After the 2024 electricity price spikes in Southeast Europe, ACER recommends measures to mitigate future periods of system stress in the region

In summer 2024, Southeast Europe¹ experienced a sustained period of electricity price spikes. In response, the European Commission asked ACER to assess which measures could help prevent or mitigate similar episodes across the region in the future. 

Today, ACER publishes its Monitoring Report to the Energy Union Task Force, setting out recommendations to increase cross-zonal capacity and system flexibility across Southeast Europe.

What did ACER find? 

• The 2024 price spikes were driven mainly by a lack of flexible resources to replace solar generation in the evening, during periods of high demand. 
• Limited cross-border capacity, including due to planned network maintenance, reduced the region’s ability to import lower-priced electricity from the rest of the EU.
• Although prices in 2025 did not reach the same levels as in summer 2024, the price gap between Southeast and Central Europe² persisted into early 2026. This suggests deeper structural challenges in the region. 

ACER found that a better use of the existing network could have helped ease regional system stress in 2024. But increasing interconnection alone is not enough – greater system flexibility is also key. 

What does ACER recommend?

Addressing the challenges observed in Southeast Europe’s electricity markets requires both immediate and long-term action by Member States, national regulatory authorities, transmission system operators and other market actors:

• Faster deployment of grid-enhancing technologies (such as dynamic line rating and advanced line conductors).
• Improved regional coordination, including on outage planning and curative remedial actions in capacity calculation. 
• Continued implementation of EU market integration rules (minimum 70% cross-zonal capacity requirement, flow-based approach across Southeast and Eastern Europe, and market coupling with non-EU neighbours).
• Accelerated network investment projects to strengthen interconnectivity of Southeast Europe.
• Measures to unlock system flexibility by removing market barriers for small market participants and supporting investments in flexibility.
  
  ^{1. For the purpose of this assessment, Southeast Europe refers to the group of Member States affected by the price spikes: Slovenia, Croatia, Hungary, Romania, Bulgaria and Greece. 2. Central Europe refers to Austria and Slovakia.}