Electricity markets across Southeastern Europe opened the week on 25 May 2026 with a strong upward correction. Regional demand recovered after the weekend slowdown, while renewable generation weakened across several balancing zones. Evening scarcity pricing returned, lifting most exchanges materially higher. Serbia emerged as the highest-priced market in the wider SEE region.
Regional consumption increased by more than 2 GW day-on-day to approximately 25,836 MW. The generation mix deteriorated, particularly in hydro and wind output, tightening system balances. Imports from Central Europe increased as a result. The shift in availability coincided with the price rebound across the region.
Hydro, wind and solar output changes drive tighter balances
Hydropower production fell by around 636 MW to 5,982 MW. Wind generation declined by approximately 305 MW to 3,848 MW. Solar output also softened by more than 220 MW, reducing midday oversupply conditions that had recently contributed to negative pricing events. The combined change in generation availability tightened balancing requirements.
Day-ahead price levels show Serbia leading the region
Regional electricity prices rebounded sharply following the weekend recovery in demand. Serbia’s SEEPEX recorded the highest day-ahead base price at 108.60 EUR/MWh, up by more than 32 EUR/MWh day-on-day. Slovenia followed at 103.38 EUR/MWh, while Croatia reached 99.59 EUR/MWh. Romania was at 93.92 EUR/MWh, and Hungary’s HUPX settled at 91.39 EUR/MWh.
Greece remained structurally lower at 73.44 EUR/MWh. The lower level was supported by stronger solar penetration and softer balancing pressure in the southern zone. Price differentials also reflected market fragmentation across SEE. Greece, Montenegro and North Macedonia traded at significant discounts versus northern SEE markets.
Negative midday pricing and evening scarcity return in hourly curves
Hourly curves showed the region moving between midday renewable oversupply and evening scarcity conditions when solar output collapses. Negative prices continued appearing across interconnected markets despite higher overall daily averages. Hungary recorded lows of -10.5 EUR/MWh, while Slovenia dropped to -29.3 EUR/MWh. Austria briefly plunged to -50.4 EUR/MWh during the solar peak.
Evening ramp-up pricing returned strongly across the region, with many exchanges setting daily highs during hour 21 or 22 after sunset. Thermal generation regained marginality during these hours. Hungary peaked near 178 EUR/MWh, Romania at 178.2 EUR/MWh, and Croatia at 179.5 EUR/MWh. Slovenia briefly reached 180 EUR/MWh, indicating extreme intraday volatility.
Bilateral spreads widen alongside cross-border flows and carbon costs
The spread structure pointed to growing fragmentation within SEE electricity markets. Serbia traded more than 17 EUR/MWh above Hungary, while Slovenia maintained a premium of nearly 12 EUR/MWh over HUPX. Greece, Montenegro and North Macedonia continued trading at discounts linked to divergent renewable profiles and cross-border transmission bottlenecks.
Cross-border flows show Greece importing and Serbia net imports rising
Cross-border flow patterns reinforced tightening regional balances. Greece imported roughly 1,098 MW, while Serbia remained one of the largest importing nodes with approximately 1,365 MW net imports. Romania exported around 826 MW, supported by stronger domestic generation availability and favorable interconnection positioning.
ACER highlights transmission limits and flexibility constraints in SEE volatility dynamics
An earlier ACER assessment identified Southeastern Europe as among the most vulnerable regions during renewable intermittency and peak evening demand periods. It cited insufficient transmission capacity, limited system flexibility and constrained cross-border integration as drivers of persistent volatility.
The regulator emphasized accelerated grid modernization, including dynamic line rating systems, network-enhancing technologies and expanded storage deployment. These recommendations align with ongoing investments across Romania, Bulgaria and Slovenia involving battery projects and digital grid upgrades alongside renewable capacity growth.
Gas forwards, coal contracts and EU ETS move independently of power price swings
Fuel and carbon markets remained relatively stable despite sharp electricity price movements. Austrian CEGH gas forwards traded near 49.51 EUR/MWh. EU carbon allowances stayed elevated at approximately 76.92 EUR/t, while API2 coal contracts held around 126 USD/t for June delivery.
The persistence of high carbon prices continues affecting generation economics across the Balkans. Coal represented around 14% of regional generation, with elevated EUA costs increasingly pressuring lignite-heavy systems as renewable penetration expands and carbon exposure intensifies.
Forecast temperatures point to potential cooling demand changes across SEE markets
Weather forecasts indicate rising temperatures across SEE markets in the coming days, particularly in Serbia, Romania and Montenegro, where levels could approach 24–26°C by midweek. Higher cooling demand combined with stronger solar output may intensify midday price collapses followed by evening scarcity spikes.
The current market structure resembles mature Western European renewable patterns but without comparable flexibility infrastructure or storage penetration. Volatility is expected to remain elevated through summer across Serbia and neighboring SEE markets as transmission constraints, thermal dependence and renewable intermittency interact within a stressed regional balancing system.
