Indian utilities must stop stalling – emission standards are achievable

Bigstock, ©Abir Roy Barman
A September 2022 article from the Centre for Science and the Environment (CSE) in India reports that less than 7% of the Indian coal utility fleet is in compliance with emission standards for particulate matter (PM), sulphur dioxide (SO2) and nitrogen oxides (NOx).

These standards were originally set in 2015 with a deadline for compliance of 2017. In early September the deadline for coal-fired power plants to fit SO2 emissions control equipment, was extended for the third time, by another two years. First the deadline was amended by region, ending in 2022, then last year it was extended again to 2025. Officials now say power plants will be forced to retire if they do not comply with the SO2 emissions standard by the end of 2027.

This stalling in the adoption of emission limits is resulting in a worrying delay in the implementation of control measures. For example, the graph below shows the growth in coal capacity in India over the last two decades. Despite the introduction of SO2 emission limits in 2015, the growth in flue gas desulphurisation (FGD) installation (shown in grey and blue) remains low. DeNOx systems appear to be operational on 25% of the Indian coal fleet, at most.

More coal-fired units will fit SO2 and NOx control technologies as the deadline for compliance becomes imminent, or into force.  The Indian government continues to allow delays in the implementation of the emission limits based mainly on industry stakeholder arguments, many of which do not stand up to technical scrutiny. Coal industry sources claim that Indian coals differ from those used elsewhere (as they are higher in ash, have lower volatility and can be lower in sulphur) and suggest that, because of this, emission control technologies which succeed elsewhere in the world will not work as well in India. This is largely not the case. Whilst Indian coals will sometimes prove more challenging than other coals, studies have shown that modifications to the plant and the control technologies can ensure that the reduction efficiencies for PM, SO2 and NOx achieved elsewhere can be achieved in India too. A previous report by the ICSC (Adams and others, 2020) presented evidence showing that it is possible for many Indian plants to comply with the new emission limits.

An imminent new report from the ICSC, produced with funding from the US Department of State, reiterates this, providing even more technical detail on the effectiveness of emission control technologies on Indian coals. The one pollutant which may remain challenging is mercury. Co-benefit mercury reductions of up to 50% may be achievable in many Indian plants which install PM, SO2 and NOx controls. However, original analyses by the ICSC suggest that mercury control below the current standard in India (30 µg/m3, which is an order of magnitude more lenient than emission limits in the EU and the USA), may be challenging due to the tendency for mercury to remain in its elemental form in Indian combustion conditions. Maximising mercury reduction through co-benefit routes should be built into all emission control tenders for any pollutant – PM, SO2 and NOx – within India going forward. This would reduce the need for, and cost of, mercury-specific reduction strategies in the future.

All Indian emission limits should be accepted and implemented in India so that the sector can move forward on a solid basis. Any continuing fluidity of policy could contribute to wasted time and money as well as loss of life.

The financial analyses are clear – in terms of lives saved, improvement to the public and health services and increase in GDP, “expensive” emission control systems pay for themselves.

Strategies for effective pollution control in India include:

  • Legal enforcement of the emission limits as soon as possible, with real consequences for non-compliance.
  • Use of the emerging continuous emissions monitoring network in India to enforce compliance and identify sources of concern.
  • Rapid completion of current and impending retrofits and tenders for the installation of control technologies and widespread sharing of experience to promote further uptake and avoid common complications.
  • Tightening of maintenance protocols to ensure that existing and new pollution control systems are operated correctly and kept at, or as near as possible to, design performance throughout their operation.
  • Development of in-country skills and the establishment of a highly qualified Indian pollution control sector in alignment with the national “self-reliant India” goals.
  • The requirement for all tenders for any plant upgrade or retrofit, be it for efficiency or emission reduction, to include maximisation of mercury co-benefit effects as standard going forward.

This article is based on a significant project of work undertaken by the ICSC on behalf of the US Department of State in India. More details can be found at: