In a significant shift aimed at balancing environmental goals with economic realities, the Ministry of Environment, Forest and Climate Change has revised the emission control norms applicable to coal-based thermal power stations. The new rules ease the requirement for installing flue gas desulphurisation (FGD) units—pollution control systems used to reduce sulphur dioxide (SO₂) emissions—across a large portion of India’s thermal power fleet.

Rather than a blanket mandate, the revised framework introduces a more selective, risk-based compliance structure. Now, only those plants located within 10 kilometres of cities with populations over one million will be required to install FGD systems. Plants in critically polluted areas or non-attainment cities will be considered individually, based on local air quality assessments.

This means that around 79 per cent of India's thermal generation capacity is now exempt from compulsory FGD retrofitting—a change driven by scientific studies and supported by cost-benefit analyses.

Why The Emission Norms Have Been Relaxed

The decision follows detailed research by institutions such as IIT Delhi, CSIR-NEERI, and the National Institute of Advanced Studies (NIAS), which found that SO₂ levels in much of India remain well below the National Ambient Air Quality Standards (NAAQS). With typical sulphur dioxide concentrations ranging from 3 to 20 µg/m³—far beneath the 80 µg/m³ NAAQS limit—the studies questioned the necessity of a universal approach to FGD deployment.

India’s domestic coal has low sulphur content, generally under 0.5 per cent. Combined with high stack emissions and favourable wind dispersion, the environmental impact of SO₂ emissions from most plants is already minimal, researchers said. Retrofitting every thermal unit with FGD was also expected to add an estimated 69 million tonnes of CO₂ emissions between 2025 and 2030 due to the additional limestone use, transport, and energy needed for the systems.

What This Means for Power Costs and Grid Reliability

The financial implications of the earlier FGD requirements had raised alarms within the industry. Power companies estimated a capital outlay of over Rs 2.5 lakh crore—equivalent to Rs 1.2 crore per MW. The retrofit process could take up to 45 days per unit, potentially affecting the electricity supply during peak demand periods.

The revised guidelines are expected to reduce power production costs by 25 to 30 paise per unit, a saving that could benefit both consumers and state distribution companies. Industry voices have largely welcomed the move. “This is a rational, science-based move that avoids unnecessary costs and focuses regulation where it is most needed,” a senior executive at a state-run utility remarked.

Officials clarified that the government remains committed to air quality goals but is choosing a more evidence-led path. “This is not a rollback. It is a recalibration based on evidence,” a senior official noted. “Our approach is now targeted, efficient and climate-conscious.”