The Expert Panel established to investigate the blackout that occurred on 18 May 2025 in North Macedonia is publishing its final report today. The report identifies the causes of the blackout and outlines recommendations to strengthen the resilience of Europe’s interconnected electricity system. It was prepared by an 18-member Panel comprising representatives from Transmission System Operators (TSOs), ACER, and National Regulatory Authorities (NRAs). The Panel was chaired by an expert from 50Hertz, a TSO outside the affected area.
The investigation concluded that the blackout in North Macedonia resulted from operating the transmission system above the defined voltage limits of 420 kV. This overvoltage led to the tripping of all 400/110 kV transformers, resulting in the 400 kV network being separated from the 110 kV network and causing the blackout in the region.
Based on these causes, the Expert Panel has set out recommendations addressing each of the factors identified in the report, with the aim of preventing similar events in the future. These include a recommendation to establish an action plan for the entire South-East Europe (SEE) region to mitigate high-voltage conditions, as well as a recommendation for stronger alignment among TSOs on operational voltage control measures, supported by RCCs and ENTSO-E.
Read the full report here.
About ENTSO-E
ENTSO-E, the European Network of Transmission System Operators for Electricity, is the association for the cooperation of the European transmission system operators (TSOs).
The 40 member TSOs, representing 36 countries, are responsible for the secure and coordinated operation of Europe’s electricity system, the largest interconnected electrical grid in the world.
Press contact: media@entsoe.eu