Relaxed sulphur emissions for thermal plants troubling

 It is beyond doubt that coal-fired power is harmful to health and the environment
| Photo Credit:
NAGARA GOPAL

In a gazette notification issued out of the blue last month, the Ministry of Environment and Forests has nearly done away with the requirement of treating sulphur dioxide emissions in thermal power plants (TPPs). Emission reduction criteria will strictly apply only to TPPs in the vicinity of the National Capital Region or other cities with a population of a million of more, called Category A plants. While the Centre, citing certain studies, has given its reasons for doing an about-turn on a stringent policy on sulphur dioxide emissions framed in 2015, these are not wholly convincing.

For plants that are within 10 km of critically polluted areas or ‘non-attainment cities’ (Category B), sulphur emissions will be considered on a ‘case-by-case basis’. This does not seem transparent at all. The remaining TPPs, called Category C, which account for over 75 per cent of coal-fired power capacity of about 220 GW are exempt from treating such emissions. Categories A and B roughly have an equal share in the remaining 25 per cent. The Centre has broadly reasoned, on the basis of studies by IIT Delhi and the National Environmental Engineering Research Institute, Nagpur, that ambient SO2 concentration in 10 cities were well below hazardous levels. It has also noted that the flue gas desulphurisation (FGD) equipment to reduce sulphur emissions is not a viable option; it consumes extra coal, and the ensuing carbon emissions are expected to negate benefits arising from lower sulphur emissions. Besides, it is now argued, Indian coal is low on sulphur anyway, so FGD is a big one-time cost.

The latest flip-flop raises questions about power pricing for TPPs which have already installed FGDs. However, the 2015 policy, based on an IIT Kanpur study, was based on the assumption that SO2 emissions are linked to hazardous PM 2.5 emissions. Now, category A plants alone need to meet certain sulphur emissions criteria — and by the end of 2027, despite the fact that these norms have been in existence for a decade with deadlines being shifted time and again. It is beyond doubt that coal-fired power is harmful to health and the environment. If India is serious about creating more TPP capacity alongside renewables, it must pursue this option with a sense of responsibility.

There are a few oddities to this decade-long history of TPP emissions regulation. The 2015 regulation did not recommend FGD as a technology, but yet it came to be regarded as the only option to the virtual exclusion of other technologies, such as dry sorbent injection. In fact, regulations on using coal with no more than 34 per cent ash content were relaxed in 2020, possibly on the presumption that FGD would take care of this aspect as well. Now, it would seem that there is neither a regulation to curb ash content nor sulphur emissions. If the idea is to only curb carbon emissions from burning coal and hopefully trade it against offsets, it amounts to a limiting, if not cynical, view on cleaning up our atmosphere.

Published on August 4, 2025

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