As Southeast Europe approaches 2025, nuclear energy emerges as a crucial component of the region’s electricity generation landscape. While renewable sources like solar and wind are gaining traction, the stability provided by nuclear power is indispensable for maintaining grid reliability, mitigating price volatility, and ensuring energy security. This dynamic positions nuclear energy as a foundational element in the evolving power systems of countries across the region.
Bulgaria stands out as the leading nuclear energy producer in Southeast Europe. The Kozloduy nuclear power plant, featuring two operational VVER units with a total capacity of 2,000 MW, generates between 14 and 16 TWh annually. This output accounts for over one-third of Bulgaria’s total electricity generation, making it a critical player in the national energy mix. The predictability of nuclear energy allows Bulgaria to maintain its status as one of Europe’s largest net electricity exporters, with annual net exports ranging from 10 to 12 TWh. This stability not only strengthens Bulgaria’s trade balance but also enhances investor confidence in its energy system.
Romania follows closely as another significant nuclear contributor. The Cernavodă plant operates two CANDU 6 reactors with a combined capacity of approximately 1,400 MW, producing around 10 to 11 TWh annually. This output represents about 18 to 20 percent of Romania’s electricity consumption. The high capacity factors of these units—often exceeding 85 to 90 percent—allow Romania to stabilize its supply curve while reducing reliance on fossil fuels. Plans to complete additional units in the coming decade could elevate nuclear’s share of Romania’s energy supply to over 30 percent, positioning the country as a regional exporter and engineering hub.
Hungary’s Paks nuclear facility plays a vital role in the regional context. With four operational units generating between 15 and 16 TWh per year, Paks covers nearly half of Hungary’s electricity needs. Although Hungary is not consistently a net exporter like Bulgaria, its nuclear infrastructure significantly mitigates dependence on gas imports and stabilizes cross-border electricity prices that affect neighboring countries such as Romania and Serbia. The planned Paks II expansion reflects a commitment to enhancing energy sovereignty through nuclear development.
Slovenia contributes to regional stability through its Krško nuclear power plant. Jointly owned with Croatia, Krško has a capacity of about 700 MW and typically produces between 5 and 6 TWh annually. This production supports both Slovenia and Croatia by providing stable baseload electricity that reduces import dependency for Croatia, which consumes approximately 16 to 18 TWh annually. Discussions around extending Krško’s operational life or potentially adding new units highlight its strategic importance in balancing renewable energy variability.
The absence of nuclear power in several Southeast European countries highlights stark contrasts. Nations such as Serbia, Bosnia and Herzegovina, Montenegro, Albania, and North Macedonia rely heavily on lignite, gas, hydro, and an increasing share of renewables without any nuclear generation capabilities by 2025. This lack of a stable baseload source exposes these countries to volatility from fossil fuel markets and increases their reliance on imports during periods of high demand or low generation capacity from renewables.
The collective output from existing nuclear facilities across Southeast Europe is substantial. Bulgaria contributes approximately 15 TWh per year, Romania around 10 to 11 TWh, Hungary between 15 and 16 TWh, and Slovenia roughly 5 to 6 TWh. Together, these facilities produce over 40 TWh annually—equivalent to the entire annual electricity consumption of Serbia. This firm baseload generation is critical for maintaining grid stability amid increasing renewable penetration.
Nuclear power also plays a pivotal role in dampening wholesale price fluctuations. By providing consistent baseload volumes, it reduces market exposure to gas and coal price spikes. Additionally, it enhances export capabilities for countries like Bulgaria and Romania by ensuring reliable supply during periods when renewable output may be inconsistent. Each TWh generated by nuclear effectively displaces fossil fuel generation that would otherwise incur carbon costs under various regulatory frameworks.
Operationally, nuclear serves as an essential backbone for integrating renewables into the energy mix. While not flexible like gas or hydro resources, nuclear provides the necessary stability that allows variable renewable sources to flourish without compromising reliability. In Bulgaria and Romania, the combination of nuclear with other energy sources facilitates effective management of fluctuating renewable outputs.
The future trajectory for nuclear investment in Southeast Europe appears optimistic. Countries are increasingly recognizing the strategic importance of expanding their nuclear capabilities rather than moving away from them. Bulgaria is pursuing new developments at both Belene and Kozloduy plants; Romania is advancing its expansion plans; Hungary is committed to Paks II; and Slovenia is evaluating its options regarding Krško’s future operations—all indicative of a broader trend toward strengthening non-fossil baseload power generation across the region.
The implications for countries without nuclear capabilities are significant. They must navigate an evolving landscape where reliance on gas and hydropower becomes more pronounced while managing higher capital expenditures for flexibility infrastructure. As Southeast Europe moves towards greater integration of renewable energy sources through 2030 and beyond, the stabilizing role of nuclear power will become increasingly vital for ensuring system reliability and economic competitiveness.
