In South-East Europe (SEE), the interplay between cross-border electricity capacity and market volatility has emerged as a critical factor shaping the region’s energy landscape. As the energy transition accelerates, characterized by increasing reliance on renewable sources, congestion within the electricity grid has become a significant driver of price fluctuations. The ability to manage cross-border capacity effectively is not merely a technical consideration; it serves as an essential mechanism for mitigating electricity price volatility across interconnected markets.
The operational dynamics of the European electricity market rest on the premise that trade can alleviate scarcity. However, this principle hinges on the availability of interconnectors and effective market coupling. Despite physical interconnectors being present in many instances within SEE, operational constraints frequently prevent optimal utilization during periods of high demand or supply shortages. This misalignment leads to price divergences that are not solely attributable to demand or fuel costs but are significantly influenced by limitations in electricity movement across borders.
The summer of 2024 exemplified this issue, as South-East Europe faced severe evening price spikes driven by high temperatures and increased demand coinciding with diminished solar generation post-sunset. The inability to import cheaper electricity from neighboring regions exacerbated these conditions, highlighting the importance of sufficient cross-zonal capacities. According to analyses conducted by ACER, enhancing cross-zonal capacities could have substantially reduced both the frequency and intensity of these price spikes.
Quantitatively, compliance with the legally mandated 70% capacity requirement could have prevented nearly half of the most severe price spikes experienced during this period. Furthermore, implementing this rule might have led to an average reduction in peak prices by up to €78/MWh in central and south-east bidding zones. Such reductions are significant in economic terms, marking a clear distinction between stress pricing and crisis pricing for industrial consumers.
Strategically, countries within SEE face a pivotal choice when addressing energy scarcity: either overbuild domestic generation capacity or invest in regional interconnections and market coupling to access external surpluses when necessary. Overbuilding can lead to costly infrastructure with low utilization rates, while market integration presents a more cost-effective long-term solution that necessitates coordinated governance among transmission system operators (TSOs) and disciplined capacity allocation.
The implications for competitiveness in SEE are profound. Higher wholesale prices relative to Western European markets stem from structural factors such as generation mix and limited nuclear or hydroelectric resources. However, persistent price divergences are largely driven by cross-border capacity constraints. When these constraints limit market access, local scarcity is treated as if it were isolated from neighboring surpluses, adversely impacting industrial competitiveness and heightening political sensitivities surrounding electricity costs.
Moreover, cross-border capacity plays a vital role in facilitating decarbonization efforts within the region. As renewables like wind and solar become more prevalent, their inherent variability necessitates flexible import and export capabilities to balance supply against changing weather conditions. Interconnectors act as essential balancing mechanisms; their availability allows for better absorption of renewable energy resources while minimizing both curtailment during surplus periods and price spikes during deficits.
The early weeks of 2026 illustrated these dynamics clearly: following a surge in wind output in Week 01, prices fell significantly before rebounding sharply in subsequent weeks due to tightening conditions. This pattern underscores how interconnected markets can stabilize volatility when sufficient cross-border capacity is accessible; conversely, constraints lead each national market to experience isolated fluctuations.
Trading behaviors further emphasize the importance of managing congestion effectively. Increased liquidity and cross-border flows observed at the start of 2026 enabled traders to capitalize on volatility through transparent mechanisms that reflect genuine scarcity. Conversely, opaque or inconsistent practices regarding capacity allocation can create distortions that exacerbate political tensions around energy pricing.
Governance also plays a crucial role in managing cross-border capacity as an insurance mechanism against price volatility. TSOs must ensure accurate capacity calculations while regulators must prevent excessive withholding of capacity under security pretexts. The Energy Community’s ongoing efforts toward deeper integration highlight the necessity of completing market coupling initiatives to mitigate unnecessary exposure to volatility events.
The economic rationale for prioritizing cross-border capacity is compelling; fulfilling the 70% requirement could yield significant reductions in peak pricing across affected bidding zones. Thus, enhancing connectivity emerges as one of the most impactful strategies available for mitigating risk within SEE’s electricity markets.
As governments and regulatory bodies navigate these complexities, they must recognize congestion management as a core component of industrial policy. Fluctuations in electricity costs can significantly alter investment decisions within industries reliant on stable energy prices while also influencing public sentiment regarding energy affordability.
With ACER’s findings indicating that adherence to established capacity requirements could have mitigated numerous severe price spikes—totaling 147 during peak stress conditions—the imperative for strategic action becomes evident as stakeholders work towards ensuring greater stability within South-East Europe’s evolving electricity landscape.
