Average peak electricity price in Southeast Europe (SEE) in summer 2024.
2026 Monitoring Report to the Energy Union Task Force
In summer 2024, Southeast Europe experienced a sustained period of electricity price spikes. In response, the European Commission requested ACER to assess the feasibility of measures that could help prevent or mitigate similar episodes across the region in the future.
Today, ACER publishes its report to the Energy Union Task Force, setting out recommendations to increase cross-zonal capacity and system flexibility across Southeast Europe1.
What did ACER monitoring find?
The 2024 price spikes in Southeast Europe were driven primarily by a lack of flexible resources to quickly replace solar generation in the evening hours, during periods of high demand.
Limited cross-border capacity, including due to planned network maintenance, constrained the region’s ability to import lower-priced electricity from the rest of the EU, reducing the extent to which market integration could mitigate higher prices.
Although prices in 2025 did not reach the same levels as in the summer of 2024, the price gap between Southeast and Central Europe2 persisted throughout 2025 and into early 2026. This suggests that the 2024 spikes were not just a one-off event, but a sign of deeper structural challenges in the region.
ACER found that a more efficient use of the available network capacity between Southeast Europe and the rest of the EU could have helped further ease the regional system stress in 2024.
While increasing interconnection capacity would have lowered prices, unlocking system flexibility in the region is also key, given its current generation mix and market structure. Greater participation of demand response, storage and other flexible generation assets can play an important role in enabling the system to respond to sharp changes in demand and supply.
The report also sets out broader structural improvements in market design and system planning (some already under implementation) that are expected to deepen electricity market integration in Southeast Europe.
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.
What are ACER's recommendations?
Addressing the challenges in Southeast Europe’s electricity markets requires both immediate and long-term action:
Where deemed beneficial, transmission system operators (TSOs) should prioritise the deployment of grid-enhancing technologies (such as dynamic line rating and advanced line conductors) as a cheaper and faster alternative to network development.
TSOs should continue improving regional coordination, including through better outage planning coordination with a greater role for Regional Coordination Centres (RCCs) and wider usage of curative remedial actions in capacity calculation.
TSOs and Nominated Electricity Market Operators (NEMOs) should continue implementing EU legal requirements to integrate markets, including the minimum 70% cross-zonal capacity requirement, flow-based capacity calculation and allocation across Southeast and Eastern Europe, and market coupling with non-EU neighbours.
TSOs and national regulatory authorities (NRAs) in Central and Southeast Europe should aim to accelerate network investment projects with high impact on the interconnectivity of Southeast Europe.
Member States and NRAs should make best efforts to unlock system flexibility, such as by removing market barriers for small market participants and mobilising investments in flexibility.
Looking ahead
In the coming months, ACER will continue to monitor price developments in Southeast Europe and engage with the Energy Union Task Force to support the implementation of measures to mitigate future price spikes.
Although this report focuses specifically on Southeast Europe, many of its recommendations could also help reduce the growing price volatility observed more widely across the EU.
Highlights
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350 €/MWh
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147
Most severe price spikes that could have been avoided in SEE in summer 2024, if 70% of capacity had been made available.
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> 50%
Potential gain in available capacity from using dynamic line rating in capacity calculation.
Report
ACER’s report to the Energy Union Task Force:
- analyses the main drivers behind the observed price spikes in Southeast Europe during summer 2024; and
- recommends measures to increase cross-zonal capacities and system flexibility in the region to mitigate their reoccurrence in the future.
Infographic
This infographic provides an overview of the ten recommendations put forward by ACER to increase cross-zonal capacity and system flexibility in Southeast Europe.
Additional information
- Access the underlying datasets.