Health and environmental benefits of implementing the emission standards for coal-based TPP

images-2By Lauri Myllyvirta, Sunil Dahiya*

Based on calculations done using emission data obtained by Greenpeace India from the Central Pollution Control Board (CPCB) under the Right to Information (RTI), more than 76,000 people died due to non-implementation of emission standard notification within stipulated time frame (before December 7, 2017) till now during last 1 year. In 2012, University of Maryland and University of Texas assessed premature deaths resulting from SO2, NOx and PM emissions from 89 coal-based thermal power plant (TPP) sites across India (Cropper et al 2012).

The mean values of deaths per tonne of emissions of each pollutant can be used as the basis for an indicative estimate of the health benefits of implementing the TPP emission standards – or conversely the health costs of delaying implementation. It is notable that the statistical methodology of Cropper et al results in a lower estimate of total health impacts than the estimate of 80,000-115,000 deaths obtained through more detailed atmospheric modeling carried out by Guttikunda & Jawahar (2014), making the estimates conservative.

Furthermore, the total volume of SO2, NOx and dust emissions reported by the CPCB is more than three times as high as the emissions volume estimated by Guttikunda & Jawahar, a difference that is only very partially explained by different base years: G&J emissions estimates are for 2010-11 while CPCB data is presumably more recent. This implies that the health impacts of coal-based thermal power plants are likely even much more severe than estimated by the authors.

Similarly, the mercury emissions from thermal power plants reported by CPCB are more than four times as high as the emissions estimated by United Nations Environment Programme (UNEP, p 216) for the year 2010. Information obtained through an RTI request from CPCB indicates that the full implementation of the TPP emissions standard would reduce SO2, NOx and PM emissions by 48%, 48% and 40%, respectively.

Combining the data from the CPCB and from Cropper et al, results in an estimate that full implementation of the TPP emission standards would avoid approximately 76,000 premature deaths from air pollution exposure every year (90% confidence interval: 52,000 to 96,000). Of this, 34,000 avoided deaths per year (44%) is due to the reduction in SO2 emissions, 28,000 deaths (36%) due to reduction in NOx emissions and 15,000 deaths (20%) due to reduction in PM emissions.

In other words, a 5-year delay to the implementation of the standards results in an estimated 380,000 avoidable deaths, not taking into account increase in coal-based power generation over that period. A delay of five years in the implementation of the NOx limits alone results in a projected 140,000 avoidable deaths. Additionally, 8.7 gigawatts of coal-based capacity has been commissioned in 2017-18 (“Global Coal Plant Tracker”, July 2018) and at least 701 GW is still under construction (CEA, Sept 2018).

If this capacity is not required to comply with the new TPP emission standards, SO2, NOx and mercury emissions per gigawatt of capacity can be expected to be similar to recently commissioned existing plants – the emissions rates for these plants in the absence of new standards are projected from emissions data obtained through an RTI request for seven NTPC coal-based units commissioned in 2012-2016.

For PM emissions, new plants have already been required to comply with the 30 mg/Nm3 limit of the new standards and hence further reductions are not expected. On this basis, we can project that compliance with the new standards will reduce SO2 and NOx emissions from new plants by approximately 89% and 79%, respectively.

A 60% reduction in mercury emissions is assumed from the installation of Flue Gas Desulfurization and Selective Catalytic Reduction devices, in line with CPCB projection for existing plants. Similarly to the calculation for existing capacity, these emission reductions will result in a projected 27,000 avoided deaths from air pollution exposure every year, compared with a situation in which all the plants come online and new emission standards are not enforced (90% CI: 18,000 to 34,000).

Out of this total, 15,000 avoided deaths per year are due to reduction in SO2 emissions, 12,000 due to reduction in NOx emissions, and 1,000 due to reduction in PM emissions. The projected reduction in mercury emissions from the power sector is enormous, approximately 180 tonnes per year. Given that India’s mercury emissions from all other sources except coal combustion in thermal power plants were estimated at 95 tonnes per year in 2010 (UNEP 2013, p.216), the implementation of the TPP emission standards could reduce total national emissions by approximately 40%, even allowing for growth in emissions from other sectors.

In absolute terms, the reduction is equal to three times the total mercury emissions of the United States2 . Implementing the TPP emission standards would highly likely be the largest contribution to reducing mercury emissions to air anywhere in the world since China started implementing similar standards around 2005.

*Greenpeace India


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