Most NCR thermal power plants exceed MOEFCC emission norms, adding to region’s pollution problem

Recent CSE analysis found just two of 11 plants have SO2 control measures, just one compliant with standards

By Anubha Aggarwal
Published: Tuesday 28 November 2023
Photo for representation: iStock__

Only two out of the 11 plants in the National Capital Region have sulphur dioxide (SO2) control measures in place and only one of these two plants is actually complying with the standards, according to a recent analysis by Delhi-based think tank Centre for Science and Environment. 

The analysis is based on the plants’ environmental status reports from April 2022 to August 2023 submitted to the Central Electricity Authority (CEA), the technical arm of the Union Ministry of Power. 

The analysis found emissions from most plants in the NCR exceeded the norms that were first introduced by the Union Ministry of Environment, Forest and Climate Change (MoEFCC) in 2015. 

All power plants were instructed to comply with the norms by December 2017, however, due to a lack of technical capabilities and regulatory foresight, the deadlines had to be extended by another five years for all plants except the ones in the NCR. 

Given the high levels of pollution in the area, the MoEFCC accepted a deadline of December 2019 for plants in Delhi. However, all plants — except Mahatma Gandhi Thermal Power Plant (TPP) and Dadri TPP — failed to meet the emission standards and continued operations through March 2021 without any regulatory action against them. 

In March 2021, all power plants were classified into three categories based on the criteria determined by the Central Pollution Control Board (CPCB), with different deadlines. Based on this criteria, only three of the 11 plants were placed in Category A — which were told to comply first — and the rest were in Category C — which were to comply last. In September 2022, these deadlines were revised once again. 

Classification of coal TPPs under three categories


Plants in Delhi-NCR

Parameters other than SO2 norms 

SO2 emissions 

A: Within 10 km radius of the National Capital Region of cities with million plus population

Dadri TPP, Indira Gandhi TPP, Mahatma Gandhi TPP and Panipat TPP

December 31, 2022

December 31, 2024

B: Within 10 km radius of critically polluted areas or non-attainment cities


December 31, 2023

December 31, 2025

C: Remaining plants

Harduaganj Thermal Power Station, Guru Gobind Singh TPP, Guru Hargobind TPP, Talwandi Sabo TPP, Rajiv Gandhi TPP, Yamunanagar TPP, Rajpura TPP

December 31, 2024

December 31, 2026

Source: MoEFCC

Emissions by coal-based TPPs higher than standards

The CSE analysis finds that because of the multiple extensions in the deadline, the plants may not be in violation of the norms, but their emissions, especially for SO2, are much higher than the prescribed limits. All plants except one — Mahatma Gandhi TPP — have reported SO2 emissions three times that of the norm in the reporting period. 

SO2 is a reactive gas and converts to sulphates in the form of fine particulate matter (PM) 2.5, which pose even greater risk to health and environment. 

Apart from SO2 emissions, nitrogen oxides (NOx) emissions were exceeded by four plants — Panipat Thermal Power Station (TPS), Rajiv Gandhi TPP and Yamunanagar TPP in Haryana and Guru Hargobind TPP (Lehra Mohabbat) in Punjab — several times in the reporting period. 

“The plants should be able to meet the NOx norms, especially when it has now been diluted, with proper operational intelligence and with the assistance of the Original Equipment Manufacturers (OEM) to carry out necessary modifications in the plant boilers,” said Ashu Gupta, ex-general manager, NTPC (formerly National Thermal Power Corporation). 

Similarly, three plants in the NCR — Harduaganj TPS of UPRVUNL, Panipat TPP of Haryana Power Generation Corporation Ltd and Guru Hargobind TPP (Lehra Mohabbat) of Punjab State Power Corporation Ltd — have still reported very high suspended particulate matter (SPM) emissions. 

Minor changes in operational parameters and regular maintenance of electrostatic precipitators can make substantial improvement in compliance for power plants where SPM norms are not being met continuously.

Gaps in monitoring data

Until recently, compliance with the emission norms had become synonymous with the integration of flue-gas desulphurisation (FGD) — a SO2 control device — with the stacks / chimneys of TPP. This was because there was no information available regarding any of the other parametres — NOx and SPM — in the public domain. 

The CEA’s decision to share the environmental status of coal thermal power plants on their website is commendable; however, this data will be meaningless if the plants only report emissions intermittently. Four out of 11 plants have submitted less than 60 per cent data during the reporting period. 

Furthermore, despite massive investments made by power plants in installing continuous emission monitoring systems to relay data to the CPCB, the data is still kept confidential. CPCB should make online emission monitoring data available to the public and publish its analysis of the emissions from these plants. 

Given the exigency of the situation, CSE has advocated prioritising emission norms compliance by coal-based power plants in the NCR.  

Delhi-NCR cannot meet the clean air benchmark and protect public health if continuous sources of pollution like thermal power plants remain high emitters, according to Anumita Roychowdhary, executive director, research and advocacy, CSE

These plants have not been able to meet the standards and are at varying stages of progress simply because the target dates for compliance are shifting continually. Instead of delaying the timeline, focus more on the enablers in terms of strong compliance and deterrence mechanisms, as well as incentives and one-time support for fast-tracking change and time-bound implementation. This is a critical regional strategy for the cleaning up of the airshed,” Roychowdhary said. 

“We cannot deny our growing energy needs and the operational issues with regard to shutting down plants, but this should not become the excuse for the power generators to take environment and health of the people for granted,” added Nivit Kumar Yadav, programme director, industrial pollution, CSE.

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