NEW DELHI: The Commission for Air Quality Management (CAQM) on Friday said diesel generator (DG) sets of capacity up to 800 kilowatt can be permitted for industrial and commercial operations in Delhi-NCR from May 15 only after their conversion to the dual fuel system (gas and diesel). However, their operations will continue to be restricted during the Graded Response Action Plan (GRAP) period, it said. With effect from May 15, “any use of DG sets of capacity up to 800 kW shall be permitted for industrial and commercial sector in the entire NCR, only subject to their conversion to dual fuel system (70 per cent gas and 30 per cent diesel) in areas where gas infrastructure and supply is available”, the Centre’s air quality panel said in a statement. It observed that uncontrolled use of DG sets is a matter of concern. “A large number of DG sets operating in Delhi-NCR without adequate emission control measures, even during the periods other than the ban under GRAP, cause heavy air pollution and are thus a major contributing factor for deterioration of air quality in the region. “Therefore, regulating the use of DG sets even for the periods when there is no ban or restrictions imposed under GRAP is the need of the hour,” it said.