The energy landscape in Southeast Europe is undergoing significant transformation as Serbia and Romania navigate their respective power systems. The period from 2025 to 2028 is poised to highlight critical shifts, particularly as Romania accelerates its coal retirements while Serbia maintains a stable dispatchable baseload. This divergence is becoming increasingly evident in national adequacy metrics, cross-border electricity flows, pricing mechanisms, and the overall risk profile affecting the Balkan-Central European region.
Romania’s power infrastructure is facing a notable contraction in dispatchable capacity, with an estimated 1.7 GW of lignite-fired generation scheduled for retirement by early 2026, primarily from the Oltenia region. Historically, these coal units have been crucial for providing baseload energy and ensuring reliability during winter months when hydroelectric output decreases and wind generation becomes unpredictable. As these units exit the market, Romania’s reserve margins are tightening at a time when demand is surging due to electrification trends and industrial recovery, with peak winter demand now nearing 9.0–9.5 GW.
In stark contrast, Serbia enters this same timeframe with a robust thermal base managed by Elektroprivreda Srbije, featuring over 4.4 GW of installed lignite capacity. Although these thermal units are aging, they continue to provide reliable output at marginal production costs between €25–35/MWh, excluding carbon costs. Additionally, Serbia’s hydro capacity exceeding 3.0 GW offers further support during peak demand periods. This enables Serbia to comfortably meet winter peaks of 7.5–8.0 GW, reducing its reliance on imports during critical times.
This shift in dynamics has transformed Romania’s role in regional electricity trade. Traditionally a net exporter to Hungary and intermittently to Serbia and Bulgaria during high hydro output periods, Romania is now facing an increasingly episodic export capability due to coal retirements. Under typical hydrological conditions combined with strong renewable generation, Romania can still engage in exports; however, adverse weather conditions can swiftly convert it into a net importer, straining the north-south corridors that connect it with Hungary and Serbia.
Serbia’s position in this evolving scenario is pivotal; it serves not merely as another competitor for imports but as one of the few regional systems capable of maintaining domestic balance without heavily relying on constrained cross-border interconnections. This ability allows Serbia to avoid importing electricity when neighboring countries like Romania, Bulgaria, or Hungary face their own supply challenges, thereby alleviating pressure on cross-border capacities that could lead to congestion or price spikes.
The volatility observed in Romanian day-ahead prices reflects these changes, particularly during winter stress events where price spikes have become more pronounced. In contrast, while Serbian prices are also rising overall, they remain more closely tied to lignite marginal costs during such periods. The price differential between Romanian and Serbian wholesale markets has widened significantly during cold spells—sometimes exceeding €20–30/MWh. Although transmission constraints limit complete convergence of prices across borders, these spreads indicate a substantial reallocation of scarcity rents within the region.
This evolving market landscape presents both opportunities and risks for investors. As Romania moves toward a model characterized by frequent scarcity pricing—enhancing revenue prospects for flexible assets such as storage solutions and gas peakers—it also increases financial exposure for energy-intensive industries reliant on stable pricing structures. Conversely, Serbia’s system indirectly capitalizes on reliability by mitigating volatility rather than exacerbating it—a factor that could influence decisions regarding industrial investments and long-term power purchase agreements within the region.
The transmission interface between Serbia and Romania plays a crucial role in this context; multiple 400 kV interconnections facilitate east-west and north-south electrical flows between the two nations. Although there is substantial technical transfer capacity available, commercial utilization often faces limitations due to N-1 security requirements and internal bottlenecks on both sides of the border. With the accelerated exit of Romanian coal capacity, these constraints are likely to become more pronounced during simultaneous stress events affecting Hungary and Bulgaria.
Investment estimates for enhancing the Serbia-Romania interface—whether through new transmission lines or upgrades—typically range from €200–400 million. Such capital expenditures are justified not solely by national adequacy needs but also through potential savings from reduced congestion costs and diminished price volatility across interconnected markets. Consequently, as Romanian coal exits accelerate, every additional megawatt of dependable transfer capacity from Serbia gains increased systemic value.
The contrasting carbon risk profiles between the two nations further complicate matters; Romania fully incorporates EU Emissions Trading System (ETS) costs into its operations which accelerates coal’s removal from merit order rankings. Meanwhile, Serbia remains outside EU ETS regulations for now and retains a short-term cost advantage due to its lignite resources. However, as Carbon Border Adjustment Mechanism (CBAM) initiatives develop alongside deeper regional market coupling efforts, Serbian exports will likely encounter implicit carbon pricing pressures that could affect competitiveness moving forward.
The operational risks faced by both countries illustrate their differing vulnerabilities: Romania’s shift towards variable renewables increases exposure to correlated weather impacts while Serbia’s reliance on asset reliability necessitates ongoing maintenance investments estimated at €300–450 million. Any disruptions within Serbia’s thermal or mining sectors could have significant repercussions given that Romania’s buffer capacity is diminishing rapidly.
The reliance on hydropower adds another layer of complexity; both countries depend on the Danube river basin but face correlated hydrological stress during harsh winters when inflows dwindle significantly. While Romania’s reduced thermal flexibility under such conditions amplifies its vulnerability to supply shortages, Serbia’s retained baseload generation acts as a stabilizing force amid heightened regional risks.
This divergence between Serbia and Romania signals broader implications for how uneven decarbonization efforts reshape regional power dynamics moving forward. Systems that transition away from coal without adequate dispatchable replacements may become increasingly sensitive to import dependencies and price fluctuations; conversely, those maintaining longer baseload capacities may play stabilizing roles but risk accumulating carbon exposure over time.
The future trajectory of both nations depends on strategic actions taken today: For Serbia to transform its current advantages into long-term value requires investments in cross-border grid enhancements and flexibility solutions that can eventually substitute lignite-derived system services; meanwhile Romania must seek effective means to replace lost baseload capabilities without destabilizing imports from neighboring countries.
As assessments from ENTSO-E continue to underscore the contrasting trends unfolding within each nation’s power system—tightening margins in Romania versus relative resilience in Serbia—the regional landscape for electricity flows is poised for recalibration toward areas with sustained dispatchable capacities. In this shifting environment, Serbia emerges not merely as an adjacent player but rather as an essential factor influencing whether Romania’s transition occurs smoothly or faces ongoing challenges.
