Day-ahead electricity markets across Southeast Europe moved higher on 28 May, but trading no longer reflected a single synchronized regional block. Central European-linked hubs strengthened on tightening import availability and a collapse in wind generation. Greece, Bulgaria and Albania were comparatively weaker amid stronger solar positioning and softer balancing conditions.
Spot price moves in key hubs
Hungary’s HUPX closed at €118.22/MWh, up €3.5/MWh day-on-day. Slovenia BSP rose to €116.29/MWh, while Croatia CROPEX settled at €116.19/MWh. Serbia SEEPEX fell to €109.42/MWh, down €7.7/MWh.
Greece HENEX dropped to €89.64/MWh, and Bulgaria IBEX closed at €94.67/MWh. Italy remained the premium market at €131.30/MWh. The southbound spread economics for exporters and traders stayed supported by the Italian price level.
Wind collapse shifts dispatch and imports
The main structural driver was a sharp decline in regional wind production. Forecast wind output fell by roughly 1,240 MW day-on-day to 1,953 MW. Solar generation also eased by around 200 MW, requiring thermal generation and imports to rebalance.
Coal output increased by 358 MW, while gas-fired generation rose another 260 MW. Despite weaker renewable output, total regional imports declined sharply. Net imports fell to only 526 MW, down more than 1,000 MW day-on-day.
CORE imports from Austria and Slovakia collapsed by 1,460 MW. This tightening of import availability aligned with stronger gains in Central European-linked hubs compared with southeastern markets.
Central European spreads tighten; intraday ramps intensify
Hungary’s spread versus Germany moved to -€4.10/MWh, narrowing materially from the previous day’s deep discount. The compression was linked to reduced cheap German renewable overflow into Hungary and the broader SEE region.
Intraday pricing still showed solar-driven midday declines across the region, but evening ramps became more pronounced. HUPX peaked near €350/MWh during evening hour H21, while Slovenia BSP briefly approached €394/MWh. Liquidity and flexibility tightened quickly once solar output faded and wind underperformed.
Batteries, hybrid projects and new market participation in Serbia
The shift in price shape is affecting battery storage economics across SEE. Markets increasingly monetize evening flexibility rather than baseload generation alone, with the midday-to-evening spread supporting battery-backed solar portfolios in Bulgaria, Romania, Slovenia and Croatia where storage pipelines are accelerating rapidly.
Bulgaria provided a key example of hybridization through renewables-plus-storage commissioning. The newly commissioned 242 MW Tenevo solar plant entered full operation alongside the first phase of a major battery system, with expected storage capacity of 311 MW / 772.5 MWh.
Romania is also progressing toward hydro-solar-storage integration via Hidroelectrica plans for floating solar on Lower Olt reservoirs totaling 90 MW, paired with 200 MW / 800 MWh of battery storage.
In Serbia, EMS received the first applications under a new “active buyer” framework from HBIS Serbia and Linglong for large self-generation solar projects connected directly to the transmission system. HBIS plans a 63 MW solar plant at Smederevo, while Linglong targets 39.9 MW in Zrenjanin.
Gas stability, hydrology support and commercial flows into SEE
Austrian CEGH front-month gas traded near €47.48/MWh, while EUA carbon allowances stayed elevated around €78.72/tCO₂. Carbon pricing therefore continued supporting gas-over-coal economics in several markets even as coal temporarily returned to dispatch due to weaker renewable output.
Hydrology remained supportive as Danube flows were near 6,636 m³/s. Regional hydro output was broadly flat day-on-day despite the sustained flow level.
Commercial flow patterns showed Greece acting as a major regional balancing sink, while Hungary maintained its role as the dominant Central European transit node into SEE markets. Serbia remained structurally import-linked to Hungary and Bosnia during higher-priced evening periods, even as SEEPEX prices softened overall relative to neighboring hubs.
