As Europe accelerates its energy transition, the role of South-East Europe (SEE) is becoming increasingly critical, yet simultaneously constrained by grid limitations. The region, which serves as a vital link between EU member states and the Western Balkans, faces significant challenges in expanding its electricity transmission and distribution networks. This situation threatens to undermine not only the region’s renewable energy ambitions but also its integration into the broader European energy market.
Recent data reveals that approximately 120 GW of planned renewable capacity across Europe is jeopardized due to inadequate grid infrastructure, with transmission constraints alone responsible for a shortfall of about 104 GW. Romania and Bulgaria emerge as key players in this context, acting as essential transit points within the SEE-EU electricity interface. Their grid limitations are not isolated; they have far-reaching implications for cross-border electricity flows, congestion pricing, and overall market integration.
The evolving landscape necessitates a reevaluation of how SEE is perceived in the energy sector. The region is transitioning from being viewed merely as a low-cost industrial periphery to a crucial balancing zone for Europe’s energy system. The ability to manage grid capacity effectively will determine whether objectives related to EU decarbonization and energy security can be achieved.
Data indicates that certain systems in SEE may only accommodate less than 10% of anticipated renewable additions by 2030 under current grid conditions. This is particularly alarming given that many countries in the region are expected to experience some of the highest growth rates in renewable energy deployment across Europe.
This dual-layered risk presents challenges at both project and system levels. Developers are increasingly facing uncertainties regarding connection timelines and curtailment risks, which complicates financial viability. As a result, bankability is shifting from traditional metrics like resource quality to grid-specific factors. Moreover, if these constraints persist, SEE risks becoming a bottleneck in Europe’s energy transition, impeding the flow of surplus renewable generation across borders.
The implications extend into industrial strategy as well. Electrification is becoming central to Europe’s competitiveness agenda, impacting sectors such as manufacturing and hydrogen production. However, in critical systems like Bulgaria and Romania, there is virtually zero available transmission capacity for new large-scale industrial loads. This reality fundamentally alters investment decisions, with access to reliable electricity infrastructure now taking precedence over historical factors such as labor costs or tax regimes.
Countries that can enhance their hosting capacity and streamline connection processes are likely to position themselves favorably as near-shoring hubs for EU industries. Conversely, those unable to adapt may remain marginally integrated into the European market while missing out on potential investment flows.
At the distribution level, many European systems still possess sufficient capacity for household electrification—grids can support heat pumps in 13–32% of homes and EV chargers in 7–18%. However, this does not guarantee uniform progress across all demand layers. While residential electrification may continue to grow thanks to more flexible distribution networks, large-scale industrial demand remains hindered by transmission bottlenecks.
The situation is compounded by a significant backlog in connection requests; nearly 700 GW of renewable projects are currently awaiting grid connection across reporting countries. In several instances, project pipelines exceed existing system capacities significantly. This mismatch between project announcements and infrastructure readiness raises concerns about the viability of many proposed initiatives.
The need for reform in connection processes and prioritization mechanisms has never been more pressing. Countries like France and Spain have already implemented competitive allocation systems for grid capacity that could serve as models for SEE. France has pre-allocated around 71 GW specifically for renewable integration, while Spain utilizes a tender-based approach to mitigate speculative congestion.
The analysis highlights that non-wire solutions—such as dynamic line rating and advanced monitoring technologies—could unlock an additional 140 GW to 185 GW of capacity without necessitating immediate large-scale infrastructure expansions. These approaches could be particularly beneficial in SEE, where traditional grid expansion often faces financial and bureaucratic hurdles.
The urgency of addressing these infrastructural challenges is underscored by European policy initiatives like the Grid Action Plan (2023) and the upcoming European Grid Package (2025). While these frameworks aim to accelerate grid investment and improve connection processes, implementation remains fragmented across individual countries within SEE.
This decentralization presents both opportunities and risks. It allows countries to differentiate themselves as attractive investment destinations but also risks creating fragmentation that could weaken regional integration efforts. The interconnectedness of SEE’s markets—linking Serbia, Romania, Bulgaria, Hungary, Greece, and the Western Balkans—means that constraints in one area can ripple through the entire network, affecting price formation and market stability.
The increasing penetration of renewables exacerbates these dynamics; curtailment risks rise in constrained areas while neighboring markets may experience volatility due to limited transfer capacities. For investors operating within this complex environment, project economics hinge not only on local conditions but also on regional interconnections.
The interdependence between SEE and EU markets is deepening but is contingent on physical capacity and operational flexibility rather than mere regulatory alignment or market coupling. Countries that align their transmission expansion efforts with distribution investments will be better positioned to attract future energy and industrial investments.
The focus for energy strategy in SEE must shift towards ensuring connection certainty rather than merely announcing pipeline projects or setting installed capacity targets. The region’s potential remains substantial; however, realizing it hinges on overcoming critical infrastructural constraints that currently impede progress.
The transition from ambition to execution now rests on whether electrons can flow efficiently across borders into industries at the required scale. The future trajectory of Europe’s energy system increasingly depends on developments along South-East Europe’s transmission corridors—where capacity management will dictate what becomes feasible.
