On Thursday, a large part of Prague was hit by a severe power outage caused by a technical failure in a substation. ČEPS, which operates the electricity transmission system in the Czech Republic, did not supply electricity to the PRE company, which provides electricity for households and companies in the capital. The outage affected about 200,000 users in the city center and other parts of Prague, with all power supplies restored in less than an hour.
According to ČEPS, the failure occurred due to gas pressure issues, which caused the substation to shut down.
“This automation protects the equipment in the event of a drop or loss of insulating gas, thus preventing electrical equipment from malfunctioning. Specific technical causes are now being investigated,” said Lukáš Hrabal from the company’s press department.
Across nearly half of Prague, trams did not operate for about an hour, and one of the three subway lines was not working for nine minutes. Although electricity generators were switched on in the metro, they only serve to get the trains to the nearest station so that passengers can get out of the metro safely. The outage also severely limited train traffic.
In connection with the blackout, firefighters announced rescue operations in several parts of the capital, especially for people stuck in elevators. First responders also aided two patients at home whose oxygen machines stopped working. Hospitals hit by power outages relied on backup generators.
The interruption of electricity supplies additionally caused outages of some internet networks, and the public media website of Czech Radio and Czech Television stopped working completely.
The Chodov power substation, where the failure occurred, has been in operation since 1997. Three years ago, ČEPS invested 300 million korunas (€12 million) in a reconstruction and capacity expansion. Problems with electricity supply in Prague have arisen in this substation in the past, including from a fire that broke out in 2013, which caused a blackout of a similar magnitude as the one that struck yesterday.
Electricity is supplied to the capital city of Prague mainly from three substations, which are interconnected. If one fails, electricity can be replaced from the remaining substations. However, if more than one substation fails at once, according to former Prague Mayor Tomáš Hudeček, a big problem will arise.
“Such a situation would be tough,” Hudeček said in an interview with the iDNES.cz news outlet. “Two substations will step in. If another fails, it is impossible to bring enough current from elsewhere, and a crisis scenario is set. Large customers will be cut off from the power,” he added.
“Blackout is a threat mainly to urban areas. When someone in a rural home loses electricity, the owner is knowledgeable enough to deal with the situation. When the same happens in a skyscraper, where everything, including air conditioning, heating, and hot water, is dependent on electricity, a big problem arises. There is no point in being frightened about every outage. Our society should be able to handle a similar situation. But in cities, it can lead to a fight for basic life,” said Hudeček.