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 area, while Greece and Bulgaria saw lower levels supported by strong renewable output.
Spot price jumps across central and western 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 all neighbouring markets except Albania. Croatia climbed by €23.3/MWh to €138.73/MWh, while Romania increased by €22.1/MWh to €132.87/MWh.
Slovenia gained €16.4/MWh to €141.83/MWh, and Montenegro advanced by €15.7/MWh to €140.79/MWh. Hungary’s HUPX benchmark moved up by €10.3/MWh to €132.34/MWh, staying close to Germany where the day-ahead price reached €126.84/MWh.
The Hungarian premium over Germany was limited to €5.50/MWh, despite higher stress in the forward market and significant hourly volatility during the evening ramp. In contrast, Greece and Bulgaria posted lower prices on the back of renewable generation.
Renewables weigh on Greece and Bulgaria; Albania remains highest
Greece declined by €11.2/MWh to €95.79/MWh, while Bulgaria fell by €4.4/MWh to €102.59/MWh. Greece traded €36.55/MWh below Hungary and almost €50/MWh below Serbia, reflecting high solar and wind availability.
Albania remained the most expensive market in the region at 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 continued as the regional premium market at €177.13/MWh.
Nuclear availability falls along the Danube as demand rises
The price surge was linked to deteriorating nuclear availability along the Danube corridor. Hungary’s Paks plant reduced output from unit 1 by around 254 MW due to exceptionally low river levels affecting cooling conditions.
Nuclearelectrica placed Cernavoda unit 1 into a controlled shutdown at the same time, cutting combined regional nuclear output by 542 MW from 5,560 MW to 5,018 MW. Hungarian nuclear production fell from 1,834 MW to 1,577 MW, while Romanian output declined from 1,165 MW to 880 MW.
The full effect of the Romanian outage was expected to show up more clearly in Wednesday’s physical balance because the shutdown began during Tuesday. With the Danube flow indicator at approximately 4,691 cubic metres per second, river conditions remained an operational risk for both Paks and Cernavoda.
Demand forecast increases; solar and wind support midday prices only partially
The nuclear reduction coincided with higher regional electricity demand forecast at 32,490 MW, up 1,417 MW versus Tuesday. Forecasts for consumption increased in Hungary, Greece, Romania, Bulgaria, Slovenia, and Croatia, as temperatures rose and cooling demand increased.
Regional solar production was expected to reach 7,417 MW and wind generation to increase to 2,455 MW. Renewables helped create deep midday price declines but did not remove the evening scarcity period after solar output faded.
Day-night spreads widen: peak scarcity concentrates in evening hours
The imbalance drove a sharp difference between daytime and evening prices across multiple markets. 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 sharply 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, with BSP reaching €305.10/MWh at hour 20 and CROPEX peaking at €289.90/MWh. The hourly profile indicated that stress concentrated during the sunset ramp rather than throughout the full day.
Tight structures in Serbia and Croatia; Montenegro exports via Italy interconnector
Serbia also showed tight pricing throughout Wednesday’s session on SEEPEX, staying above €45.00/MWh before rising to €251.10/MWh at hour 21.
Serbian peakload averaged €112.90/MWh while off-peak prices reached €178.00/MWh.
The relatively high midday floor reflected limited solar penetration alongside a tighter domestic balance and continued reliance on imports.
Serbia’s consumption was forecast at 3,457 MW against 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 SEEPEX premium over HUPX was therefore linked to competition for regional supply as Romanian nuclear availability fell and Croatian import demand rose.
Cross-border capacity availability became a key factor shaping Serbian pricing.
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.
CROPEX followed HUPX but showed stronger evening price pressure.
Montenegro 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.
The Italian market maintained a premium of more than €36/MWh over Montenegro.
Cernavoda outage shifts Romania toward imports; Bulgaria stays surplus; Greece exports on renewables
Romania recorded the largest market-position reversal 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 alongside Romania’s slight premium over HUPX.
The Cernavoda outage moved Romania from a regional balancing role into a market requiring additional external support.
Bulgaria remained the region’s main surplus market with production around 5,047 MW compared with consumption of 3,915 MW.
It exported about 1,266 MW to Romania plus 294 MW to North Macedonia and 101 MW to Serbia while importing 517 MW from Greece.
Stable nuclear output at Kozloduy together with strong solar availability supported Bulgaria’s lower price level.
HENEX shows low afternoon prices; regional net imports rise; forward contracts firm up
Greece generated approximately 8,555 MW against consumption of 7,493 MW for net exports of 1,061 MW.
It supplied Bulgaria, North Macedonia and Albania after reversing its position earlier in the week when it had been a net importer.
HENEX peakload averaged only €42.70/MWh with 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 from Austria and Slovakia rose while exports toward Italy declined.
The region relied more heavily on Central European supply despite continued Italian demand.
Hungary’s net imports increased to 1,162 MW.
The country received electricity from Slovakia, Romania and Slovenia while exporting some power to Croatia.
Its balance differed by time period with relatively stable daytime conditions but heavy dependence on neighbouring markets during evening and overnight hours.
Tightness expected into coming days; fuel markets not cited as driver for spot move
The forward curve indicated traders expected continued pressure after Wednesday’s spot delivery.
Hungary Week 32 rose to €203.00/MWh increasing its premium over Germany to €78/MWh.
The contract gained 37.6% since 20 July amid concerns over heat conditions plus nuclear availability and regional import capacity.
The Hungarian August contract increased to €159.50/MWh while Germany Week 32 eased to €125/MWh and Italy Week 32 remained at €174/MWh.
The difference between Hungary Week 32 and Week 33 reflected pricing of the strongest scarcity risk in the immediate period.
Fuel markets were not described as driving factors for the electricity increase: gas prices declined, EU carbon allowances weakened slightly and coal markets stayed broadly stable.
The rally was attributed mainly to physical availability constraints alongside weather conditions and cross-border capacity limitations rather than higher fuel costs.
Main trading risk concentrated between 19:00 and 22:00
The main trading risk remained concentrated during evening hours from 19:00 to 22:00, when solar generation falls but cooling demand stays elevated alongside reduced nuclear output.
Greece and Bulgaria were cited as continuing sources of regional support while Serbia, Croatia and Romania were identified as most exposed to further supply constraints.
With Hungarian forward prices already above €200/MWh, tight conditions were indicated as likely extending beyond Wednesday’s spot delivery.