Environment ministry finalises coal thermal power plant categories: What does it say about emission norms compliance

The Union ministry releases list of coal thermal power plants and their categorisation in line with its April 2021 notification

By Anubha Aggarwal
Published: Wednesday 22 December 2021

Nearly 78 per cent of the coal power capacity in India is not liable to meet emission norms before 2024.

The Union Ministry of Environment, Forest and Climate Change (MoEF&CC) has released the final list of the coal thermal power plants and their categorisation in line with the ministry’s April 2021 notification.

In April 2021, the MoEF&CC in amended the 2015 notification to put coal thermal power plants under three categories, determining the ‘third-time’ revised deadline for meeting emission norms.

After eight months of delay, the task force appointed to categorise the plants has finalised the list.

Coal thermal power plants contribute to over half sulphur dioxide (SO2) concentration, 30 per cent oxides of nitrogen (NOx), 20 per cent particulate matter (PM) in the ambient air.

In 2015, the Union Ministry of Environment, Forest and Climate Change (MoEF&CC) introduced a notification directing coal-based thermal power plants (TPP) to comply with stringent emission norms. The deadline was initially set as 2017. Since then, there has been constant push from the industrial lobby to delay the deadline.

As the 2017 deadline approached, the Union Ministry of Power in consultation with the thermal power plants, submitted another phase-in plan to MoEF&CC and requested for an extension of seven years (till 2024) to meet the norms.

After much deliberation in the Supreme Court, the power plants were granted a five-year extension (till December 2022) to meet the deadlines in a phased manner. The 11 plants in Delhi-NCR were directed to comply with the norms by 2020.

This, however, did not deter the pushback by power plants to meet the emission norms. The norms have already been relaxed for two of the five parameters for which they were revised or formulated since the deadline was extended. 

  • In June 2018, water norms for units installed post-January 2017 were diluted from 2.5 cubic meters per megawatt-hours (m/ MWh) to 3 m3 / MWh
  • In May 2019, NOx norms for units installed between 2004 and 2016 diluted from 300 milligrams per cubic meter (mg / Nm3) to 450 mg / Nm3

The dilution in norms and unwarranted deadline extensions of compliance was dissented and in February 2020, the Central Electricity Authority (CEA) submitted a paper urging flue-gas desulfurisation to be installed only in those plants where SO2 concentration in ambient air was over 40 microgram per normal cubic metre (µg / Nm3).

Parameter SOx (mg / Nm3) NOx (mg / Nm3) PM (mg / Nm3) Water (m3/MWh) Mercury (Hg)
(mg / Nm3)
Units installed before December 31, 2003 600 (<500 MW) 200 (≥ 500 MW) 600 100 3.5 0.03 (≥ 500 MW)
Units installed between 2004 and 2016 600 (< 500 MW) 200 (≥ 500 MW) Initial: 300
Revised: 450
50 3.5 0.03
Units installed from January 1, 2017 100 100 30 Initial: 2.5 Revised: 3 0.03

It criticised the MoEF&CC for framing uniform norms for all TPPs across India and advised different norms be set for different TPPs.

Finally, on April 1, 2021, the MoEF&CC released an amendment, superseding the 2015 Notification on new emission norms. The amendment to the notification served to revise the compliance deadline for the third time now.

It puts coal thermal power plant units into three categories:

Category Criteria Deadline for compliance
A Within 10 km radius of the National Capital Region (NCR) or cities having million-plus population


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


C Remaining  plants


Taskforce work

A task force was constituted by the Central Pollution Control Board (CPCB) April 16, 2021, to disaggregate 596 coal thermal power plant units into three categories: A, B and C.

The country’s 596 coal thermal power plant units have been put under three categories: A, B and C. Source: CEA

Independent power plants: Categorised by CEA in association with the concerned state pollution control boards (SPCB). The boundary details of the critically polluted areas were provided by SPCB.

Captive thermal power plant: Categorisation done by the SPCBs concerned in consultation with the CEA.

The draft list compiled by the task force was initially circulated to the power plants for further comments by September 10, 2021. And now finally, the list has been released by the Central for Pollution Control Board in the public domain and to be shared with the coal thermal power plants.

The categorisation by the task force puts approximately 11 per cent of the capacity in Category A and Category B. Nearly 78 per cent of the coal power capacity is placed under Category C. 

Status of category-wise compliance status

The CEA tracks the status of compliance with the SOx norms in terms of installation of a sulfur removal technology: Flue Gas Desulfurisation (FGD).

The installation status can be traced under four progressive stages: Feasibility study, tender floated, tender awarded and FGD commissioned.

An analysis of the December 2021 compliance status according to the CEA showed that only 10 per cent of the capacity of Category A units has so far complied with the emission norms, another 29 per cent has awarded bid but it is not clear if work has been initiated in these units.

Status of Category A power plants and capacity. Source: CEA

There is no plan / or it is not reported by CEA for 17 per cent. Another 25 per cent is at various stages of the feasibility study and 19 per cent has floated the tender but is yet to award the bid.

It takes two years from award of the bid to commissioning of FGD. Considering this, a minimum of 61 per cent of thermal power plants in Category A will miss the 2022 deadline.

An ownership-wise analysis shows that a majority of the coal thermal power capacity that is likely to meet the norms belongs to the central sector, followed by the private sector.

The plants belonging to the state sector: Some have floated the tender or at various stages of feasibility study or simply have not framed any action plan so far.

None of the Category B plants so far have been complying with the emission norms. At least 30 per cent of the capacity has awarded tender, 35 per cent has floated the tender and 13 per cent are at various stages of feasibility study.

Status of Category B power plants and capacity. Source: CEA

 There is no plan to meet the norms for 22 per cent of the capacity. The deadline for Category B plants is 2023. Down to Earth’s analysis shows that 35 per cent of this capacity will miss the deadline again.

For category C plants, 33 per cent of the capacity has already been awarded tender. This means that this capacity could have easily complied with the emission norms by end of 2022.

However, the deadline for these plants has been postponed to 2024. Tender has been floated for 30 per cent of the capacity and 15 per cent is at the feasibility stage. Status is unknown for another 22 per cent.

Assuming that tender is awarded by next year for the plants where the tender is already floated, it is safe to say that the 32 per cent capacity in Category C will still not comply by 2024.

Status of Category C power plants and capacity. Source: CEA

Push to do away with emission norms

The emission norms introduced in 2015 by MoEF&CC have been made a mockery of. The norms have been diluted, deadlines missed and revised to accommodate coal thermal power plants.

Allocation of a minute 22 per cent in Category A and B and 78 per cent in Category C is in itself a clear indication that both MoEF&CC and CPCB are not serious about the implementation of the new emission norms, said Nivit Kumar Yadav, director, Industrial Pollution Unit, Centre for Science and Environment.

The delay in announcing the categorisation has resulted in stalling progress in the implementation of an action plan for compliance with the emission norms, particularly SOx norms.

Even the plants in Category A with a 2022 deadline have not made any progress since the announcement in April 2021 about the revisions in deadline (as reported by CEA).

It is clear from the categorisation list and compliance status given by CEA for December 2021 that 35 per cent of the total coal power capacity belonging to all three categories is going to miss their respective deadlines. Of this, 19 per cent would be category A; 11 per cent from Category B and 70 per cent from Category C.

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