The Indian power ministry's proposal to selectively implement emission reduction norms rests on contentious assertions | Photo: Powerline Magazine

How a dubious study is being used to undermine India’s emission norms

The Ministry of Power could be setting a dangerous precedent by putting its weight behind a contentious report in order to water down emission norms for thermal power plants

The seemingly never-ending saga of implementing emission norms for India’s thermal power plants got its latest chapter this fortnight. Barely a day into the new year, a memo issued by the Ministry of Power (MoP) and addressed to the Ministry of Environment, Forest and Climate Change (MOEF&CC) proposed major changes in the plan to implement sulphur-reducing equipment in power plants across the country. Prominently citing financial impacts of installing the equipment, known as flue gas desulphuriser or FGD, the MoP advocated for graded implementation in accordance with ambient air quality levels at the power plant sites.

While the current deadline for implementation is set for 2022, the memo provided no new dates for implementation.

A pursuit of uniformly “good” air quality across the country and economic feasibility are the stated rationale. “The target should be to maintain uniform ambient air quality across the country and not the uniform emission norms for thermal power plants. By implementing uniform emission norms of TPS, may in turn result in different air quality at different locations,” says the memo, undersigned by Nishat Kumar, under-secretary at the MoP. The text, explicitly approved by Minister of State (IC) Power RK Singh, though, falls short of explaining why this is an inherently bad thing.

The memo goes on to propose classification of regions into five categories, according to air quality, to guide prioritised roll out of FGD technology in a phased manner. These recommendations, according to the document, rely completely on a singular report submitted by the Central Electricity Authority (CEA) to the MoP.

Shaky Foundations

A Paper on Plant Location Specific Emission Standards, the basis of the power ministry’s memo to the environment ministry, was conceived in January 2020 in a review meeting on the installation of FGDs chaired by Singh. The objective of the review was to suggest “plant location specific emission standards with suitable basis to be taken up with MOEF&CC.”

Accordingly, CEA’s report seems to invert the scope of emission norms with ambient air quality taking precedence over individual contributions of SO2 by thermal power plants. “Power plants located in an area, where quality of air is very good in terms of SO2, can be exempted from installation of additional equipment to control SO2 emission from stack. A large number of thermal power stations are located in remote locations away from towns with little habitations around. Thermal power plants located in remote locations, ambient air quality (AQI) can be made as the guiding factor for formulating emission control,” reads the report.

Armed with ambient air quality data provided by power plant operators covering 36 GW of power, the CEA classified areas according to SO2 levels and proposed priority installation of FGD equipment in areas averaging higher than 40 μg/m3 of SO2 levels over 24-hour periods. As per the CEA classification and the MoP memo, over 75% of the thermal power plants analysed require “no action” at present. Less than 20% have been highlighted for FGD installation in the first phase.

SO2 Levels in the vicinity of Thermal Power Plants used to classify power plants | Source: CEA

“There are currently many supply chain roadblocks when it comes to FGD technology, for which we have to demand on imports. With this in view, it was decided that so as to soften the financial implications of FGD installation, there should be a prioritised roll out according to the air quality in which the thermal plant is functioning,” says CEA chief engineer BC Mallick, who also worked on the paper. “This way we ensure that the burden of unnecessary urgency is not placed on power plant operators who are already functioning in regions with good air. It also gives us time to study the impact of FGD technology in plants where they have already been installed, and to fine tune these considerations for Indian local conditions,” he adds.

While the power ministry has put its weight behind the review mechanism and the recommendations of the CEA, experts have questioned its validity. “The CEA analysis is fundamentally flawed from the outset. Firstly, CEA has prepared these recommendations based on reporting by power plants covering just 36GW, which is just around a fifth of the total 166 GW of thermal power that needs to be compliant. Conclusions drawn from this small sample are bound to be problematic when applied to the rest of the country,” says Karthik Ganesan, who leads the research on the power sector at the Council on Energy, Environment and Water (CEEW).

One of the big issues in the CEA analysis that air quality researchers have flagged is the usage of ambient air quality data from power plant sites that give a heavily distorted picture of emissions from the power plants. According to Ganesan, this faulty premise smacks of a lack of understanding of atmospheric transport of pollutants. “More importantly, thermal power plants are required to have tall chimneys to aid dispersion of emissions from the power plant and which are then diluted by atmospheric mixing. So, ground level ambient air quality monitoring in the vicinity of power plant sites cannot be used as the basis for determining if the power plant needs to control emissions or not. Using this as the main metric to classify regions shows very poor application of the science of atmospheric transport of pollutants from thermal power plants,” he explains.

As it happens, sulphur-rich emissions also contribute heavily to the formation of sulphates in the atmosphere, which add to particulate pollution. In June last year, researchers from IIT-Kanpur published results of real-time source apportionment analyses of Delhi’s ambient air during the two consecutive winters of 2018 and 2019. Researchers found that sulphur pollution in Delhi to be originating all the way in eastern Uttar Pradesh. Other source apportionment studies, too, have pointed to long-range transport potential of thermal power pollutants and atmospheric conversion of SOx and NOx into particulate matter such as sulphates and nitrates.

Interestingly, while the CEA mentions worrying particulate pollution levels and the rapid depletion of SO2 in the atmosphere in the same breath, it does not in any way probe the connection between particulate matter and SO2 emissions. “There is a deep correlation between SOx emissions from thermal power generation and the particulate matter pollution, which has been completely ignored in the analyses. Several studies have established how SO2 emissions in the atmosphere get converted to particulate sulphates within a timeframe of about four days. High volumes of such PM can be seen over peninsular India. Even as far north as Delhi, 40% of the PM in summer months can be attributed to SO2 emissions. This should be less than 1% in clean air scenarios,” explains Soundaram Ramanathan, a senior researcher studying industrial pollution at the Centre for Science and Environment (CSE) in New Delhi.

Mallick, though, says that examples of such transport are often overblown. “Source apportionment studies have shown how far specific pollutants can travel, but there is still a missing aspect in that these particles have not yet been tied back to thermal power in any meaningful way. We are currently working with research institutes such as IIT-Delhi to develop a better understanding of the specific contributions of thermal power emissions towards particulate pollution and the transport potential of these emissions.”

India’s SO2 headache

Over the past few years, India has earned the distinction of being the largest emitter of SO2 in the world, contributing around a fifth of the total global SO2 emissions in 2019. With practically no natural source in the country, India’s SO2 emissions are estimated to be completely anthropogenic. Studies have indicated that around 50% of this burden comes from thermal power.  

India is now the largest SO2 emitting nation in the world | Source: Greenpeace

Experts pointed out that the SO2 is a criteria pollutant – meaning that it is one of six pollutant categories for which ambient air limits are set and which are known to have adverse impacts on public health. For SO2, norms for which the MoP and CEA have sought to weaken, presence over 20μg/m3 (24-hour mean) or 500μg/m3 (10-minute mean) holds severe health risk potential, particularly to the respiratory system. Background levels of SO2 in the ambient air of healthy environments are typically as low as 2μg/m3.

There is little doubt regarding the need for SO2 emission norms for thermal power plants, considering India’s planned use of coal well into the future. Still, implementing new norms, that were set more than five years ago now, has been an uphill battle.

While the implementation of FGD in thermal power stations around the country has been postponed to 2022 from the original compliance date of 2017, efforts to push this further down the road or to do away with the requirement all together have been evident. Last year, a legal appeal from power producers to delay the deadlines was dismissed by the Supreme Court. About a month later, Federation of Indian Chambers of Commerce & Industry (FICCI) wrote to the PMO requesting intervention in the matter citing escalation of costs and potential for increase in power prices. A comparative analysis by CEEW weighing financial and social costs though shows that these arguments hold little weight. The analysis revealed that the capital cost of FGD installation translates to 30-72 paise/ KWh, depending on the capacity at which the plant is operating, plant load factor and life of the plant. The health and social costs drop from ₹8.58/KWh to 0.73 paise/KWh if the coal plants meet the standards.

While industry has dragged its feet over the installation of FGD, the MoP and CEA seem to have now taken on the mantle of weakening the norms. “On the surface, it seems like a transparent attempt by the power ministry to buy more time for the implementation and delay the process further, just like with the rules regulating fly ash utilisation, which is still far from being fully implemented even after 20 years of being encoded,”says Ramanathan. “With this report, the CEA and MoP have sought to turn the entire logic of pollution control on its head. Instead of looking at individual sources, they have considered ambient quality. Will the next suggestion be to keep adding power plants in areas with good air quality until it hits the limit where action is needed? This just doesn’t make any sense,” she adds.

At the CEA, there is little room for such fears.”The worry of pollution increasing is always there but this report is not for general application to industrial or environmental norms. They are specifically for thermal power plants within the current context and timeline, so I don’t see it as setting a precedent,” says Mallick, seeming somewhat less sure than before, when asked about whether this would set a dangerous precedent that would allow higher industrial effluent emissions in areas with low pollution levels.

The ball is now in the environment ministry’s court. With NOx emission norms already diluted and interventions to control particulate matter mainly lying in the public arena, SO2 emissions represent one of the last pillars of accountability for thermal power generators and their contribution to India’s toxic air. While no immediate response has been forthcoming from the MOEF&CC, folding in the face of dubious research will reveal the hierarchies and priorities that dictate India’s environmental regulation.

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