Calcutta and Howrah suffered prolonged power cuts on Thursday, after a drastic drop in supply from the state electricity board grid to the CESC system. Officials blamed a series of transmission faults and the shutdown of a 210-mw generating unit at the state-run Kolaghat plant.
The deficit in the CESC areas shot up to 127 mw in the evening peak hour. In the districts, particularly Hooghly and Howrah, the deficit crossed 400 mw. Power cuts in the city ranged from two to three hours, and in the districts, from four to five hours. Power department sources ruled out an improvement on Friday.
SEB sources said that severe lightning and heavy rain in Howrah and Hooghly led to the tripping of two 220-KV transmission lines between Howrah and Kolaghat and another between Rishra and Liluah.
These lines transmit the power generated by the Kolaghat plant. So, the authorities were forced to shut down the first unit of the plant, bringing down generation by 210 mw.
The situation was compounded by Wednesday’s breakdown of a 210-mw unit at the Bandel power plant. The tube leak that shut it down is yet to be repaired.
“The transmission collapse, coupled with the absence of two major generating units, forced us to cut supply to the CESC grid to 100 mw in the evening peak hour,” said an SEB official.
SEB engineers have identified the snags in the transmission lines and repairs are being carried out on an emergency basis. “But the repairs will take time,” an official said.