The Ministry of Environment and Forests announced a major policy update on 14 July 2025. It exempted most thermal power plants from installing flue gas desulphurisation (FGD) units. This move aims to provide a more targeted and cost-effective approach to reducing sulphur dioxide emissions. The Ministry clarified that this is not a rollback of environmental safeguards but a scientifically justified shift aligned with climate goals.
Background of FGD Mandate
In 2015, India mandated all coal-based thermal power plants to install FGD units. These systems reduce sulphur dioxide emissions, a key pollutant causing acid rain and respiratory issues. Despite this, only about 8% of India’s 180 coal plants installed FGDs due to high costs and limited availability. Multiple extensions were granted to plants unable to comply.
Current Policy Changes
The new regulation requires only 22% of plants, mainly in major cities with poor air quality, to install FGDs. Plants are classified into three categories – – Category A – Units within 10 km of cities with over one million people or the National Capital Region must install FGDs by 30 December 2027. – Category B – Units near Critically Polluted Areas (CPAs) or Non-Attainment Cities (NACs) may install FGDs based on Expert Appraisal Committee decisions, with a deadline of 30 December 2028. – Category C – The remaining 78% are exempt from FGD installation.
Scientific and Economic Rationale
India’s ambient sulphur dioxide levels have declined . A 2023 survey of 492 cities showed only two cities—Dehradun and Kolar—exceeded the national standard of 50 micrograms per cubic metre. This standard is stricter than those in Japan, the European Union, and Australia. Indian coal naturally contains low sulphur (about 0.5%), resulting in lower sulphur dioxide emissions despite high ash content. Studies found no difference in sulphur dioxide levels between cities with and without FGDs. The Ministry pointed out that eliminating all sulphur dioxide emissions would only marginally improve particulate matter (PM2.5) levels, which are the main cause of health problems. The cost of installing FGDs is very high—₹1.2 crore per megawatt—totaling ₹2.54 lakh crore nationally, with minimal air quality benefits.
Environmental and Regulatory Context
Critically Polluted Areas (CPAs) are industrial regions with severe pollution, identified by the Central Pollution Control Board. Non-Attainment Cities (NACs) are urban areas failing to meet National Ambient Air Quality Standards for over five years. The Expert Appraisal Committee evaluates the need for FGDs in Category B plants, ensuring environmental clearances align with local pollution levels.
Impact on Thermal Power Sector
The revised rules reduce the regulatory burden on most thermal plants. Only about 11% of the 600 thermal power units must install FGDs mandatorily. This allows resources to be focused on regions with the greatest pollution challenges. The extensions provide time for compliance without disrupting power supply.
Questions for UPSC:
- Critically discuss the role of flue gas desulphurisation technology in controlling air pollution and its economic implications for India’s thermal power sector.
- Analyse the impact of ambient air quality standards on environmental policy formulation in India and compare them with international standards.
- Examine the challenges in balancing industrial growth and environmental sustainability in India’s energy sector and suggest viable policy measures.
- Point out the significance of categorising regions as Critically Polluted Areas and Non-Attainment Cities and estimate their impact on urban health and regulatory practices.
