Coal, clean air, and a welcome resolution on India's emission norms

The changes to India's policy on emissions from coal plants are not a rollback - but a confident assertion of regulatory maturity, scientific integrity, and rational national interest

In a sweeping policy change, the Ministry of Environment, Forest and Climate Change (MoEF&CC) on July 11 recalibrated its 2015 mandate for flue gas desulphurisation (FGD) systems in coal-fired power plants. Backed by scientific studies and stakeholder consultations, this shift reflects the government’s commendable move towards region-specific, evidence-based regulation — balancing environmental priorities with India’s energy realities. 

This recalibration comes after decades of judicial and regulatory action on air pollution. The MC Mehta public interest litigation (1985), targeting Delhi’s air pollution, expanded to include emissions from thermal power plants (TPPs), prompting judicial and regulatory scrutiny. This led to the 2015 MoEF&CC notification mandating the installation of FGDs for all TPPs by 2017. Aimed at reducing sulphur dioxide (SO₂) emissions, the mandate tightened limits from 600 to 100 milligrams per normal cubic metre.  The directive triggered over 25 petitions from public and private power producers, citing high capital costs, technical constraints, and unclear cost recovery leading many to invoke “Change in Law” for tariff pass-through. Environmentalists petitioned the National Green Tribunal (NGT) for stricter enforcement. The NGT, in turn, directed the MoEF&CC to withhold environmental clearances for new TPPs unless they complied with the norms. In 2017, due to all these legal disputes, the lack of spare generation capacity, and the downtime required for retrofitting, the FGD deadline was extended to 2022 by the MoEF&CC. In 2020, the Association of Power Producers petitioned the Supreme Court (SC) for a blanket extension to 2024, which was rejected. Meanwhile, progress on FGD installations lagged significantly. 

In April 2021, the MoEF&CC released an amendment, superseding the 2015 notification for the third time, categorising TPPs into three groups: 

Category A: TPPs within 10 km of the National Capital Region or cities with populations over 1 million — deadline by December 2022. 

Category B: TPPs within 10 km radius of critically polluted areas/non-attainment cities — deadline by December 2023. 

Category C: All other TPPs — deadline by December 2024. 

In 2022, the Central Pollution Control Board (CPCB) extended the deadlines for Category A, B, and C TPPs to 2024, 2025, and 2026, respectively. In April 2025, the SC, reviewing compliance near Delhi, condemned repeated delays, rejected blanket extensions, and directed the government to issue legal notices to nine non-compliant plants. 

Meanwhile, a reassessment of India’s FGD policy was initiated, leading to the amendment of July 11. It retains the CPCB’s 2022 TPP categorisation but relaxes installation mandates and timelines. Of the 537 identified plants, only 65 Category A units must now install FGDs by December 31, 2027. For the 66 Category B plants, decisions will be made on a case-by-case basis, while the 406 Category C plants are exempt if they meet stack height norms. Importantly, SO₂ emission limits remain unchanged, in line with the original 2015 standards. 

India remains heavily reliant on domestic coal, which powers around 92 per cent of the country’s electricity generation — with no significant reductions projected in the medium term. According to a September 2024 report by the National Institute of Advanced Studies, the coal used in TPPs typically has a high ash content (35–45 per cent by weight) and low sulphur content (0.2–0.7 per cent). This is significantly lower than the sulphur content of US coal (1–1.8 per cent) and Chinese coal (over 1 per cent), classifying Indian coal as “very low sulphur coal.” 

A survey in May 2024 by IIT Delhi revealed that SO₂ levels in all surveyed cities — including those with coal-based TPPs lacking FGD units — remained within the National Ambient Air Quality Standards limit of 80 micrograms per cubic metre. The study found that acid rain is not a major concern in India due to the presence of alkaline dust and coastal sea breezes. 

India’s rollout of FGD installations has been sluggish. Out of the identified 537 TPPs for retrofitting, only 44 TPPs (central — 17, state — 8, private — 19) have completed installation.  With an estimated cost of ₹1.2 crore per Mw, total capital outlay could reach ₹96,000 crore. Many older TPPs struggle to justify such high investments. For consumers, FGD costs are “passed-through”, thereby raising electricity prices by ₹0.30–₹0.40 per unit. 

In sum, the July 2025 amendment is being widely appreciated by energy experts for four broad reasons: 

One, it acknowledges that SO₂ pollution from TPPs is less debilitating than previously feared. 

Two, it replaces a one-size-fits-all mandate with a tiered compliance framework. 

Three, consumers benefit from not having to pay a higher electricity tariff. 

Four, it saves substantial capital expenditure (both for central, state and private generators ), thereby freeing up scarce funding for greener, higher-impact investments that better serve India’s long-term sustainability goals. 

India’s decision also sends a clear message to the global community that it will not blindly adopt Western-style environmental mandates designed for high-sulphur coal contexts. Instead, it is embracing a region-specific, evidence-led strategy that balances air quality goals with climate and economic interests. 

Clearly, this is not a rollback — but a confident assertion of regulatory maturity, scientific integrity, and rational national interest. 

The author is an infrastructure expert. He is also the cofounder & managing trustee of The Infravision Foundation