hour 14 before rising to €267.60/MWh at hour 21 . Germany followed a similar pattern with prices moving from €0/MWh during the afternoon to €263.60/MWh in the evening.
The evening spike was more pronounced in Slovenia and Croatia . BSP reached €305.10/MWh at hour 20 and CROPEX peaked at €289.90/MWh.
Tight structures in Serbia and Croatia; Montenegro supports exports
Serbia also showed a tight market structure with SEEPEX remaining above €45.00/MWh throughout the day before rising to €251.10/MWh at hour 21 . Serbian peakload averaged €112.90/MWh while off-peak prices reached €178.00/MWh.
Serbian consumption was forecast at 3,457 MW compared with domestic generation of 2,593 MW, implying average net imports of 865 MW . Imports increased during peak hours to 1,173 MW with supply mainly from Romania, North Macedonia, Croatia, Bulgaria and Bosnia and Herzegovina.
The import dependence helped explain the SEEPEX premium over HUPX of €13.16/MWh . Cross-border capacity availability became a key factor as Romanian nuclear availability fell and Croatian import demand increased.
Croatia faced an even tighter balance with consumption rising to 2,369 MW against domestic generation of 1,228 MW . Average imports were required at 1,142 MW including about 1,065 MW from Hungary.
Montenegro, meanwhile, remained a net importer with consumption of 447 MW and generation of 320 MW . Exports through the submarine interconnector to Italy continued to support a BELEN price of €140.79/MWh.
Cernavoda outage shifts Romania toward net imports; Bulgaria stays surplus; Greece exports more power
Romania recorded the largest market-position reversal moving from an average net export position of 350 MW on Tuesday to expected net imports around 450 MW . Generation declined to 5,036 MW while consumption increased to 5,486 MW.
Bulgaria supplied approximately 1,266 MW to Romania as it compensated for lost nuclear output . This shift explained a €22.1/MWh increase in OPCOM and Romania’s slight premium over HUPX.
Bulgaria remained the region’s main surplus market producing around 5,047 MW versus consumption of 3,915 MW . It exported about 1,266 MW to Romania, 294 MW to North Macedonia and 101 MW to Serbia while importing 517 MW from Greece.
Kozloduy-supported nuclear production together with strong solar availability supported Bulgaria’s lower price level . In Greece, generation was about 8,555 MW against consumption of 7,493 MW creating net exports of 1,061 MW.
Renewables shape Greek pricing; regional import needs rise; forward markets point to continued pressure
The Greek market reflected renewable penetration with HENEX peakload averaging only €42.70/MWh and prices reaching €0/MWh during the afternoon solar peak . Evening prices remained considerably higher despite low daytime levels.
At the regional level Hungary and Southeast Europe required net imports of 1,753 MW up by 518 MW . Imports into Hungary and Slovenia rose from Austria and Slovakia while exports toward Italy declined.
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