New Delhi: Nearly 81% of sulphur dioxide (SO₂) emissions from coal fired power plants within a 300-kilometre radius of Delhi NCR originate from plants that are no longer required to install pollution control systems, according to a new analysis by the Centre for Research on Energy and Clean Air (CREA).
The findings come one year after the Union Ministry of Environment, Forest and Climate Change relaxed emission norms for most coal fired power plants, exempting 78% of India’s coal plants from installing flue gas desulphurisation (FGD) systems, which can reduce SO₂ emissions by up to 95%.
CREA analysed 12 coal-fired power plants comprising 37 generating units around Delhi-NCR. Based on publicly available data from 25 units, the study estimates that these plants will emit around 154 kilotonnes of SO₂ in 2025, with nearly 90% of emissions coming from units operating without FGD systems. Category C plants, which are exempt from mandatory FGD installation, account for the majority of these emissions.
The report warns that the issue could worsen as coal-based electricity generation is expected to increase under a strong El Niño scenario, with higher electricity demand and lower hydropower generation likely to boost coal consumption.
Sulphur dioxide is a major precursor to fine particulate matter (PM2.5), which is linked to respiratory illnesses, cardiovascular diseases, stroke and premature deaths. CREA cited a recent peer reviewed study showing that the energy sector contributes up to 16% of particulate pollution in Delhi-NCR cities.
The analysis also found a sharp contrast between plants with and without pollution controls. The Mahatma Gandhi Thermal Power Plant, equipped with FGD systems, emitted around 1,775 tonnes and 2,154 tonnes of SO₂ from its two units. In comparison, the Rajpura Thermal Power Plant, which lacks effective SO₂ controls, emitted an estimated 20,851 tonnes and 22,690 tonnes, making it the highest emitter in the assessment.
CREA has recommended reinstating mandatory FGD installation for all coal-fired power plants, making real-time emissions monitoring data publicly available, and regularly disclosing the operational status of FGD systems. The organisation said these measures would help reduce SO₂ and PM2.5 pollution, strengthen compliance with emission standards, and improve public health as India’s dependence on coal-based power continues to grow.