Electricity-starved citizens who dialled the CESC helpline on Friday to find out when their agony would end were told that an hour’s power cut every four hours would continue for some time.

The ominous message came on a day when the city and the suburbs spent long periods without power, the muggy weather doing little to ease their discomfort. The shortfall in CESC areas during evening peak hours was 65 MW, which officials said was better than Thursday’s record.

The power pinch will probably be felt even more from Saturday, when a 210-MW unit of the Kolaghat station will be shut down for annual maintenance.

On Thursday, power cuts were reported almost everywhere in the city after one of the two 250-MW units at CESC’s Budge Budge plant was shut down to repair a snag in the boiler tube. The unit resumed functioning on Friday afternoon and power generation increased as the evening progressed.

The 65-MW shortfall, however, ensured that almost every locality went without power for an hour on an average. “Had the Budge Budge unit not been functioning by evening, we would have recorded a higher shortfall,” a CESC official said.

On Thursday evening, Calcutta and its adjoining areas were short of 195 MW.

The frequency of power cuts increased after coal supplies to Kolaghat and Bakreswar, the electricity mainstays of the city, declined because of monsoon rain across Gangetic Bengal and Jharkhand.

Now, with one the six 210-MW units at Kolaghat about to be closed for an overhaul, officials fear it’s going to get worse.

“We would have shut down the unit on Thursday itself, but did not do so because CESC’s Budge Budge unit was not up and running. Now that the Budge Budge unit is back, we will have to shut down the Kolaghat unit on Saturday night. The overhaul is long overdue,” said S. Mahapatra, the managing director of the West Bengal Power Development Corporation Limited.

The six units in Kolaghat generated only about 900 MW on Friday evening, against their installed capacity of 1,260 MW. The three units in Bakreswar generated 470 MW, which is about 160 MW less than their combined capacity.

Officials of the power development corporation said all units should be in top shape by September, when commercial demand increases because of puja shopping.

Till then, bear with a power cut every four hours.