Darkness engulfed the city and its adjoining areas on Saturday evening after a giant 210-MW unit collapsed at the state-run Kolaghat thermal power plant.
The breakdown forced the State Electricity Board (SEB) to slash supply to the CESC grid to a meagre 50 MW. As a result, the shortfall in the CESC-served areas shot up to 200 MW around 6.30 pm. The situation was worse in the districts as the deficit rose to 450 MW.
Sources in the power department said generation at Kolaghat dropped sharply when a tube in one of its units started leaking. “We were forced to cut down on the supply to the CESC grid by about 200 MW. Or else, the shortfall in the districts served by the SEB would have shot up to around 650 MW,” said an SEB official.
Hit by the sudden restriction in supply from the SEB, the CESC resorted to rotational power cuts across the city, ranging from 45 minutes to two hours. The private power utility’s units generated about 1,000 MW, sources added.
SEB sources said the situation is likely to improve by Sunday when the crippled Kolaghat unit is brought back in operation.
The Kolaghat plant, said sources, had been failing to generate its installed capacity of 1,260 MW for several weeks. The plant suffered a setback around 10 days ago after a major breach in its ash pond led to large quantities of flyash spilling over to the adjoining areas.
Following protests from the neighbouring villages, the Kolaghat authorities were forced to shut down a unit and bring down the generation of two other units to check the flyash spillover.