Islamabad, Pakistan – Authorities have restored electricity supply to parts of several main Pakistani cities and work on power restoration is continuing on Sunday after a major fault at a thermal power plant caused a countrywide blackout, plunging millions into darkness.
Power across the South Asian country of 220 million people was abruptly cut late on Saturday because of a fault at the Guddu thermal power plant, sending the entire country into darkness, Energy Minister Omar Ayub Khan said.
“At 11:41pm [18:41 GMT] the fault occurred at the Guddu power plant, and in one second the [power] frequency which is normally at 49.5 Hertz it dropped [to zero],” Khan told reporters in the capital, Islamabad.
“In technical terms, it is called a cascade [failures being caused], one after another. Power plant safety systems began to shut themselves down.”
Khan said a fault – as yet undiagnosed – at the 1,400MW thermal power plant caused the country’s entire electricity transmission system, which was handling 10,302MW at the time, to shut itself down.
Repair crews are continuing to diagnose the problem and parts of the system have been restored in the north of the country, he said.
“We started [the] Tarbela [hydroelectric power plant] twice – it synced and that allowed electricity to resume to several cities,” he said.
On Sunday morning, power had been restored to parts of the capital Islamabad, Rawalpindi, Faisalabad, Lahore, Multan, Jhang and Mianwali.
In Karachi, a sprawling metropolis of more than 20 million people and the country’s largest city, outages remained widespread as the city was receiving a fraction of its required power supply.
K-Electric, the electricity supply company in Karachi, said its crews were working on restoring power to all areas, and had successfully resumed supply to the city’s main water pumping stations.
The widespread blackout also caused travel disruptions, with several international airports across the country reporting problems.
As of Sunday morning, however, normal flight schedules appeared to have resumed.
The blackout is one of the worst in the country’s history.
The electricity infrastructure has received a great deal of investment in power generation capacity, but experts have long warned that significant problems remain in the transmission and distribution systems.
In 2015 the country experienced its last sweeping blackout when an attack by ethnic Baloch separatists on a major distribution line in the southwest of the country left more than 80 percent of the country without electricity.
While the increase in generation capacity in recent years has seen large-scale scheduled blackouts, which were once the norm, reduce in frequency, many Pakistani homes and businesses continue to maintain power backup systems, including diesel and gas-powered generators and battery-based uninterruptible power supply (UPS) systems, particularly in urban areas.
Pakistani authorities work to restore power after blackout The British Journal Editors and Wire Services/ Al Jazeera.