Cash-strapped Karachi Electric Supply Corporation (KESC) plans to witch its power generation units of Bin Qasim Thermal Power Plant and Korangi Thermal Power Plant 12 gas from furnace oil to save at least Rs 145 million per month, sources told PPI on Monday. The total offtake of furnace oil by the KESC for power generation ranges from 4,000 to 4,500 tonnes per day. It would need around 250 mmcf per day gas to run its plants. The switch-over would not need any fresh investment by the KESC as the existing plants are capable of using both furnace oil and gas as fuel.