The electricity markets in Southeast Europe (SEE) have opened the week with a notable increase in spot prices, reversing the previous weekend’s downward trend. Key exchanges such as HUPX, OPCOM in Romania, and Bulgaria’s IBEX reported price surges to €138.68/MWh, €139.51/MWh, and €136.34/MWh respectively. This upward movement reflects daily gains ranging from €35 to €42/MWh across most markets, while Greece remained insulated from these increases, trading at €97.12/MWh due to favorable solar conditions.
This shift in market dynamics can be attributed to a combination of factors including a significant drop in wind generation, reduced hydro output, ongoing nuclear maintenance, and rising evening peak prices. Regional electricity consumption has climbed to 28.1 GW, yet total generation has decreased to 21.7 GW, resulting in a net import requirement of approximately 2.16 GW. Notably, hydro generation saw a day-on-day decline of 615 MW, while wind output plummeted by 725 MW, contributing to tighter balancing conditions.
The current generation mix highlights the vulnerability of the SEE market during periods of renewable volatility. Hydro energy accounted for only 22% of the total mix, with wind contributing a mere 3%. This situation has necessitated increased reliance on coal and gas-fired generation, with coal output rising by 156 MW and gas-fired generation remaining steady at 3.49 GW. Although solar generation improved by 331 MW, it was insufficient to mitigate the pronounced evening scarcity premium observed across regional price curves.
Hourly pricing data indicates a resurgence of thermal stress pricing, with HUPX evening prices trading at or above €200/MWh and peaking at €200.9/MWh for the day. Romania’s OPCOM recorded even higher peaks at €212.2/MWh, while Bulgaria’s maximum hourly prices approached €177.6/MWh. The stark contrast between midday prices and evening rates underscores the growing volatility in intraday spreads driven by renewable energy penetration without adequate storage solutions.
Furthermore, the import structure reveals a renewed dependence on north-to-south electricity flows. Imports from Austria and Slovakia into Hungary and the broader SEE region remain elevated at about 1.9 GW, with Italy continuing to absorb excess regional capacity. Greece is also positioned as a net importer at approximately 1.29 GW, while Hungary maintains substantial import needs.
Several supply-side developments are reinforcing bullish sentiment in the market. Bulgaria’s Kozloduy nuclear plant has begun preparations for maintenance on Unit 5, which will last until mid-June, removing a critical baseload asset during a time of already volatile renewable availability. This maintenance will involve refueling with Westinghouse fuel assemblies as Bulgaria seeks to diversify its nuclear fuel sources away from Russia.
In Romania, an extended outage for Cernavoda Unit 2 due to transformer issues has further constrained nuclear capacity in the region. The ongoing maintenance of Unit 1 exacerbates concerns regarding Romanian export capabilities in the near term.
Slovenia’s Krško nuclear plant is also facing limitations on its export capacity due to low river levels affecting cooling systems; exports have been reduced to around 690 MW compared to typical levels exceeding 700 MW. This situation illustrates growing structural risks across Europe’s thermal and nuclear fleets as climate-related hydrological constraints impact operational efficiency.
Weather forecasts indicate that temperatures across SEE and Hungary may decline after May 11th, particularly affecting Slovenia, Croatia, Bulgaria, and Romania—potentially leading to increased thermal demand amid uncertain wind recovery.
Forward markets reflect this tightening structure with Hungarian Week-20 power forwards climbing to €126/MWh and Week-21 contracts reaching €124.5/MWh. Carbon allowances have also strengthened significantly, with EUA Dec-26 contracts trading near €80/t—adding pressure on coal and lignite generation economics throughout SEE.
Despite these challenges, there remains robust momentum for renewable investments in the region. North Macedonia has reported that its solar capacity has reached 962.6 MW—now surpassing hydropower as the second-largest source of installed generation technology—while renewables account for 46.4% of its electricity mix. Additionally, Montenegro has initiated trial operations at its Gvozd wind farm near Nikšić, expected to generate around 150 GWh annually for approximately 25,000 households.
However, the current market dynamics suggest that merely expanding renewable capacity is insufficient for stabilizing SEE electricity markets. The widening gap between midday and evening pricing highlights persistent import dependencies alongside tightening nuclear availability and variable hydro performance—all underscoring the urgent need for enhanced utility-scale battery storage solutions and flexible gas generation capabilities.
Without significant advancements in flexibility infrastructure, the SEE market risks entering a more volatile phase characterized by aggressive intraday pricing spikes coinciding with high renewable penetration during periods of weak wind output and limited hydro resources.
