CEPS: Fallen phase conductor caused Czech blackout, knocking out a transmission line and a power plant unit

The main mechanical cause of today’s widespread power outage in Czechia was the fall of a phase conductor, which carries electricity between power plants and substations. This subsequently knocked out a backbone high-voltage transmission line, one unit at the Ledvice power plant in the Teplice area, and the large Krasíkov substation in the Ústí nad Orlicí area. The transmission system operator ČEPS said this. The reason the conductor was damaged is not yet known.

Widespread power outages affected a large part of the Czech Republic around noon today. Parts of Prague, the Central Bohemian, Liberec and Ústí nad Labem regions, as well as eastern Bohemia, were among the areas left without power. At around 14:50, ČEPS announced that all substations were back in operation, and electricity supplies are gradually being restored across the country.

The phase conductor is a key component of the electricity system. According to energy industry experts, its failure can disconnect several substations and disrupt the stability of the entire grid. This was confirmed today. After the conductor fell, the V411 high-voltage transmission line also went out of service, ČEPS said. The line is used to evacuate large amounts of power from power plants and transmit electricity over long distances. According to the Novinky.cz website, ČEPS has been planning to modernise this line since 2016, with work due to begin next year.

Another consequence was the outage of the sixth unit at the Ledvice power plant. The V208 line, which connects substations, was also overloaded. The outage also affected the large Krasíkov substation in the Ústí nad Orlicí area. “This was followed by the separation of part of the transmission system, which could not be operated,” ČEPS said.

At 16:00, ČEPS also announced a state of emergency in connection with the response to the blackout, expected to last eight hours. However, it set the start of the state of emergency at 12:00 today. Under the Energy Act, a state of emergency allows exceptional events in the energy sector to be addressed more quickly.

Distributors are currently restoring electricity supplies gradually. At around 15:00, Pražská energetika said that most of Prague had power, and that reconnecting the remaining areas should not take long. ČEZ Distribuce is dealing with outages elsewhere and has also confirmed that supplies are being gradually restored across the regions.