Electricity prices rose sharply across southeastern Europe during the summer of 2024, exposing structural weaknesses in the regional power market. The episode led European regulators to consider new measures intended to lower the risk of similar disruptions. Regulators linked the instability to conditions that developed during periods of high demand.
As concerns grew about prolonged price volatility, the European Commission asked ACER to examine the causes of the instability and propose solutions. ACER prepared a detailed report for the Energy Union Task Force. The recommendations focused on strengthening electricity infrastructure, improving market integration and increasing system flexibility.
ACER’s analysis covered countries most affected by the price spikes: Slovenia, Croatia, Hungary, Romania, Bulgaria and Greece. Austria and Slovakia were included as comparison markets reflecting central European electricity dynamics. The comparison was used to assess how regional conditions differed during the same period.
ACER identified limited system flexibility during evening peak-demand periods as a key driver of the electricity price surge. The report said this was especially relevant after solar power production declined. It also pointed to limited transmission capacity between countries, which reduced the region’s ability to import lower-cost electricity from other parts of Europe.
The agency added that planned maintenance works on transmission networks increased pressure by reducing cross-border electricity flows. It said these factors constrained how quickly regional systems could respond to changing demand and generation patterns. As a result, price outcomes were more sensitive to operational limitations.
While electricity prices became more stable in 2025 compared with the previous summer, ACER noted that differences between southeastern Europe and central Europe persisted into early 2026. This indicated that challenges extended beyond short-lived disruptions. ACER framed the issue as a longer-term market concern affecting the region’s performance.
In its conclusions, ACER said more efficient use of existing infrastructure could have reduced pressure during the crisis. At the same time, it stressed that expanding interconnection capacity alone would not address the problem without parallel investments in flexible resources and modern balancing technologies. The recommendations therefore combined network measures with operational and flexibility upgrades.
To improve market resilience, ACER recommended faster deployment of network-enhancing technologies, including advanced transmission equipment and dynamic line rating systems. The agency also called for stronger regional cooperation in managing electricity networks. It highlighted better coordination of maintenance schedules and broader use of corrective operational measures.
Additional proposals included accelerating strategic network investments across southeastern Europe. ACER also recommended removing barriers that prevent smaller market participants from entering the sector. It further supported technologies aimed at improving system flexibility and efficiency.
The report also emphasized continued efforts to integrate European electricity markets. ACER underlined maintaining cross-border transmission requirements, expanding flow-based market mechanisms and strengthening electricity market coupling with neighboring non-EU countries. The objective was a more stable and interconnected regional energy system through continued integration work.
