As of September 2024, India has an installed electricity generation capacity of 452 GW. Coal-fired power plants (CFPPs) hold the largest share of this capacity, with 211 GW (47%), followed by renewable energy sources at 34%, hydro at 10%, gas at 5%, nuclear at 2%, lignite at 1%, and diesel at less than 1%.

Although CFPPs account for less than half of installed capacity, they meet over 70% of India’s power demand. The Central Electricity Authority (CEA) recently projected in its optimal generation capacity mix report that CFPPs will continue to play a dominant role in 2029-30, with a minimum addition of 80 GW in thermal capacity anticipated. While installed capacity is expected to rise, coal consumption is projected to increase from 749 million tonnes in 2022-23 to 1,019 million tonnes by 2029-30. This increase reflects the ongoing reliance on coal despite efforts to diversify energy sources.

Sulphur dioxide (SO₂) is a significant air pollutant with direct and indirect effects on human health, the environment, and climate that is primarily emitted from burning fossil fuels, particularly coal, in CFPPs.

SO₂ is a precursor to the formation of fine particulate matter (PM_2.5), which has been linked to severe health issues, including respiratory and cardiovascular diseases. Exposure to high levels of SO₂ can irritate the eyes, throat, and lungs, aggravating conditions such as asthma and bronchitis. Long-term exposure is associated with an increased risk of heart attacks, strokes, and premature death. Moreover, SO₂ contributes to the formation of acid rain, which can damage ecosystems, and harm aquatic life.

In 2022, India was the largest emitter of SO₂ globally, accounting for over 20% of the world’s anthropogenic emissions, primarily due to its heavy reliance on coal for electricity generation.

India has the highest SO₂ emissions from electricity generation, at 6,807 kilotonnes, followed by Turkey (2,206 kilotonnes) and Indonesia (2,017 kilotonnes). Other significant emitters include South Africa (1,705 kilotonnes), and Saudi Arabia (1,181 kilotonnes).

Indeed, five of the top ten SO₂ emission hotspots from coal and power generation are located in India, particularly in the densely populated Indo-Gangetic Plains, home to numerous CFPPs, and according to CREA’s satellite data analysis, the highest atmospheric SO₂ levels in India are found in areas with larger numbers of CFPPs.

Despite the significant health and environmental impact of CFPP emissions, regulatory enforcement on these power plants remains far less stringent compared to the seasonal restrictions and penalties imposed on stubble burning. During the stubble burning season, farmers face heavy fines and rigorous monitoring, with strict enforcement of pollution control measures. In contrast, CFPPs are often granted leniency, with delays in implementing necessary technologies like FGD and repeated extensions for compliance.

According to CREA’s analysis based on a recent Central Electricity Authority (CEA) report, only less than 8% of the total CFPP electricity generation capacity has installed flue gas desulphurization (FGD) to control SO₂ emissions. Since 2019, progress on installing FGD has been slower than anticipated, with delays evident across multiple stages.

Examining the bottom-up data for emissions after installing FGD systems, the potential reduction percentages highlight the encouraging trends. At a national level, the installation of FGD systems could reduce SO₂ emissions significantly, from a total of 4,327 kilotonnes to 1,547 kilotonnes. This amounts to an overall reduction of approximately 64%, highlighting the tremendous potential impact of FGD technology on reducing air pollution from CFPPs.

The adoption of FGD technology has led to a notable reduction in SO₂ emissions across all sectors. Post-FGD implementation, emissions have dropped to 500 kilotonnes for the state sector, 420 kilotonnes for the central, and 627 kilotonnes for the private sector. This translates to reductions of 65%, 69%, and 60% in the state, central, and private sectors respectively. Notably, the central sector shows the highest percentage reduction, suggesting it has the highest potential for improvement when equipped with pollution control technology. However, the private sector, even after FGD installation, remains the largest emitter, indicating further measures could be explored to enhance emission control in this sector.

Key findings

• Satellite data analysis shows an increase in sulphur dioxide (SO₂) levels in India in 2023 compared to 2019, with a notable rise in regions dominated by coal-fired power plants (CFPPs), highlighting the influence of power plant emissions on air quality.
• According to our bottom-up estimates, 4,327 kilotonnes of SO₂ were released by 537 CFPP units from June 2022 to May 2023, with the state sector contributing the largest share at 1,563 tons, accounting for approximately 36% of the total emissions. The central sector follows with 1,426 kilotonnes, making up about 33% of the emissions, while the private sector contributes 1,339 kilotonnes or 31%.
• Particulate matter emissions were also quantified and amounts to 277 kilotonnes from all CFPPs. The sector-wise breakdown of current particulate matter emissions indicates contributions of 78 kilotonnes from the central sector, 123 kilotonnes from the state sector and 76 kilotonnes from the private sector.
• CFPPs in India emitted over 10 times and 240 times higher, respectively than the 26.7 kilotonnes of particulate matter and 17.8 kilotonnes of SO₂ released from burning 8.9 million tonnes of paddy straw.
• Less than 8% of CFPP capacity has completed flue gas desulphurization (FGD) installation to control SO₂ emissions. Although bids have been awarded for nearly half the capacity, progress stalls due to a lack of punitive measures, escalating costs, and repeated deadline extensions.
• Adopting FGD technology would lead to a notable reduction in SO₂ emissions across all sectors. Post-FGD implementation, emissions have dropped to 500 kilotonnes for the state sector, 420 kilotonnes for the central, and 627 kilotonnes for the private sector. This translates to emission reductions of 65%, 69%, and 60% in the state, central, and private sectors respectively.

To address the escalating SO₂ levels and protect public health, CREA urges immediate action through:

1. Enforceable deadlines: Setting binding timelines for FGD installations across all sectors.
2. Strict regulatory measures: Penalties for delays to ensure compliance with installation targets.
3. Transparency and accountability: Publishing regular updates on FGD progress and emission reductions to encourage accountability.

Methodology SO2 emissions from 537 CFPP units were calculated using a bottom-up approach, incorporating four key parameters: coal consumption, stack emissions, flue gas flow, and the gross calorific value of coal.  Monthly coal consumption data for CFPPs is published by the CEA. Since this study aims to estimate emissions at the unit level, unit-wise average energy generation data from the National Power Portal was used to calculate unit-level coal consumption. Initially, the total plant generation was calculated by summing unit-level generation data.  The full methodology is available in the report.