Electricity markets across Southeastern Europe opened the new trading week on 25 May 2026 with a strong upward correction, as regional demand recovered sharply after the weekend while renewable generation weakened across several balancing zones. The return of evening scarcity pricing pushed most regional exchanges materially higher, with Serbia emerging 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, reflecting the return of industrial and commercial activity after the weekend slowdown. At the same time, the regional generation mix deteriorated, particularly in hydro and wind output, tightening system balances and increasing reliance on imports from Central Europe.
Hydropower production declined by around 636 MW to 5,982 MW, while wind generation fell by approximately 305 MW to 3,848 MW. Solar output also softened by more than 220 MW, reducing midday oversupply conditions that had recently driven widespread negative pricing events.
Against this backdrop, regional electricity prices rebounded sharply. Serbia’s SEEPEX recorded the highest day-ahead base price in the region at 108.60 EUR/MWh, rising by more than 32 EUR/MWh day-on-day. Slovenia followed at 103.38 EUR/MWh, while Croatia reached 99.59 EUR/MWh, Romania 93.92 EUR/MWh, and Hungary’s HUPX settled at 91.39 EUR/MWh. Greece remained structurally lower at 73.44 EUR/MWh, supported by stronger solar penetration and softer balancing pressure in the southern zone.
The spread structure highlighted growing fragmentation of the SEE electricity market. 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 significant discounts compared with northern SEE markets, reflecting divergent renewable profiles and persistent cross-border transmission bottlenecks.
Hourly curves confirmed that the region remains trapped between midday renewable oversupply and evening scarcity conditions once solar output collapses. Negative prices continued appearing across interconnected markets despite the overall bullish daily average. Hungary recorded lows of -10.5 EUR/MWh, Slovenia dropped to -29.3 EUR/MWh, while Austria briefly plunged to -50.4 EUR/MWh during the solar peak.
However, evening ramp-up pricing returned strongly across the region. Most exchanges recorded daily highs during hour 21 or 22, when thermal generation regained marginality after sunset. Hungary peaked near 178 EUR/MWh, Romania at 178.2 EUR/MWh, Croatia at 179.5 EUR/MWh, while Slovenia briefly reached 180 EUR/MWh, highlighting extreme intraday volatility.
This increasingly volatile structure continues strengthening the investment case for battery energy storage systems (BESS) across Southeastern Europe. The combination of negative midday pricing and extreme evening spreads creates expanding merchant arbitrage opportunities, particularly in Serbia, Romania, Bulgaria and Hungary, where balancing markets remain underdeveloped.
Cross-border flow patterns reinforced tightening regional balances. Greece imported roughly 1,098 MW, while Serbia remained one of the region’s largest importing nodes with approximately 1,365 MW net imports. Romania exported around 826 MW, benefiting from stronger domestic generation availability and favorable interconnection positioning.
Broader structural concerns were echoed in earlier ACER analysis, which identified Southeastern Europe as one of the most vulnerable regions during periods of renewable intermittency and peak evening demand. The assessment highlighted insufficient transmission capacity, limited system flexibility and constrained cross-border integration as key drivers of persistent volatility.
ACER emphasized the need for accelerated grid modernization, including dynamic line rating systems, network-enhancing technologies and expanded storage deployment. These recommendations increasingly align with ongoing investments across Romania, Bulgaria and Slovenia, where battery projects and digital grid upgrades are rapidly expanding alongside renewable capacity growth.
Fuel and carbon markets remained relatively stable despite sharp electricity price movements. Austrian CEGH gas forwards traded near 49.51 EUR/MWh, while EU carbon allowances remained elevated at approximately 76.92 EUR/t. API2 coal contracts held around 126 USD/t for June delivery.
The persistence of high carbon prices continues reshaping generation economics across the Balkans. Coal still represented around 14% of regional generation, but elevated EUA costs are increasingly pressuring lignite-heavy systems as renewable penetration expands and carbon exposure intensifies.
Weather forecasts suggest rising temperatures across SEE markets in the coming days, particularly in Serbia, Romania and Montenegro, where levels could approach 24–26°C by midweek. Rising cooling demand combined with stronger solar output may further intensify the familiar pattern of midday price collapses followed by evening scarcity spikes.
The current structure increasingly resembles mature Western European renewable markets, but without comparable flexibility infrastructure or storage penetration. This imbalance is expected to keep volatility elevated throughout the summer period, especially across Serbia and neighboring SEE markets, where transmission constraints, thermal dependence and renewable intermittency continue interacting within a stressed regional balancing system.