The energy landscape in South-East Europe is undergoing a significant transformation as the region pivots towards renewable energy sources. This shift is characterized by an evolving power grid, where transmission infrastructure has become the primary factor influencing market dynamics. Countries such as Serbia, Bosnia and Herzegovina, Montenegro, Albania, and North Macedonia are investing heavily in 400 kV interconnections, grid enhancements, and storage projects to create a more cohesive yet unevenly developed energy network.
This transition is not merely about increasing capacity; it represents a fundamental change in how electricity is distributed across the region. The previous model of isolated national systems is being replaced by a corridor-based framework that prioritizes high-voltage transmission lines and adapts to the patterns of renewable energy generation.
Central to this evolution is the Trans-Balkan electricity corridor, which is emerging as a critical infrastructure platform linking multiple countries, including Serbia, Montenegro, and Bosnia and Herzegovina, with broader EU markets. Project developments anticipated between 2025 and 2026 indicate that this corridor will facilitate enhanced cross-border electricity exchanges, particularly through new 400 kV overhead lines connecting Pljevlja in Montenegro to Bajina Bašta in Serbia and Višegrad in Bosnia and Herzegovina.
In addition to these connections, projects like the Gacko–Brezna and Brezna–Sarajevo 400 kV links are being advanced to alleviate congestion while integrating renewable energy sources across the western Balkans. These initiatives are crucial for accommodating increasing levels of solar and wind generation, especially in regions where traditional grid capacity has not kept pace with development needs.
Further east, the Kosovo–North Macedonia 400 kV corridor is being developed as part of a larger east-west transmission strategy that enhances connectivity with Albania. Concurrently, Albania is undergoing substantial grid upgrades, establishing new 400 kV connections with Kosovo and Greece while modernizing substations like Fierza to position itself as a potential hub for renewable energy exports.
The expansion of the 400 kV network is closely linked to the growth of renewable generation capacity and system flexibility. A notable project in this regard is the proposed Moglice pumped-storage facility in Albania, which aims to provide up to 1,620 MW of capacity along with approximately 30 GWh of storage. This facility will enhance balancing capabilities across interconnected national systems.
The need for robust interconnections and storage solutions stems from the inherent variability of renewable energy sources. As such, without these enhancements, transmission corridors may face congestion issues rather than facilitating efficient energy flow.
The design of new infrastructure increasingly reflects this necessity. For instance, planned 400 kV projects in northeastern Albania are specifically aimed at integrating over 1 GW of wind capacity, alleviating pressure on existing lower-voltage lines. Investments across the region are now strategically aligned with identifiable renewable energy projects rather than serving as generic upgrades.
Montenegro exemplifies this trend through its collaboration between EPCG and Masdar, focusing on large-scale solar and wind initiatives intended for export via existing connections to Italy. This approach positions transmission capacity not merely as infrastructure but as a vital economic asset for renewable energy monetization.
Serbia remains a pivotal player within this evolving framework. The country’s internal grid enhancements—particularly the 400 kV network linking Belgrade, Kragujevac, Kraljevo, and Niš—are projected to require investments between EUR 200–300 million. These upgrades aim to mitigate internal bottlenecks while bolstering north-south transfer capabilities through new lines like Kragujevac–Kraljevo and Obrenovac–Bajina Bašta.
Despite advancements at higher voltage levels, legacy infrastructure remains a challenge. The widespread use of the 220 kV network has been identified as a bottleneck that necessitates rehabilitation efforts such as those underway on the Trebinje–Perućica–Podgorica–Vau Dejës corridor. Upgrading these assets is essential for maintaining operational effectiveness amid increasing loads and renewable penetration.
The situation becomes even more pressing at the 110 kV level, where most renewable projects connect to the grid. Insufficient reinforcement at this tier can hinder effective electricity distribution, creating disconnections between generation capabilities and transmission infrastructure.
This evolving scenario has resulted in a three-tiered grid structure: an expanding and integrating 400 kV system, a stabilizing 220 kV system, and an increasingly stressed 110 kV system. These dynamics impact both physical electricity flows and market behaviors throughout South-East Europe.
<pElectricity markets in the region are beginning to reflect these structural changes. Enhanced cross-border capacities have led to increased trading volumes and reduced price disparities in well-connected areas such as Serbia-Hungary or Serbia-Romania corridors. However, congestion remains prevalent in less developed segments of the network, contributing to ongoing regional price divergences.
The implementation of negative pricing mechanisms alongside expanding balancing markets further accelerates this transition. Price signals are becoming more nuanced and reflective of physical constraints within the grid, thereby incentivizing flexibility through storage solutions and hybrid generation models.
Looking ahead toward 2030-2035, South-East Europe is unlikely to achieve a fully unified electricity market akin to Western European standards. Instead, the region appears set to develop into a complex system characterized by strong transmission interconnections alongside persistent local bottlenecks and uneven investment conditions.
This evolving landscape delineates three distinct investment geographies: a northern belt comprising Hungary, Romania, and northern Serbia; a transitional central layer involving Serbia’s internal grid along with parts of Bosnia and Bulgaria; and a southern periphery encompassing Albania, Montenegro, and parts of North Macedonia where significant renewable potential exists amidst developing transmission frameworks.
The ongoing transformation signifies that transmission corridors are becoming vital economic conduits within South-East Europe’s energy landscape. The value proposition for renewable projects increasingly hinges on their strategic positioning within this interconnected network—accessibility to 400 kV corridors, exposure to congestion effects, and integration capabilities will all play crucial roles moving forward.
This shift towards a corridor-driven regional market highlights the intricate interplay between transmission infrastructure development, renewable generation expansion, and storage capacity enhancement—a triad that will ultimately determine whether South-East Europe evolves into an integral component of the broader European energy system or remains marked by structural inefficiencies.
