Electricity: Tripping power transmission grid lines in West Bengal and partially in Assam, India was the cause of the blackout yesterday and on Tuesday.

Most parts of western Bhutan, Phuentsholing, Paro and Thimphu were left in the darkness for more than an hour yesterday and for about 30 minutes on Wednesday night.

The transmission lines connected to the Chukha hydropower plant and Kurichhu hydropower plant were disturbed disrupting power connections in the dzongkhags.

Bhutan Power Corporation Limited (BPC) Managing Director Gem Tshering said that the corporation’s employees were working on restoring power lines and keeping the power on.

“We would like to apologise for the outage but we’ll make sure to restore it as soon as possible,” he said while Thimphu remained in darkness yesterday evening.

The outage yesterday occurred about 6:45pm yesterday. The power returned around after 8:20pm.

“The failure of the grid in the area pulled all our lines,” he said over telephone from Bumthang.

The western dzongkhags connected to Chukha hydropower plant also experienced similar outage the previous day around the same time. BPC officials attributed the same reason for the blackout.

The corporation exports power to neighbouring Indian states of Assam and West Bengal.

In both the incidences, the eastern region had uninterrupted power supply.

Tshering Palden