Categorization of Coal-based Power plants- India

June 30, 2022
Categorization of Coal-based Power plants

By Rupin Chopra and Apalka Bareja

Categorization of Power Plants as per the Notification dated 31.03.2021 of Government of India issued to amend the earlier Notification dated 07.12.2015 regarding emission standards for coal-based power plants

The notification issued by the Ministry of Environment, Forest and Climate Change on March 31, 2021 to amend the Environment Protection Rules and put coal based thermal power plants into three categories – namely Category A, B and C. The notification also stated that a task force will also be constituted by the Central Pollution Control Board to categorise these power plants into these three categories.

Recently the ministry has uploaded the final categorization on the website of the Central Pollution Control Board. Earlier according to the notification issued by the Ministry in 2015 the deadline for the compliance with these regulations was 2017 but the deadline was extended by a period of five years till December 2022. But still the compliances were not met and there was constant pressure to push the deadline and dilute the norms in one way or another.

The norms to be complied with

The parameters or regulations that these coal-based power plants must comply with are mentioned in the table below.

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


Categorization of Thermal Power Plants

The amendment revised the compliance deadlines and different deadlines were set up depending upon the categorization of the power plants. The categorization of the power plants was done based on their location and the task force categorised 596 power plants in the following categories.


S. No. Category Location/Area Timeline for Compliance
Non-retiring Units Retiring Units
(1) (2) (3) (4) (5)
1 Category A Within 10 km radius of National

Capital Region or cities having

million plus population

Up to 31 December


Up to 31

December 2022

2 Category B Within 10 km radius of

Critically Polluted Areas or

Non-attainment cities

Up to 31 December 2023 Up to 31 December 2025
3 Category C Other than those included in category A and B Up to 31 December 2024 Up to 31 December 2025

*Population as per 2011 Census of India and definition of non-attainment cities as defined by CPCB


78% of the power plants fall under Category C and for them the compliances must be met by December 2024. Approximately 11% fall under Category A and approximately around 11% in Category B making up the remaining 22%[2].

Retiring power plants will have to submit an undertaking with the CPCB and CEA for exemption and so that they can comply with the deadline as mentioned in Column (5) of the table above[3].

Penalty in case of non-compliance

The non-retiring power plants must comply with the norms according to the deadlines mentioned in the notification otherwise environment compensation will be levied as a form of punishment as a result of non-compliance.

Non-compliant operation beyond the timeline Environmental Compensation (Rs. Per unit electricity generated)
Category A Category B Category C
0-180 days 0.10 0.07 0.05
181-365 days 0.15 0.10 0.075
366 days and beyond 0.20 0.15 0.10


These are the categories that the coal-based thermal power plants across the nation have been divided into by the task force. The deadline has been time and again delayed ultimately resulting in the stalling of the implementation of an action plan to deal with the emissions norms. Emission from Coal thermal power plants contributes substantially to the degradation in the quality of air due to the presence of harmful pollutants (over half sulphur dioxide (SO2) concentration, 30 per cent oxides of nitrogen (NOx), 20 per cent particulate matter (PM) in the ambient air come from these power plants)[5]. Therefore, it is important for the timely implementation of the norms that have been devised by the Ministry in accordance with CPCB without any unnecessary delay and influence from the power plants to further push the deadline.

[1] Environment (Protection) Amendment Rules, 2021

[2] Minutes of 4th meeting of the Task Force held on 06/12/2021 circulated by the Ministry via order dated 13/12/2021.

[3] Supra note 1

[4] Supra note 1


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