Day-ahead electricity prices across Southeast Europe rose sharply on 28 May, but trading no longer reflected a single synchronized regional block. Central European-linked hubs increased on tightening import availability and falling wind generation. Greece, Bulgaria and Albania remained weaker as solar positioning improved and balancing pressure eased.
In Hungary, HUPX settled at €118.22/MWh, up €3.5/MWh day-on-day. Slovenia’s BSP closed at €116.29/MWh and Croatia’s CROPEX at €116.19/MWh. Serbia’s SEEPEX fell to €109.42/MWh, down €7.7/MWh, while Greece’s HENEX dropped to €89.64/MWh and Bulgaria’s IBEX to €94.67/MWh.
Italy stayed the premium market at €131.30/MWh. The pricing spread supported southbound economics for exporters and traders. Across the region, the relative moves differed between Central European-linked hubs and southeastern markets.
Wind collapse and softer solar drive thermal rebalancing
The main structural factor was a collapse in regional wind output. Forecast wind generation fell by roughly 1,240 MW day-on-day to 1,953 MW. Solar generation also eased by around 200 MW, contributing to system rebalancing through thermal units and imports.
Coal generation increased by 358 MW. Gas-fired output rose another 260 MW, aligning with renewed thermal marginality across the region. These shifts coincided with higher day-ahead prices in multiple hubs despite weaker renewable supply.
Imports tighten even as renewables underperform
Despite lower renewable generation, total regional imports decreased sharply. Net imports fell to 526 MW, down more than 1,000 MW day-on-day. CORE imports from Austria and Slovakia declined by 1,460 MW.
This tightening in import availability corresponded with stronger gains in Central European-linked hubs compared with southeastern markets. Hungary’s spread versus Germany moved to -€4.10/MWh, narrowing from the previous day’s deep discount. The move reflected reduced cheap German renewable overflow into Hungary and the wider SEE region.
Intraday price swings intensify around evening ramps
Intraday profiles showed continued midday price declines driven by solar conditions, alongside more pronounced evening price increases. HUPX peaked near €350/MWh during evening hour H21. Slovenia’s BSP briefly approached €394/MWh.
The pattern indicated that liquidity and flexibility tightened quickly once solar output faded and wind underperformed. The resulting volatility fed through into how market participants value timing of generation and system balancing capability.
Batteries and hybrid projects expand across SEE
The market moves continued to affect battery storage economics across Southeast Europe. Trading increasingly monetized evening flexibility rather than baseload generation alone. The spread between midday lows and evening peaks remained supportive for battery-backed solar portfolios, particularly in Bulgaria, Romania, Slovenia and Croatia where storage pipelines were accelerating.
Bulgaria provided a key example of hybrid buildout dynamics. The newly commissioned 242 MW Tenevo solar plant entered full operation alongside the first phase of a major battery system. When completed, the storage component is expected to reach 311 MW / 772.5 MWh.
Romania’s integration plan also combined solar with storage through hydropower-solar-storage development. Hidroelectrica announced plans for 90 MW of floating solar on Lower Olt reservoirs paired with 200 MW / 800 MWh of battery storage.
Serbia introduces active buyer framework for transmission-connected solar
Serbia’s market structure is shifting beyond conventional utility demand under a new “active buyer” framework handled by EMS. HBIS Serbia and Linglong submitted the first applications for large self-generation solar projects connected directly to the transmission system.
HBIS Serbia plans a 63 MW solar plant at Smederevo, while Linglong targets 39.9 MW in Zrenjanin. The change affects regional power markets because industrial buyers are taking roles that span consumption, production, storage operation and potential trading activity.
Gas, carbon and hydrology remain supporting factors for dispatch economics
Austrian CEGH front-month gas traded near €47.48/MWh. EUA carbon allowances stayed elevated around €78.72/tCO₂. Carbon pricing continued supporting gas-over-coal economics in several markets even as coal temporarily returned to dispatch due to weaker renewable output.
Danube flows near 6,636 m³/s continued supporting regional hydro generation, although hydro output remained broadly flat day-on-day. Commercial flow patterns also 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.