India, July 13 -- The union environment ministry has issued a notification once again extending the timelines for thermal power plants to comply with sulphur dioxide (SO2) emission standards. According to expert analysis, the notification also effectively exempts a large proportion of thermal power plants-representing more than 75% of India's thermal power capacity-from complying with SO2 norms, provided they ensure compliance with stack height regulations.

Addressing SO2 emissions is critical due to their contribution to secondary particulate emissions. The new notification, issued on July 11, introduces a revised compliance mechanism for SO2 norms applicable to coal- and lignite-based thermal power plants. It categorises these plants i...