Executive Summary:
The Ministry of Environment, Forest and Climate Change (MoEFCC) reviewed Sulphur Dioxide (SO2) emission standards for coal/lignite-based Thermal Power Plants (TPPs) initially set in 2015. A notification on 11.07.2025, details revised applicability based on TPP category (A, B, or C) and retirement plans. Compliance timelines vary, and environmental compensation will be levied for non-compliance.
Key Points / Main Content:
Revised SO2 Emission Standards:
* MoEFCC Notification (11.07.2025) outlines revised SO2 emission standards for TPPs, considering factors like technology availability, economic feasibility, COVID-19 impact, and ambient air quality.
TPP Categorization:
* Category A: Within 10 km of NCR or million-plus cities.
* Category B: Within 10 km of Critically Polluted Areas or Non-attainment cities.
* Category C: Other than Category A and B.
Compliance Requirements:
* TPPs retiring before 31.12.2030: Exempt from SO2 standards if they submit an undertaking to CPCB and CEA.
* Category A TPPs: Must comply with SO2 emission standards by 31.12.2027; plants commissioned after this date must comply before operation.
* Category B TPPs: Applicability of SO2 standards to be decided by the Central Government based on Expert Appraisal Committee recommendations.
* Category C TPPs: SO2 emission standards not applicable if stack height criteria (MoEFCC, 30.08.1990) is met by 31.12.2029.
Stack Height Criteria:
* All TPPs, regardless of SO2 standard applicability, must comply with stack height criteria (MoEFCC, 30.08.1990) for pollutant dispersion.
Enforcement:
* Non-compliant TPPs will face environmental compensation.
Technology Selection:
* Utilities decide on FGD technology based on cost-benefit analysis.
Coastal vs. Non-Coastal Plants:
* The policy does not differentiate between coastal and non-coastal plants regarding FGD installation.
Impact Analysis:
Thermal Power Plants (TPPs):
* Impact: TPPs must adhere to revised SO2 emission standards based on their category and retirement plans, potentially requiring FGD installation or upgrades to meet stack height criteria.
* Action Required: Determine their TPP category, assess compliance requirements, implement necessary technology, and adhere to specified timelines or submit undertakings for exemption.
Central Pollution Control Board (CPCB) & Central Electricity Authority (CEA):
* Impact: CPCB and CEA are involved in overseeing compliance and receiving undertakings from TPPs seeking exemption based on retirement plans.
* Action Required: Review and process undertakings submitted by TPPs and monitor compliance with SO2 emission standards and stack height criteria.
Ministry of Environment, Forest and Climate Change (MoEFCC):
* Impact: Responsible for setting and enforcing SO2 emission standards, including the evaluation of Category B plants.
* Action Required: Evaluate Category B TPPs based on Expert Appraisal Committee recommendations.
Expert Appraisal Committee:
* Impact: Responsible for assessing Category B TPPs.
* Action Required: Assess Category B TPPs and provide recommendations to MOEFCC.
Key Entities Referenced
Flue Gas Desulphurisation FGD: Technology used to remove sulfur dioxide from exhaust flue gases in thermal power plants.
Ministry of Environment, Forest and Climate Change MoEFCC: The Indian government ministry responsible for environmental protection and regulation.
Sulphur Dioxide SO: A major air pollutant emitted by coal-fired thermal power plants.
Thermal Power Plants TPPs: Facilities that generate electricity by burning fossil fuels like coal or lignite.
Central Pollution Control Board CPCB: A statutory organisation under the Ministry of Environment, Forest and Climate Change responsible for pollution control.
Central Electricity Authority CEA: A statutory body that advises the government on policy matters and coordinates the development of the power sector.
Principal Scientific Adviser PSA: The chief advisor to the government on scientific matters.
National Capital Region: The metropolitan region which encompasses Delhi and its surrounding areas in the states of Haryana, Uttar Pradesh and Rajasthan.
GOVERNMENT OF INDIA
MINISTRY OF POWER
LOK SABHA
UNSTARRED QUESTION NO.4602
ANSWERED ON 21.08.2025
MITIGATION OF SULPHUR DIOXIDE EMISSIONS
4602. SHRI MADDILA GURUMOORTHY:
Will the Minister of POWER
be pleased to state:
(a) whether the Government has accepted the recent recommendation of the
committee led by the Principal Scientific Adviser to withdraw the mandatory
installation of Flue Gas Desulphurisation (FGD) units in all coal-fired thermal
power plants and if so, the reasons for this rollback despite its risks on health
and environment;
(b) whether any alternative technologies or regulatory frameworks have been
proposed to replace FGD systems in controlling SO₂ emissions from thermal
power plants and if so, the details thereof; and
(c) whether the Government is considering a differential policy for coastal and
non-coastal thermal plants based on their access to cheaper alternatives like
seawater-based FGD treatment and if so, the details thereof?
A N S W E R
THE MINISTER OF STATE IN THE MINISTRY OF POWER
(SHRI SHRIPAD NAIK)
(a) to (c): Ministry of Environment, Forest and Climate Change (MoEF&CC)
notified emission standards [including Sulphur Dioxide (SO )] for coal / lignite
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based Thermal Power Plants (TPPs) vide its Notification dated 07.12.2015.
Further, MoEF&CC vide Notification dated 31.03.2021 prescribed for
categorization of TPPs into the following 03 categories for compliance of emission
standards:
(i) Category-A (Within 10 km radius of National Capital Region or cities having
million plus population);
(ii) Category-B (Within 10 km radius of Critically Polluted Areas or Non-attainment
cities);
…..2.- 2 -
(iii) Category- C (Other than those included in Category A and B).
To meet the SO emission norms, Flue Gas Desulphurization (FGD) system is
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being installed in coal/lignite based TPPs.
The SO emission standards prescribed in MoEF&CC Notification dated
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07.12.2015 have been reviewed by the Central Government taking into
consideration the various representations received regarding exemption or
relaxation in timelines of these standards due to limited availability of technology
providers, its techno-economic feasibility, negative impact of COVID-19 pandemic
on supply chain, price escalation due to high demand and low supplies, low SO
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concentration in ambient air and heavy burden on consumers due to increase in
electricity price etc.
Besides, the scientific studies conducted by independent research
institutions regarding effectiveness & rationale behind these standards and its
role in overall ambient air pollution of the region were also considered to evaluate
the need of universal applicability and enforcement of these standards.
Various Stakeholders’ consultation meetings among MoEF&CC, Ministry of
Power (MoP), Central Pollution Control Board (CPCB), O/o Principal Scientific
Adviser (PSA) to the Government of India, Central Electricity Authority (CEA),
Research Institutions were also held in the matter. The recommendations of the
stakeholders’ consultation meetings, including the meeting chaired by the PSA to
Govt. of India, was also taken into consideration by MoEF&CC.
In view of above, MoEF&CC has issued a Notification on 11.07.2025 regarding
applicability of SO emission standards along with timelines for compliance by
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TPPs and its details are given below:
(i) TPPS declared to retire before 31.12.2030 shall not be required to
meet specified standards for SO emissions in case such plants
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submit an undertaking to Central Pollution Control Board (CPCB) and
Central Electricity Authority (CEA) for exemption on ground of
retirement of such plant;
(ii) the existing and under commissioning Category A TPPs shall comply
with SO emission standards by 31.12.2027. Other Category A plants
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to be commissioned after 31.12.2027 will operate only after ensuring
compliance of these standards;
……3.- 3 -
(iii) for all Category B Plants or Units, whether existing or upcoming, the
applicability of SO emission standards, shall be decided by the
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Central Government based upon recommendations of the Expert
Appraisal Committee in charge of Thermal Power Projects as per the
procedure laid in the Notification dated 11.07.2025;
(iv) the SO emission standards shall not be applicable to all Category-C
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TPPs subject to compliance of stack height criteria notified by
MoEF&CC on 30.08.1990 and timeline for compliance of stack height
criteria is 31.12.2029.
The category wise applicability of SO emission standards in TPPs have
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been decided based on detailed scientific studies and analysis of ambient SO
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concentrations across the country, including areas near TPPs. This approach
applies the precautionary principle for controlling and abating air pollution in
densely populated and other air pollution sensitive areas, while also emphasizing
on resource conservation by avoiding additional consumption of water, auxiliary
power, and limestone, and avoiding the increase in carbon footprint/CO2
emissions resulting from the operation of deployed control measures, as well as
mining and transportation of limestone required for these measures.
In all cases where SO emission standards are not applicable, all such TPPs
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(irrespective of location) shall ensure compliance to stack height criteria notified
by MoEF&CC on 30.08.1990 governing SO emissions from TPPs to aid proper
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dispersion of pollutants and mitigate environmental impacts.
Further, TPPs are required to comply with emission standards within the
prescribed time limits, failing which environmental compensation will be levied
on the non-compliant TPPs.
The selection of technology for FGD installation is decided on the basis of
cost benefit analysis by the utility. The policy regarding FGD installation is
irrespective of coastal and non-coastal thermal plants.
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