SEE power prices snap back on evening scarcity as Serbia tops the region

Electricity markets across Southeastern Europe started the new trading week on 25 May 2026 with a pronounced upward correction, driven by a return of evening scarcity pricing. The rebound matters for investors because it underscores how quickly regional price formation is swinging between midday renewable oversupply and post-sunset tightness—an environment that is increasingly shaping capital allocation toward flexibility.

Demand rises while hydro and wind weaken

Regional consumption increased by more than 2 GW day-on-day to about 25,836 MW, reflecting the return of industrial and commercial activity after the weekend slowdown. At the same time, the generation mix deteriorated: hydropower output fell by around 636 MW to 5,982 MW, wind generation declined by approximately 305 MW to 3,848 MW, and solar output softened by more than 220 MW. The reduction in solar generation eased some of the midday oversupply conditions that had recently contributed to negative pricing across interconnected markets.

Serbia records the region’s highest day-ahead price

Against that backdrop, regional electricity prices rebounded sharply. Serbia’s SEEPEX posted the highest day-ahead base price in the wider SEE region at 108.60 EUR/MWh, up by more than 32 EUR/MWh from the previous day. Slovenia followed at 103.38 EUR/MWh and Croatia at 99.59 EUR/MWh; Romania reached 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.

Volatility persists: negative midday prices alongside extreme evening spreads

The spread structure highlighted ongoing fragmentation within Southeastern Europe’s power market. Serbia traded more than 17 EUR/MWh above Hungary, while Slovenia held a premium of nearly 12 EUR/MWh over HUPX. Greece, Montenegro and North Macedonia continued to trade at significant discounts versus northern SEE markets, reflecting differences in renewable profiles and persistent cross-border transmission bottlenecks.

Hourly curves showed a continued pattern of midday renewable oversupply followed by evening scarcity once solar output collapses. Negative prices still appeared despite higher daily averages: Hungary recorded lows of -10.5 EUR/MWh, Slovenia fell to -29.3 EUR/MWh, and Austria briefly plunged to -50.4 EUR/MWh during the solar peak.

Evening ramp-up pricing returned strongly across the region as thermal generation regained marginality after sunset. Most exchanges set daily highs during hour 21 or 22: Hungary peaked near 178 EUR/MWh, Romania at 178.2 EUR/MWh, Croatia at 179.5 EUR/MWh, while Slovenia briefly reached around 180 EUR/MWh—levels that point to extreme intraday volatility.

BESS investment case strengthens as arbitrage opportunities expand

This increasingly volatile structure is strengthening the investment case for battery energy storage systems (BESS) across Southeastern Europe. The combination of negative midday pricing and very large evening spreads creates expanding merchant arbitrage opportunities—particularly in Serbia, Romania, Bulgaria and Hungary—where balancing markets remain underdeveloped.

Cross-border flows tighten balances

Cross-border flow patterns also reflected tighter 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 flags grid constraints and calls for faster modernization

The day’s price behavior aligns with earlier concerns raised in ACER analysis identifying Southeastern Europe as among the most vulnerable regions during periods of renewable intermittency and peak evening demand. ACER pointed to insufficient transmission capacity, limited system flexibility and constrained cross-border integration as key drivers behind persistent volatility.

The regulator emphasized accelerated grid modernization—including dynamic line rating systems, network-enhancing technologies and expanded storage deployment—and noted that these recommendations are increasingly consistent with investments underway in Romania, Bulgaria and Slovenia as battery projects and digital grid upgrades expand alongside renewable growth.

Fuel and carbon markets steady as weather may intensify swings

Fuel and carbon markets were relatively stable despite sharp electricity price moves: Austrian CEGH gas forwards traded near 49.51 EUR/MWh; EU carbon allowances were around 76.92 EUR/t; and API2 coal contracts were about 126 USD/t for June delivery.

EUA costs continue to reshape generation economics across the Balkans. Coal still accounted for roughly 14% of regional generation, but elevated carbon exposure is increasingly pressuring lignite-heavy systems as renewable penetration rises.

Weather forecasts indicate rising temperatures across SEE markets over coming days—especially in Serbia, Romania and Montenegro—where levels could approach 24–26°C by midweek. Higher cooling demand alongside stronger solar output may further intensify the familiar cycle of midday price collapses followed by evening scarcity spikes.

Taken together, today’s pricing structure increasingly resembles mature Western European renewable markets—yet without comparable flexibility infrastructure or storage penetration—meaning volatility is likely to remain elevated through summer across Serbia and neighboring SEE markets where transmission constraints, thermal dependence and renewable intermittency continue interacting within a stressed balancing system.