The rapid expansion of renewable energy in Southeast Europe is highlighting significant challenges in grid infrastructure that could impede the region’s energy transition. Countries including Serbia, Bosnia and Herzegovina, North Macedonia, Montenegro, and Albania are witnessing a surge in solar and wind project pipelines, with national targets aiming for 40-50% renewable electricity shares by 2030. Serbia, for instance, is targeting a 45.2% share of renewables, while Albania is enhancing its predominantly hydroelectric system with large-scale solar capacity.
While the region appears poised for a swift transition to renewable energy on paper, the reality is that the focus has shifted from generation capacity to grid capability. The existing electricity systems are struggling to integrate the increasing volumes of renewable energy being produced, particularly solar power, which is concentrated both temporally and geographically.
Current assessments indicate that system adequacy remains intact across Southeast Europe. Countries like Serbia and Montenegro are not expected to encounter structural supply shortages under normal operating conditions. However, the operational challenges are becoming more pronounced as renewable generation peaks align with midday hours, leading to localized congestion and temporal imbalances.
This situation results in electricity being abundant when demand is low and constrained when demand peaks. The grid, originally designed for dispatchable thermal and hydro power sources, finds it difficult to accommodate these new patterns of generation. In response, transmission operators in Serbia have begun linking connection procedures for variable renewable energy to system capability, indicating that demand for connections is outpacing the grid’s current capacity.
Congestion has evolved into a structural characteristic of Southeast European electricity markets. In regions heavily reliant on solar energy, midday generation often surpasses local demand and export capabilities. This imbalance leads to price compression during peak solar hours and necessitates curtailment of renewable output. Evening demand spikes further complicate the situation as they require dispatchable or imported power at higher prices; intraday price spreads can reach €30-70/MWh or even exceed €100/MWh in extreme cases.
The geography of Southeast Europe underscores the importance of cross-border transmission infrastructure for maintaining system stability. The region’s interconnections with Hungary, Romania, Bulgaria, Croatia, and Greece were primarily designed for different flow patterns that do not align with the current dynamics driven by renewable generation and market price differentials.
To address these challenges, several critical projects are underway or planned. These include the Gacko–Brezna 400 kV corridor linking Bosnia and Montenegro, Trans-Balkan 400 kV upgrades connecting Serbia with its neighbors, and reinforcements along the Trebinje–Podgorica axis. Such projects represent essential investments needed to unlock renewable capacity and facilitate regional market integration.
In addition to transmission issues, flexibility within power systems has emerged as another core constraint. The traditional reliance on coal and hydroelectric sources has limited the ability to provide rapid-response balancing as renewable penetration increases. The need for fast-ramping capacity and short-term balancing resources is becoming critical as battery storage solutions gain traction across the region. However, deployment remains limited compared to actual requirements.
Distribution networks also pose a hidden bottleneck in this evolving landscape. Many new solar installations connect at lower voltage levels that were not designed for high levels of distributed generation or two-way power flows. This results in localized congestion even when transmission capacity exists and growing connection queues at distribution levels.
The current market design in Southeast Europe does not fully align with the operational realities of a renewable-dominated system. Key gaps include limited ancillary service markets, weak price signals for flexibility resources, incomplete integration of storage solutions, and regulatory barriers that hinder cross-border optimization.
For developers of renewable projects, these constraints translate into tangible financial risks such as curtailment during peak generation periods and lower-than-expected capture prices. This creates a two-tier market where location and integration capability significantly influence project viability.
As industrial demand rises—particularly from energy-intensive sectors seeking low-carbon electricity—the pressure on existing infrastructure intensifies. These industries require reliable electricity that aligns with their production schedules, reinforcing the need for integrated solutions combining generation, storage, and transmission capabilities.
Looking ahead, coordinated investment across multiple layers of the energy system will be essential. Accelerating transmission expansion—especially cross-border projects—and scaling up storage deployment will be critical steps toward managing variability effectively. Market designs must evolve to support these changes by introducing stronger price signals and enabling new participants such as aggregators.
Southeast Europe stands at a pivotal moment in its energy transition journey. While it possesses ample resources and policy direction to expand renewable energy significantly, achieving this potential hinges on developing supportive infrastructure and cohesive system design capable of integrating these advancements efficiently.
