The electricity markets in Southeastern Europe (SEE) saw a notable rebound on 25 May 2026, driven by a sharp increase in regional demand following the weekend. This uptick coincided with a decline in renewable energy generation across several balancing zones, leading to heightened evening scarcity pricing. Serbia emerged as the highest-priced market in the region, reflecting the overall upward trend.
Regional electricity consumption surged by over 2 GW from the previous day, reaching approximately 25,836 MW. This increase is indicative of a resurgence in industrial and commercial activities after a weekend lull. However, the generation mix faced challenges, particularly with reduced hydro and wind outputs, which tightened system balances and increased dependency on imports from Central Europe.
Specifically, hydropower production fell by around 636 MW to 5,982 MW, while wind generation decreased by approximately 305 MW to 3,848 MW. Additionally, solar output diminished by more than 220 MW, alleviating some of the midday oversupply that had previously resulted in negative pricing events across the region.
In this context, regional electricity prices rebounded significantly. Serbia’s SEEPEX reported a day-ahead base price of 108.60 EUR/MWh, marking an increase of over 32 EUR/MWh from the previous day. Slovenia followed closely with a price of 103.38 EUR/MWh, while Croatia recorded 99.59 EUR/MWh. Romania’s price stood at 93.92 EUR/MWh, and Hungary’s HUPX settled at 91.39 EUR/MWh. Greece maintained a lower price at 73.44 EUR/MWh due to stronger solar contributions and reduced balancing pressures.
The pricing dynamics highlighted an increasing fragmentation within the SEE electricity market. Serbia traded more than 17 EUR/MWh above Hungary, and Slovenia maintained a nearly 12 EUR/MWh premium over HUPX. In contrast, Greece, Montenegro, and North Macedonia continued to trade at significant discounts compared to their northern counterparts, reflecting differences in renewable profiles and ongoing cross-border transmission constraints.
Hourly data revealed that the region remains caught between periods of midday renewable oversupply and evening scarcity when solar generation diminishes. Negative pricing persisted in interconnected markets despite an overall bullish daily average; Hungary experienced lows of -10.5 EUR/MWh, Slovenia dropped to -29.3 EUR/MWh, and Austria briefly fell to -50.4 EUR/MWh during peak solar hours.
Evening ramp-up pricing returned robustly across the region as thermal generation regained its marginal status post-sunset. Most exchanges peaked during hours 21 or 22; Hungary reached around 178 EUR/MWh, Romania hit 178.2 EUR/MWh, Croatia peaked at 179.5 EUR/MWh, and Slovenia briefly touched 180 EUR/MWh—illustrating significant intraday volatility.
This volatility underscores the growing relevance of battery energy storage systems (BESS) across Southeastern Europe. The combination of negative midday pricing and extreme evening spreads has created expanding merchant arbitrage opportunities in countries such as Serbia, Romania, Bulgaria, and Hungary where balancing markets remain underdeveloped.
Cross-border flow patterns further emphasized tightening regional balances; Greece imported approximately 1,098 MW while Serbia was one of the largest importing nodes with net imports around 1,365 MW. Romania exported about 826 MW due to favorable domestic generation availability and advantageous interconnection positioning.
Broader structural concerns were highlighted by recent ACER analyses which identified Southeastern Europe as particularly vulnerable during periods of renewable intermittency and peak evening demand. Key issues include insufficient transmission capacity, limited system flexibility, and constrained cross-border integration—all contributing to persistent market volatility.
ACER has called for accelerated grid modernization efforts that encompass dynamic line rating systems and enhanced storage deployment. These recommendations align with ongoing investments in Romania, Bulgaria, and Slovenia where battery projects and digital grid upgrades are advancing alongside renewable capacity growth.
Despite fluctuations in electricity prices, fuel and carbon markets exhibited relative stability. 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 hovered around 126 USD/t for June delivery.
The sustained high carbon prices are reshaping generation economics throughout the Balkans; coal accounted for roughly 14% of regional generation but is increasingly pressured by elevated EUA costs as renewable penetration rises alongside intensified carbon exposure.
Weather forecasts indicate rising temperatures across SEE markets in the coming days—particularly in Serbia, Romania, and Montenegro—where temperatures may approach 24–26°C midweek. This increase in cooling demand combined with stronger solar output could further exacerbate the familiar pattern of midday price collapses followed by evening scarcity spikes.
The current market structure increasingly mirrors mature Western European renewable markets but lacks comparable flexibility infrastructure or storage capabilities. This imbalance is likely to maintain elevated volatility throughout the summer months across Serbia and neighboring SEE markets where transmission constraints interact with thermal dependence and renewable intermittency within a stressed regional balancing system.
