During the second half of May, the Southeast European electricity market moved decisively lower. Stronger hydro conditions, faster solar generation and improved wind output outweighed the upward pressure from higher gas and carbon prices. The market increasingly behaved like a renewable-driven system, widening price differences between flexible assets and inflexible generation.
Average regional demand excluding Greece eased from 22,578 MW in the first half of May to 21,927 MW in the second half despite warmer weather. Hydro generation increased to 6,580 MW, solar output reached 5,632 MW, and wind generation climbed to 2,833 MW. Coal and nuclear generation both declined as renewable technologies supplied the majority of electricity.
The price impact was visible across every major power exchange. Albania recorded the largest correction in the region, with ALPEX falling from €98.60/MWh to €81.16/MWh, down more than 17%. Strong hydrology supported lower-cost generation and reinforced Albania’s export position during wet periods.
Price declines across Balkan exchanges
Montenegro followed a similar pattern as BELEN prices dropped from €98.76/MWh to €83.92/MWh. The move placed Montenegro among the cheapest markets in Southeast Europe. North Macedonia also saw downward pressure, with MEMO prices declining from €97.17/MWh to €82.66/MWh.
The regional decline was less severe but still significant in larger markets. Serbia’s SEEPEX averaged €91.95/MWh, down from €101.61/MWh, a fall of almost 10%. Bulgaria’s IBEX decreased from €104.98/MWh to €97.41/MWh, while Romania’s OPCOM moved from €115.88/MWh to €103.64/MWh.
Despite the correction, Romania remained among the highest-priced markets in Southeast Europe. Transmission constraints and Romania’s role as a regional balancing hub were cited as key factors behind that relative pricing level.
Greece, Croatia and Slovenia see different levels of correction
Greece continued moving lower as renewable penetration increased. HENEX prices averaged €85.81/MWh, down from €92.36/MWh. The decline reinforced concerns among solar investors about declining merchant revenues and more frequent negative-price periods.
Croatia and Slovenia were comparatively resilient during May. CROPEX averaged €101.52/MWh, while Slovenia’s BSP averaged €101.15/MWh. The two markets remained more closely coupled with Central European pricing, contributing to smaller corrections than those seen in southern Balkan exchanges.
Daylight-evening spread widens as solar output rises
The most notable structural change during May was not only the fall in average prices but also the expansion of the price gap between daylight and evening hours. Solar generation continued suppressing midday prices across the region as photovoltaic output increased and displaced thermal units during daylight hours.
After solar production faded in the evening, gas, hydro and flexible thermal units regained importance, supporting higher prices during peak consumption periods. Battery storage, pumped hydro, flexible gas generation and dispatchable hydro facilities gained relative value during May as a result of that time-shifting effect.
Cross-border flows shift toward Italy; commodity prices rise
Regional cross-border flows changed over the month, with net exports improving in the second half of May. Southeast Europe exported more electricity toward Italy while reducing dependence on imports from Central Europe. Flows toward Italy shifted from net imports in the first half to net exports in the second half.
Commercial flow patterns also highlighted Romania’s role as a major exporter toward Hungary. Bulgaria maintained its position as a key balancing corridor linking Romania, Greece, Serbia and Turkey, while Serbia continued operating as a transit and trading hub at the intersection of flows from Romania, Bulgaria, Bosnia and Herzegovina and Hungary.
Commodity markets moved in the opposite direction to power prices during May. Average Austrian gas prices increased to €49.85/MWh, Greek gas prices rose to €46.09/MWh, and EU carbon allowances climbed to €77.18/t. Despite those increases under traditional conditions, electricity prices declined sharply.
Renewables expansion and hydrology shape market outcomes into summer
The expansion of solar generation capacity continued across Romania, Bulgaria, Greece and increasingly parts of the Western Balkans. Standalone merchant solar projects faced growing revenue compression during daylight hours as solar output increased. Wind projects were described as better positioned because their production profiles align more closely with evening and nighttime demand peaks when prices remain stronger.
Hydropower remained central to regional price formation during May as improved hydrology strengthened export capability across Albania, Montenegro and parts of Bosnia and Herzegovina while reducing regional price levels. Weather conditions were identified as an important variable for traders heading into summer.
A three-zone pricing pattern emerges across Southeast Europe
The market increasingly separated into three distinct zones based on pricing behavior described for May 2026. The renewable-discount zone comprised Albania, Montenegro and North Macedonia, with Greece included increasingly due to abundant hydro and solar output suppressing prices.
A balancing and transit zone was led by Serbia, Bulgaria and Romania, where network constraints and regional trading activity maintained higher price levels. A Central European convergence zone was represented by Croatia, Slovenia and Hungary, where stronger integration with western European markets provided greater price support.