The most important development during calendar week 22 of 2026 was the continued structural shift in the Southeast European power system from conventional generation toward solar-led price formation. While average power prices fell across most markets, the underlying generation mix became increasingly polarized between record solar output and rapidly declining coal generation. The region is now entering the summer period with clear signs that midday oversupply and evening scarcity are becoming the dominant market characteristics.
Average HUPX baseload settled at €105.20/MWh, down €3.94/MWh week-on-week, while German prices fell more sharply to €94.90/MWh. Serbian SEEPEX averaged €105.71/MWh, becoming the most expensive market in the core SEE region, while Greece remained the cheapest at €86.77/MWh. Italy North remained structurally disconnected from the rest of the region at €123.87/MWh, maintaining a premium of almost €19/MWh over Hungary.
Solar becomes the dominant market driver
The defining feature of CW22 was the surge in photovoltaic generation.
Regional solar output reached a new record with peak generation of 11,251 MW, increasing by 1,590 MW from the previous week and standing more than 3 GW above the same week of 2025. Solar production increased across every major market, including Bulgaria, Romania, Greece, Hungary and Serbia.
This had several immediate consequences.
First, daytime prices continued to weaken, with negative prices remaining a regular feature in Hungary. HUPX recorded 12 negative-price hours, only slightly below the 15 hours observed the previous week. Second, prosumer production substantially reduced measured grid demand. Despite temperatures rising across the region and cooling demand beginning to emerge, total regional consumption fell to the lowest level since May 2025.
The market is therefore no longer reacting purely to weather-driven demand changes. Increasingly, rooftop solar generation is suppressing grid consumption during daylight hours, creating an artificial demand reduction visible in transmission system data.
Coal generation continues structural collapse
Coal-fired generation reached a new historical low across Southeast Europe.
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 compared with 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 clearly downward. The reduction reflects a combination of weaker demand, stronger solar production and ongoing operational limitations across lignite fleets.
Coal’s decreasing role is particularly important because coal historically provided price support during evening peaks. As coal generation falls, markets increasingly rely on gas-fired generation to cover residual demand after solar sunset.
Gas generation returns as evening marginal technology
Gas-fired generation rose sharply to 3,608 MW, increasing by 555 MW week-on-week and reaching its highest level since early April. Greece accounted for much of the increase, but Hungary and Romania also contributed.
This confirms a trend that has become visible throughout spring 2026:
Solar increasingly determines midday pricing while gas determines evening pricing.
The result is greater intraday volatility rather than uniformly high or low prices.
Although Austrian CEGH gas prices eased to €48.60/MWh, carbon prices moved higher to €78.83/tCO₂, their highest level since February. Rising EUA prices continue to place upward pressure on thermal generation costs and reinforce the economic advantage of solar production during daylight hours.
Hydrology becomes a growing concern
Another notable feature was weak hydro performance.
Regional hydro generation declined to 6,412 MW, with Danube inflows remaining significantly below seasonal norms. According to the report, inflows were approximately 53% below historical averages for this period. Hydro generation was particularly weak in Serbia and Albania.
For the remainder of summer, hydrology may become one of the key market risks.
Weak hydro reservoirs combined with stronger cooling demand could significantly increase dependence on gas-fired generation during July and August. That risk remains partially masked by exceptional solar performance at present.
Serbia emerges as the weakest power balance in the region
The most significant country-specific development was the deterioration of Serbia’s power balance.
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 all contributed.
Serbian generation mix during CW22 consisted approximately of:
- 1,278 MW coal
- 840 MW hydro
- 170 MW solar
- 25 MW gas
- limited wind contribution
At the same time, domestic consumption remained relatively stable at 3,268 MW. The result was a significant increase in import dependence.
For traders, this is increasingly important because Serbia is becoming more exposed to regional price signals and cross-border congestion. The country’s ability to maintain export capability during summer peaks is declining as solar growth remains slower than in neighboring Romania, Bulgaria and Greece.
Greece continues to strengthen its position
Greece was the strongest performer in the region.
The country achieved average net exports of 1,512 MW, among the highest levels ever recorded. Strong solar generation, substantial gas-fired output and improving transmission utilization allowed Greece to export aggressively despite rising domestic demand.
This development reinforces Greece’s growing role as the balancing hub of Southeast Europe.
Combined with new interconnections, expanding renewable capacity and future storage projects, Greece increasingly acts as a regional exporter rather than a peripheral market.
Nuclear remains a constraint
Nuclear generation remained unusually weak.
Regional nuclear output averaged only 3,098 MW, among the lowest levels ever recorded because of planned maintenance in Hungary, Romania and Bulgaria together with several unplanned outages. Nuclear generation was almost 1 GW below the same week in 2025.
As reactors gradually return to service during the second half of summer, additional baseload supply could place downward pressure on regional prices and reduce gas burn requirements.
Transmission and cross-border flows
Transmission dynamics remained mixed.
Imports from CORE markets into Southeast Europe increased substantially and reached a three-week high, reflecting weaker regional fundamentals. However, 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 compared with previous weeks. These exports continue to influence congestion patterns and support regional prices during critical evening hours.
Market outlook for June and summer 2026
Three structural themes are emerging from CW22.
The first is that solar generation has become the dominant driver of daytime price formation across Southeast Europe, with negative pricing now embedded in the market structure rather than an occasional event.
The second is that gas generation is increasingly becoming the marginal evening technology, creating larger spreads between midday and evening prices and strengthening the business case for battery storage projects across Hungary, Romania, Bulgaria, Greece and eventually Serbia.
The third is that Serbia’s deteriorating generation balance stands in contrast to Greece’s strengthening export position, highlighting a growing divergence inside the Southeast European power market.
For investors, traders and banks evaluating renewable projects, CW22 provides further evidence that future project value will depend not only on annual MWh production but increasingly on the ability to capture value during evening peak periods. Solar-only assets face growing cannibalization risk, while solar-plus-storage and flexible gas-backed portfolios are becoming more strategically valuable as Southeast Europe enters the summer demand season.