South-East European electricity markets moved sharply higher on Friday as weaker solar generation, rising thermal dispatch and stronger cross-border imports pushed day-ahead prices back above the €120/MWh threshold across most regional exchanges.
Hungary’s HUPX day-ahead market closed at €140.45/MWh, broadly flat day-on-day but retaining its position as one of the highest-priced hubs in Central and Eastern Europe. Romania’s OPCOM climbed further to €144.45/MWh, while Bulgaria’s IBEX rose to €131.75/MWh and Croatia’s CROPEX settled at €130.20/MWh. Serbia’s SEEPEX increased to €122.42/MWh, while Greece’s HENEX remained structurally lower at €122.10/MWh despite recovering from previous low-price sessions.
The market rebound followed a sharp deterioration in the regional supply balance after solar generation across SEE + Hungary dropped by roughly 1.5 GW day-on-day. Total photovoltaic production declined to around 4.5 GW, compared with nearly 6 GW in the previous session, forcing system operators and traders to rely increasingly on imports and flexible thermal generation.
Net regional imports surged to approximately 1,736 MW, up nearly 800 MW from the previous day, while imports from the Central European CORE region into Hungary and SEE exceeded 1.7 GW. At the same time, gas-fired generation increased by around 550 MW, while wind generation expanded by roughly 665 MW, partially offsetting weaker solar conditions.
Market remained highly sensitive to renewable intermittency and evening ramping conditions, particularly as lower daytime solar production coincided with stronger evening demand profiles.
The region is increasingly dependent on flexible balancing resources during these shoulder-season conditions. Once solar weakens, the entire market immediately reverts toward gas, imports and hydro balancing.
The Hungary-Germany spread widened significantly to around €26.6/MWh, compared with just above €4/MWh a day earlier, triggering stronger commercial flows from Austria and Slovakia toward Hungary and the Balkans.
Romania continued showing the strongest intraday volatility profile in the region. OPCOM evening hourly prices exceeded €300/MWh during late peak delivery periods, reflecting tightening balancing conditions and growing dependence on flexible dispatch capacity.
Despite the stronger day-ahead market, renewable penetration across SEE remained elevated. Hydro generation represented around 23 % of the regional power mix, solar and nuclear each accounted for roughly 16 %, while coal contributed approximately 19 % and gas around 14 %.
Gas markets remained relatively stable, with Austrian CEGH front-month contracts trading near €45.9/MWh, while EU carbon allowances held close to €75/t. Coal forwards also remained firm above $110/t, continuing to support thermal dispatch economics across coal-heavy Balkan systems.
Meanwhile, regional energy infrastructure investment momentum continued accelerating. Bulgaria commissioned two major flexibility-related projects this week, including Rezolv Energy’s 225 MW St. George solar plant paired with a 90 MW / 240 MWh battery storage system, alongside Enery’s standalone 150 MW / 601.8 MWh battery installation near Nova Zagora, currently among the largest operational storage facilities in Central and Eastern Europe.
The projects come as European market operators prepare for increasingly volatile pricing conditions linked to renewable oversupply and balancing stress. Under updated SDAC market rules, the harmonized minimum clearing price for European day-ahead markets will fall from -€500/MWh to -€600/MWh from 28 May, following repeated negative pricing events across multiple bidding zones during late April and early May.