Implementation of SO2 Norms for Coal-based Thermal Power Plants

Background and Concerns

• In 2015, the Union Ministry of Environment, Forest and Climate Change introduced SO2 norms for coal-based thermal power plants.
• Mandatory installation of flue gas desulphurisation (FGD) systems was required for over 600 power plants in India.

Financial and Technical Implications

• Estimated capital expenditure on FGDs was expected to increase tariffs by Rs 0.25 – 0.30 per KWhr.
• The financial burden would impact power generators, distribution companies, and consumers.
• Experts questioned the technical necessity of FGDs given the low sulphur content in Indian coal, necessitating further research.

Research and Analysis

• A study by IIT Delhi highlighted the need for a more comprehensive analysis of SO2 emissions.
• Niti Aayog's study by NEERI found ambient SO2 levels were below prescribed norms, even without FGDs in many plants.
• Recommendations suggested revisiting SO2 emission norms, considering India's unique solar insolation and atmospheric conditions.

Environmental and Economic Considerations

• FGD systems require limestone and water, adding a significant carbon footprint due to limestone mining and transport.
• The atmospheric lifetime of CO2 exceeds that of SO2, presenting a climate concern.

Revised Notification and Future Implications

• The revised notification classifies power plants based on proximity to large cities and pollution levels.
• Approximately 78% of power plants do not need FGD systems, allowing significant savings in capital expenditure for renewable energy development.
• The notification mitigates tariff burdens on consumers and supports clarity in planning for domestic coal-based power.

Conclusion

• Renewable energy will play a crucial role in India’s long-term energy transition, but coal will remain important for energy security.
• The changes provide consumers and planners with relief and clear guidance for future energy infrastructure development.