Electricity prices increased across most Southeast European markets in June 2026, with the period 16–30 June rising versus 1–15 June. Hungary’s HUPX reached €149.01/MWh, up €48.7/MWh, while Romania’s OPCOM settled at €146.80/MWh, an increase of €47.6/MWh. Croatia and Slovenia ended the month at €136.67/MWh and €134.33/MWh, respectively. Serbia’s SEEPEX rose to €114.87/MWh and Montenegro’s BELEN averaged €108.63/MWh, while Bulgaria and Greece recorded more moderate gains to €99.72/MWh and €95.72/MWh.
Demand and temperatures tighten supply across HU+SEE
The main driver was higher electricity demand linked to rising temperatures. Average consumption across the HU+SEE region increased from 28,054 MW in the first half of June to 31,414 MW in the second half, a rise of 3,360 MW. Temperatures across HU+SEE excluding Greece climbed from 20.3°C to 25.5°C, while Greece warmed from 24.1°C to 26.7°C.
As temperatures increased, the market moved from a renewable-friendly shoulder season into an early-summer period with tighter supply conditions. By late June, the region shifted from occasional export surpluses into import dependency. HU+SEE averaged -466 MW in net exports during the second half of June before falling to -2,682 MW on 30 June.
Generation output rises but evening flexibility becomes decisive
Generation expanded across nearly all technologies during the month, but it did not fully offset the demand increase. Gas-fired generation rose by 1,177 MW to 4,757 MW, coal output increased by 476 MW to 5,014 MW, and nuclear generation climbed by 922 MW to 4,901 MW. Wind and solar production increased by 841 MW and 894 MW respectively.
Hydropower was the only major source to decline slightly, dropping by 130 MW to 6,098 MW. Even so, renewables remained a large share of the regional mix: solar at 23%, hydro at 20%, coal at 17%, gas at 16%, nuclear at 16%, and wind at 8%. Pricing increasingly reflected flexible capacity availability during evening hours rather than average renewable output.
Midday prices soften while hourly peaks rise
Dispatchability and flexibility became more prominent as strong solar output pushed midday electricity prices close to zero or into negative territory in several markets. Evening price spikes became more pronounced across the region. During the reporting period, Hungary recorded a maximum hourly price of €923.1/MWh.
Other maximum hourly prices included Romania at €954.6/MWh, Slovenia at €1,041.5/MWh, Croatia at €946.6/MWh, and Serbia at €800/MWh . These movements indicated that storage capability, ramping capacity, interconnector availability and flexible generation played a larger role in setting prices than total energy output alone.
Fuel costs ease while carbon prices rise
Lower fuel costs did not prevent higher electricity prices during late June. Average CEGH natural gas prices fell from €49.35/MWh to €43.06/MWh over the period cited in the report. Greek gas prices declined from €46.14/MWh to €41.37/MWh.
At the same time, EU carbon allowance (EUA) prices increased from €77.85/t to €80.31/t . The report attributed the second-half June price rally primarily to weather conditions, nuclear operating constraints, import dependence and evening residual-load scarcity rather than changes in fuel costs.
Hungary faces cooling constraints at Paks as HUPX leads premiums
Hungary emerged as a key stress point within the regional market as demand reached a new summer peak of 7,488 MW on 29 June . The Paks Nuclear Power Plant faced temporary operating restrictions after Danube cooling-water temperatures exceeded environmental thresholds.
Authorities granted a temporary exemption limiting the reduction in nuclear output to 40 MW instead of a potential 640 MW. Despite this measure, exceptional heat combined with high demand, nuclear cooling challenges and import requirements supported HUPX as the premium pricing benchmark across Southeast Europe.
Romania’s solar record coexists with net imports; Greece exports northward
In Romania, dispatchable solar generation set a record of 2,952 MW. The figure was combined with approximately 1,930 MW of prosumer capacity that pushed total midday solar output close to 5 GW. Even with this level of midday generation, Romania averaged -637 MW in net imports during the second half of June.
The report linked these figures to widening gaps between midday renewable availability and evening supply shortages . In Greece, wholesale electricity pricing averaged €95.72/MWh while net exports averaged 1,385 MW. With a generation mix of 36% gas, 33% solar, and 22% wind, Greece exported surplus renewable energy and flexible gas-fired generation northward into Bulgaria, North Macedonia and Albania while maintaining system stability.
Serbia’s trading volume rises; Montenegro remains an importer amid outages
Serbia’s market showed both price increases and higher activity levels during June. SEEPEX averaged €114.87/MWh while day-ahead trading volume reached a record monthly total of 569,139 MWh, up 12.6% year-on-year . Serbia remained structurally import-dependent with net exports averaging -706 MW.
The generation mix continued to be dominated by coal at 66% and hydropower at 32%. The report said these fundamentals support investment including Serbia’s planned 1 GW solar program, battery storage of at least 200 MW / 400 MWh, financing discussions for the Bistrica pumped-storage project and new wind developments including Alibunar .
In Montenegro, BELEN averaged €108.63/MWh while net imports averaged -77 MW . State utility EPCG spent approximately €142 million on electricity imports during 2025 due to an outage at TPP Pljevlja and weak hydrological conditions.
Around 780 GWh of imported electricity replaced lost thermal generation while another 320 GWh compensated for lower hydropower production . Planned transmission upgrades by CGES at Perucica and Pljevlja could enable approximately 550 MW of new renewable energy connections; improvements along the Trebinje–Perucica–Podgorica–Vau i Dejes corridor could increase cross-border transfer capacity to around 600 MW.
Batteries and grid projects expand across Bulgaria, Hungary and Romania
The report described an investment landscape across Southeast Europe shifting toward battery storage, grid modernization and hybrid renewable projects . Bulgaria expanded its storage portfolio with several new battery projects including Solarpro’s 602 MWh Burgas facility. Hungary commissioned new storage systems in Tiszaujvaros and Ajka.
Romania continued developing a pipeline including solar-plus-storage facilities, standalone batteries, hybrid PPAs and major transmission investments . The report said these technologies are positioned to capture widening intraday price spreads by storing midday solar generation and supplying electricity during expensive evening peak periods.
Southeast Europe pricing increasingly reflects interconnector access and flexible capacity
The report said Southeast Europe is moving toward a pricing regime where solar influences daytime prices while gas-fired generation and imports shape evening price peaks . Interconnector availability was described as influencing local scarcity premiums as flexible capacity becomes more relevant for hourly outcomes.
The month’s data were presented as showing that rapid renewable expansion alone did not reduce market volatility . The report also stated that without sufficient storage capacity alongside stronger grids and greater system flexibility—renewable growth can amplify intraday price swings . It further pointed to long-term opportunities concentrated in hybrid solar-storage projects, wind paired with balancing solutions, pumped-storage facilities, grid-scale batteries and industrial power purchase agreements featuring hourly matching and flexibility mechanisms .
