Context
- The Environment Ministry has exempted 78% of India’s coal-based thermal power plants from installing Flue Gas Desulphurisation (FGD) systems that control Sulphur Dioxide (SO2) emissions.
- These systems were earlier mandated in 2015 to control SO2, which contributes significantly to air pollution.
Relevance : GS 3(Environment and Ecology)
Why are SO2 emissions from coal plants a concern?
- SO2 reacts with ammonia (NH3) to form ammonium sulfate, which contributes to PM2.5 pollution—affecting lungs and cardiovascular health.
- PM2.5 exposure is linked to asthma, bronchitis, heart attacks, and premature deaths.
- CREA data: 52% of SO2 emissions in India come from coal plants; in 2023, SO2 levels rose compared to 2019, especially near coal-dense regions.
Original plan for pollution control
- 2015: Centre introduced emission norms for SO2 and other pollutants from coal plants; FGD installation was required by 2017.
- Deadline extended four times due to:
- High costs of FGD devices
- Risk of electricity shortages due to plant shutdowns for retrofitting
Current classification of plants
Power plants divided into 3 categories (2021 update):
- Category A: Within 10 km of the National Capital Region or non-attainment cities → deadline: Dec 2022
- Category B: Located in populous areas with frequent air violations → deadline: Dec 2023
- Category C: Other remaining plants → deadline: Dec 2024
78% of all coal plants fall under Category C and are now exempted from installing FGDs.
Why this relaxation now?
- Based on studies by:
- IIT-Delhi
- IIT-Madras
- NEERI
- These studies argue:
- SO2 emissions from most plants are within permissible limits
- Focus should be on overall particulate matter pollution, not just SO2
Economic argument
- FGDs are expensive and energy-intensive.
- Fears that retrofitting would increase power tariffs, affecting electricity affordability.
- Plants shutting down for installation could create power supply disruptions.
Criticism & Counterviews
- CREA and CSE question validity of studies:
- Studies don’t track downwind SO2 dispersal.
- SO2 plumes can travel 300+ km, converting to secondary pollutants mid-air.
- NEERI’s findings were reportedly commissioned by NITI Aayog, raising concerns of bias.
- Centre for Science and Environment (CSE) says:
- Real-world atmospheric SO2 remains high around plants.
- FGDs are necessary to prevent long-term cumulative exposure.
Implications
- Environment: Signals diluted commitment to clean air goals under NCAP.
- Health: May undermine public health protection, especially in coal belt regions.
- Governance: Reflects tension between environment regulation and power sector realities.
- SDGs: Potential setback to SDG 3 (Health), SDG 7 (Clean Energy), and SDG 13 (Climate Action).
