LAHORE: The impact of Saturday’s nationwide power breakdown persisted on Sunday as a number of rural and urban areas remained without power supply despite efforts by the field formations of the state-owned National Transmission and Despatch Company (NTDC).

The NTDC is responsible for power evacuation from plants and supplying to the distribution system of distribution companies (Discos) across the country.

Officials closely monitoring the situation believed that the Guddu power plant developed a technical fault minutes before midnight on Saturday that suddenly dropped the transmission frequency to zero and tripped the three main 500kV transmission lines that led to a cascading effect and further tripping of the other main lines and grids (220kV, 500kV, 132kV, 66kV and 33kV) across the country.

Reportedly, power supply to various urban and rural parts of major cities, including Faisalabad, Gujranwala, Kasur, and other districts in Punjab; Sukkur, interior Sindh districts of Dadu, Nawabshah and others; remote areas of Balochistan; and some in Khyber Pakhtunkhwa could not be restored by 7pm on Sunday.

Team probing into causes of fault at Guddu power station that caused blackout

However, it was restored to most areas of major cities in all provinces, including Karachi, Lahore, Islamabad, Peshawar, Quetta, Rawalpindi, Multan and Gujranwala, after the NTDC engineers succeeded in synchronising the transmission frequency with the distribution system.

“In Faisalabad, power supply to various urban localities such as Gulistan Colony, Sargodha Road, Razabad, Awami Colony and some others could not be restored till 8pm. Though, once electricity was restored at 10am, but later there was another blackout in various localities,” a local resident told Dawn. According to a resident of Gujranwala, electricity supply was restored to most of the city.

Similarly, power supply was restored to several parts of Kasur, including Pattoki, Kot Radha Kishan and Chunian tehsils, once around 10am. But, it was suspended again later. “The people felt a sigh of relief after power was restored to our area. But, that lasted only a couple of hours, as we again faced power suspension in our area,” a resident of Pattoki told Dawn. Some residents of Kasur, Chunian and Kot Radha Kishan too had similar ordeals to share.

A Sukkur resident reported complete restoration of electricity. But interior Sindh districts of Dadu, Nawabshah and some other areas (especially rural) remained blacked out till 8pm. “In some areas, the respective Discos (Sukkur Electric Power Company) intentionally avoided restoring power under a policy of not giving uninterrupted supply to the areas falling under service jurisdiction of the high loss feeders (category 3 onwards) -- the areas where people are involved in power theft the most,” an official explained. In Islamabad, too, power supply was again suspended to various parts due to technical reasons.

According to a senior NTDC official, who requested anonymity, the cause of the fault that developed at Guddu is yet to be determined by a high-level inquiry team.

“But it is confirmed that the fault first swiftly caused tripping of the 500kV Guddu-Muzaffargarh, Guddu-DG Khan and Guddu-Rahim Yar Khan lines that were carrying a load of up to 2,800 megawatts from the south to Punjab. That further led to tripping of the integrated system (500kV, 220kV and 132kV transmission and distribution lines and grids of NTDC and respective Discos) leaving almost the entire country into darkness,” the official told Dawn.

He said the drop in transmission frequency from 50 to zero had happened probably for the first time. “The team is critically reviewing all technical, administrative and functional factors and reasons,” he added.

Meanwhile, a spokesman for the NTDC claimed that power supply to most parts of the country was restored after synchronising the systems. “Guddu to Tando Muhammad Khan and NKI (Karachi) lines were energised, restoring electricity supply to Karachi and interior Sindh districts. Likewise, the Guddu to Muzaffargarh, DG Khan, Rahim Yar Khan and Bahawalpur lines have also been energised,” he explained, adding that the Jhimpir wind power cluster also resumed generation on Sunday.

The spokesman further said that power supply was restored to Peshawar, Islamabad, Jhelum, Gujrat, Sargodha, Sialkot, Faisalabad, Gujranwala, Lahore, Sheikhupura, Okara, Sahiwal, Rahim Yar Khan, Bahawalpur, Dahrki, Guddu, Rohri, Shikarpur, Dera Murad Jamali, Sibbi, Quetta (Industrial area), Dera Ghazi Khan, Muzaffargarh, Rahim Yar Khan and other cities gradually by 6pm on Sunday.

According to the Power Division of the federal energy ministry, the 132kV grids energised by 8pm in Lahore and surroundings included Shadman, Qartaba, McLeod Road, Gulshan-i-Ravi, Lahore Fort, Saidpur, Shamke, Saggian, Ravi, Bund Road, Badami Bagh, Sabzazar, Sheikhupura, Orient and Sapphire.

Likewise, the Kala Shah Kaku 220kV transmission line connected with all three circuits from Mangla was also energised. The Kala Shah Kaku-Bund Road 220kV line and grid station, Bund Road-Sheikhupura 220kV station and its two circuits, Kala Shah Kaku-Ravi Atlas 220kV station, eight out of the 12 220kV grid stations in Lahore and consumer-level 11kV power lines were also energised in Lahore.

“The teams also energised 500kV Rawat-Naukhar and 500kV Rawat-Tarbela lines,” said a power division spokesman.

Published in Dawn, January 11th, 2021