• ACER and national regulators join ENTSO-E’s Expert Panel investigating the incident which led to the loss of around 3,300 MW of generation capacity
  • No impact on consumers nor on the operation of the synchronously interconnected power system of Continental Europe.
  • The Expert Panel will identify the causes and make recommendations in a Final Report.

An incident which took place in Poland’s Rogowiec substation on the 17 May 2021 led to the tripping of ten generation units of the Bełchatów power plant and a loss of 3,322 MW of generation capacity.

No consumer was disconnected. There was no negative impact on the operation of the synchronously interconnected power system of Continental Europe. Thanks to the swift remedial actions taken by PSE, the Polish Transmission System Operator (TSO), as well as the emergency support from neighbouring TSOs and cooperation with the coordination centre, the power system was operating again within the security limits approximately 20 minutes after the incident. The Rogowiec substation returned to normal operation about one hour after the incident and the tripped generation units of the Bełchatów power plant were re-connected to the power system as soon as technically possible.

Based on preliminary data, this incident is classified as a scale 2 incident as per the legally-mandated Incident Classification Scale (ICS). For scale 2 incidents, the ICS Methodology foresees that a final report shall be prepared by an Expert Panel. ENTSO-E has set up the Expert Panel composed of representatives of transmission system operators and has invited ACER and relevant NRAs to join it.

Expert Panel’s Final Report expected in Quarter 1 2022

The Expert Panel will prepare a Final Report, which shall describe the sequence of events and details of the incident. It will also explain the causes and contain recommendations to prevent such incidents in the future. The Expert Panel’s Final Report shall be published in the first quarter of 2022.

ACER and ENTSO-E will continue together to publish information about the incident on their websites.



  1. Incident Classification Scale. The ICS Methodology has been developed in accordance with Regulation (EU) 2019/943 of the European Parliament and of the Council of 5 June 2019. It was updated in 2019, to fulfil the objectives of Article 15 of SO GL quoted above.
  2. Commission Regulation (EU) 2017/1485 of 2 August 2017 establishing a guideline on electricity transmission system operation (System Operation Guideline, SO GL).

Press contacts:

ACER, una.shortall@acer.europa.eu, T: + 32 (0) 484 66 85 99

ENTSO-E, claire.camus@entsoe.eu, T: +32 (0) 476 97 50 93.