ČEPS: Multiple outages caused Czech blackout; reason for their coincidence remains unclear

Friday’s widespread power outage in part of Czechia was caused by several outages occurring at the same time, but the reason for this coincidence remains unclear. ČEPS Chairman Martin Durčák said this at a press conference today. He ruled out grid overload caused by power flows or damage by a third party, saying the system had been operating reliably before the outage. The line whose failure led to the blackout was damaged last year, but that did not cause any further outages at the time. Today, ČEPS launched extraordinary inspections of key power lines using thermal imaging and is also planning further specialised inspections. It expects to have the results within a matter of weeks.

A large part of Czechia was hit by a massive power outage on Friday that lasted several hours and was caused by a broken cable. According to Industry and Trade Minister Lukáš Vlček (STAN), around one million customers were left without electricity. There are 6.3 million points of consumption in the country.

According to ČEPS, the main mechanical cause was the rupture of a phase conductor, the cable that carries electricity between power plants and substations. This knocked out backbone line V411, which is used to evacuate high power output from power plants and transmit electricity over long distances. The Ledvice power plant unit in the Teplice region and the large Krasíkov substation in the Ústí nad Orlicí region then went offline. Because of the heavy load, the dispatcher also switched off line V208, which connects substations.

“If other parts of the system had not failed at almost the same time, the outage of line V411 would not have taken the system outside the permitted operating limits,” Durčák said.

Under normal circumstances, he said, a cable rupture on the line would not have led to further outages. He noted that line V411 had also failed in November last year, but no other equipment went offline as a result at the time. ČEPS subsequently repaired the line.

ČEPS is now investigating the connection between the individual outages together with distributors and other experts. It expects to have the results within a matter of weeks. In parallel, the company launched special inspections of key lines this morning, checking their condition and operation using thermal imaging from a helicopter.

Durčák also ruled out the possibility that Friday’s blackout was caused by grid overload due to electricity flowing in from abroad. According to ČEPS statistics, electricity imports from Germany were slightly above the original plan, but the company said they remained within standard values. “Power flows are often significantly higher, and the system has no problem with that,” said ČEPS Vice-Chairman Svatopluk Vnouček.

Andrej Babiš, chairman of the opposition ANO movement, has said that grid overload caused the outage. He said it resulted from the failure to manage electricity flows from Poland and Germany generated by solar and wind power. One of the four large transformers installed near Kadaň to curb these flows has also been out of operation since last November, he said in a video on Facebook. The government and ČEPS, he said, are being evasive about the outage.