Calendar week 22 of 2026 saw a continued shift in the Southeast European power system toward solar-led price formation. Average prices declined across most markets, while the generation mix became more polarized between record photovoltaic output and falling coal generation. The region is moving into summer with signs that midday oversupply and evening scarcity are taking a more central role in market outcomes.
In day-ahead trading, HUPX baseload settled at €105.20/MWh, down €3.94/MWh week-on-week. German prices fell more sharply to €94.90/MWh. Serbian SEEPEX averaged €105.71/MWh, making Serbia the most expensive market in the core SEE region, while Greece was the cheapest at €86.77/MWh.
Italy North remained structurally disconnected from the rest of the region at €123.87/MWh, keeping a premium of almost €19/MWh versus Hungary. These relative price levels formed part of the broader pattern of lower averages across the area during CW22.
Photovoltaic surge lifts midday supply and weakens daytime pricing
The key development in CW22 was a surge in photovoltaic generation across Southeast Europe. Regional solar output reached a new record peak of 11,251 MW, up by 1,590 MW from the previous week and more than 3 GW above the same week of 2025. Solar output increased across Bulgaria, Romania, Greece, Hungary and Serbia.
Daytime pricing continued to weaken as solar output rose. Negative prices remained a regular feature in Hungary, where HUPX recorded 12 negative-price hours, compared with 15 hours in the prior week. Prosumer production also reduced measured grid demand during daylight periods.
Even as temperatures rose and cooling demand began to appear, total regional consumption fell to the lowest level since May 2025. The report attributes this to rooftop solar generation suppressing grid consumption during daylight hours, creating an artificial demand reduction visible in transmission system data.
Coal output falls to new lows as gas covers residual evening demand
Coal-fired generation reached a new historical low across Southeast Europe during CW22. Average regional coal output fell to 3,743 MW, down 505 MW week-on-week and almost 945 MW below the same period last year. The largest decline occurred in Serbia, where coal generation dropped by 371 MW versus the previous week and by 585 MW year-on-year.
Serbia still accounted for approximately 40% of all coal generation in Southeast Europe, but the trend is described as clearly downward. The reduction is linked to weaker demand, stronger solar production and operational limitations across lignite fleets. Coal’s declining role matters for evening pricing because coal historically provided support during evening peaks.
As coal output falls, markets increasingly rely on gas-fired generation after solar sunset. Gas-fired generation rose sharply to 3,608 MW, up 555 MW week-on-week and reaching its highest level since early April, with Greece contributing most while Hungary and Romania also added volume.
The report highlights a spring 2026 pattern: solar increasingly determines midday pricing while gas determines evening pricing. It also notes that this combination leads to greater intraday volatility rather than consistently high or low price levels across sessions.
Austrian CEGH gas prices eased to €48.60/MWh during CW22, while carbon prices moved higher to €78.83/tCO₂, their highest level since February . Higher EUA prices continue to affect thermal generation costs alongside the changing economics of solar production during daylight hours.
Hydrology weakens; Serbia’s balance deteriorates while Greece exports
Hydro performance was another notable feature of CW22. Regional hydro generation declined to 6,412 MW, with Danube inflows remaining well below seasonal norms at about 53% below historical averages for this period . Hydro output was particularly weak in Serbia and Albania.
The report flags hydrology as a potential risk for the remainder of summer. Weak reservoirs combined with stronger cooling demand could increase dependence on gas-fired generation during July and August, even though current conditions are partially masked by exceptional solar performance.
The largest country-specific change involved Serbia’s power balance deterioration. Serbia recorded a net import position of approximately 1,228 MW, worsening by more than 600 MW week-on-week and ranking among the weakest levels ever recorded according to the report . Lower coal generation, reduced hydro output and weaker wind production contributed to the shift.
Serbian generation during CW22 comprised approximately 1,278 MW coal, 840 MW hydro, 170 MW solar and 25 MW gas, with limited wind contribution . Domestic consumption stayed relatively stable at 3,268 MW, resulting in increased import dependence.
The report notes that this matters for traders because Serbia is becoming more exposed to regional price signals and cross-border congestion. It also states that export capability during summer peaks is declining as solar growth remains slower than in Romania, Bulgaria and Greece.
Nuclear weakness and cross-border flows shape regional fundamentals
Greece strengthened its position during CW22 as net exports averaged 1,512 MW, among the highest levels ever recorded . Strong solar generation, substantial gas-fired output and improving transmission utilization enabled Greece to export aggressively despite rising domestic demand.
This reinforced Greece’s role as a balancing hub for Southeast Europe. With new interconnections alongside expanding renewable capacity and future storage projects mentioned by the report, Greece is described as acting increasingly as a regional exporter rather than a peripheral market.
Nuclear generation remained unusually weak across the region. Regional nuclear output averaged only 3,098 MW, among the lowest levels ever recorded due to planned maintenance in Hungary, Romania and Bulgaria plus several unplanned outages . Nuclear output was almost 1 GW below the same week in 2025.
The report expects additional baseload supply as reactors return during the second half of summer could place downward pressure on regional prices and reduce gas burn requirements . Transmission dynamics were mixed during CW22 as imports from CORE markets into Southeast Europe increased substantially to a three-week high amid weaker regional fundamentals.
At the same time, Germany-to-Hungary transfer capability under flow-based market coupling remained extremely constrained and among the weakest levels observed since 2024 . The region also maintained positive exports toward Ukraine and Moldova for a 35th consecutive week, although volumes declined versus earlier weeks; these exports continue influencing congestion patterns during critical evening hours .
CW22 themes for June and summer: solar midday pricing and gas evening marginality
The outlook for June and summer 2026 points to three structural themes emerging from CW22 . First, solar generation has become the dominant driver of daytime price formation across Southeast Europe, with negative pricing embedded in market structure rather than appearing only occasionally.
The second theme is that gas-fired generation is increasingly marginal in evening periods. This contributes to larger spreads between midday and evening prices while strengthening the business case for battery storage projects across Hungary, Romania, Bulgaria, Greece and eventually Serbia .
The third theme concerns divergence within the region: Serbia’s deteriorating generation balance contrasts with Greece’s strengthening export position . For investors evaluating renewables projects based on annual MWh production versus evening peak value capture needs are highlighted by the report . Solar-only assets face growing cannibalization risk while solar-plus-storage and flexible gas-backed portfolios are described as becoming more strategically valuable as Southeast Europe enters summer demand season .
