Nuclear generation stands as a critical component of the energy mix in South-East Europe, particularly in Bulgaria and Romania, where it significantly influences pricing dynamics and market stability. Recent analyses indicate that while nuclear power provides essential baseload stability, it also contributes to peak price volatility due to its inherent operational limitations.
Bulgaria’s nuclear facilities account for approximately one-third of the country’s total electricity generation, offering a reliable and low-cost source of energy. This substantial contribution enables Bulgaria to maintain supply adequacy even during periods of heightened demand and price surges. For instance, in January 2026, despite regional price spikes, the stable output from nuclear power played a pivotal role in ensuring that supply remained sufficient.
However, the structural characteristics of nuclear energy present a paradox. While it helps to suppress average electricity prices, its inflexibility poses challenges during periods of peak demand. Nuclear plants operate at fixed output levels and lack the capacity to adjust production quickly in response to fluctuations in demand or disruptions caused by renewable energy sources. Consequently, during critical stress events, such as those witnessed earlier this year when daily prices soared to €282.33/MWh, the inability of nuclear generation to ramp up resulted in gas and imports setting the marginal price instead.
Romania reflects a similar scenario but with less intensity. Although nuclear power serves as a stable baseload resource, its limited share within the national energy portfolio means it cannot effectively manage pricing during stressful conditions. The reliance on hydroelectric power further complicates matters; when hydro outputs diminished in January, gas and imports quickly took over as marginal suppliers, driving prices above €150/MWh.
This structural paradox underscores the dual role of nuclear power: it reduces overall dependence on gas for electricity generation but fails to alleviate gas’s marginal role during high-demand periods. By securing a significant portion of baseload capacity through inflexible nuclear units, the system becomes increasingly reliant on flexible resources—like gas—to manage variability and ensure reliability.
The interaction between nuclear and renewable energy sources adds another layer of complexity. High levels of wind or solar generation can lead to curtailment risks when nuclear output remains constant. Conversely, during times of low renewable production, nuclear cannot compensate for sudden shortfalls, thereby widening gaps in system flexibility.
Looking forward, modernization efforts aimed at extending the operational life of existing nuclear plants may help sustain their baseload contributions; however, these initiatives are unlikely to alter their fundamental operational constraints. Discussions surrounding small modular reactors remain speculative and are not expected to yield immediate impacts within the near-term market context.
In conclusion, while nuclear power serves as an average-price stabilizer within South-East Europe’s electricity markets, it is essential for market participants to recognize its limitations regarding peak risk mitigation. Effective trading strategies and system planning must account for the critical role that flexible marginal assets play alongside a stable but inflexible baseload provided by nuclear generation.
