Southeast Europe is experiencing a significant shift towards a renewable-heavy electricity system, characterized by the expansion of wind and solar projects across countries such as Serbia, Romania, Greece, Bulgaria, Montenegro, Albania, and Bosnia and Herzegovina. As battery storage technologies advance from concept to implementation, hydropower is regaining its role as a critical low-carbon resource. However, the region’s market architecture is lagging behind this rapid development.
A major concern is the absence of an integrated regional balancing market, which is increasingly vital as renewable energy sources contribute to greater volatility in power generation. By 2026, the lack of such a mechanism could pose significant risks for electricity trading in Southeast Europe (SEE).
The traditional Balkan power system was structured around national dispatch strategies, with Serbia relying on lignite and hydroelectric power, Romania balancing nuclear and renewables, and Greece incorporating gas and imports. This nationalized approach to balancing is becoming obsolete as renewable energy generation does not adhere to borders; for instance, weather patterns affecting wind or solar output can simultaneously impact multiple countries.
This disconnect creates heightened system stress. Without a cohesive balancing framework, SEE markets may face ongoing congestion issues, curtailment of renewable energy output, spikes in imbalance costs, and inefficient procurement of reserves. Such challenges will likely lead to wider price spreads that are not necessarily tradable, increased financing costs for developers, more frequent interventions by Transmission System Operators (TSOs), and heightened volatility for industrial consumers.
The transition towards renewables thus hinges on effective market design rather than solely on infrastructure improvements. While battery storage can enhance flexibility—evidenced by Serbia’s planned 4.54 GWh storage pipeline—its effectiveness is contingent upon transparent participation in balancing markets and cross-border trading. Fragmented regulations may limit the benefits of battery systems and fail to address regional inefficiencies.
Hydropower assets in Albania, Montenegro, and Romania represent valuable flexible resources that could stabilize systems across borders if integrated into a well-functioning balancing market. Conversely, without coordination among these resources, their potential remains underutilized.
The physical infrastructure supporting these transactions includes key transmission corridors such as the Trans-Balkan Corridor, Montenegro–Italy cable, Greece–Bulgaria links, and Romania–Hungary interconnections. However, simply having these connections is insufficient; there must be accompanying market rules that facilitate efficient movement of balancing energy and reserves across borders.
Data from the Energy Community indicates that commercial electricity exchanges between the EU and Western Balkans fell by approximately 25%, highlighting that price signals alone do not ensure efficient flows when hindered by carbon constraints or inadequate market designs.
To effectively manage the impending renewable cycle, SEE requires coordinated reserve procurement strategies, harmonized imbalance rules, enhanced intraday liquidity frameworks for regional storage participation, and TSO collaboration that recognizes flexibility as a shared resource across borders.
The implications for financing are significant. Investors will be more inclined to support storage and hybrid projects if they can identify clear revenue opportunities within stable regulatory frameworks. A battery system limited to local arbitrage carries higher risk compared to one that can also generate income from balancing services or regional congestion relief efforts.
Manufacturers in Serbia, Romania, and Greece are increasingly seeking renewable-backed electricity; however, achieving stable supply profiles necessitates depth in balancing capabilities. The absence of regional integration complicates the structuring and pricing of renewable Power Purchase Agreements (PPAs).
The urgency lies in timing: rapid deployment of renewables may outpace market integration efforts. If Southeast Europe delays addressing these challenges until volatility escalates significantly, it could face severe repercussions including stranded renewable outputs and rising balancing charges—a scenario already observed in Western Europe.
Despite these challenges, Southeast Europe possesses several advantages: inherent hydro flexibility resources, manageable levels of renewable penetration in various markets, improving interconnections among nations, and an increasing interest from investors in storage solutions. These strengths can only become strategic assets if effectively transformed into a cohesive regional balancing architecture.
The future landscape of electricity trading in SEE will favor those nations capable of establishing liquid and tradable flexibility across borders rather than merely those boasting higher capacities of wind or solar generation. Without such developments in place, the region risks being overwhelmed by renewable volatility before adequate mechanisms can be established to manage it effectively.
