Photo: Thijs Stoop/Unsplash.
New Delhi: For years, the government of India has avoided imposing strict air pollution standards on thermal power plants. Even as Indian cities climbed to the top positions in the list of most polluted cities, it postponed emission standards and in 2020 actually lowered the limits for emission of nitrogen oxides (NOx), toxic compounds that can cause severe respiratory diseases, by thermal power plants.
Now, an international group of experts promoting clean coal have recommended the government to revisit their recent move to lower the standards. The IEA Clean Coal Centre (IEACCC), in a report entitled ‘A Pathway To Reducing Emissions From Coal Power In India’ released in February 2021, has said that India’s original emission standards can largely be met using relatively inexpensive measures. 1
These findings are in contrast to claims made by the government of India (including the Supreme Court) and the results of tests conducted by government bodies including NTPC Limited 2, India’s largest thermal power producer, to justify relaxing the emissions standards.
IEACCC is a non-profit technology collaboration programme formed under the auspices of (but independent of) the International Energy Agency, an autonomous intergovernmental organisation.
The IEACCC conducts research to promote the use of coal through ‘clean’ i.e. low emissions and high efficiency technologies, and is supported by industrial partners including coal mining firm Anglo American, thermal power equipment supplier Doosan, the government of India-owned Bharat Heavy Electricals, Ltd., as well as seven national governments including those of the US and Japan and the European Commission.
The recommendation comes even as over half the capacity of India’s thermal power plants are expected to miss the 2022 deadline for capping their emissions at the lower standards. India’s power sector is responsible for around one-third of all NOx emissions and second highest after vehicles.
NTPC and the power ministry have not responded to questionnaires sent on March 2, 2021, regarding the findings of the IEACCC report.
Blaming the technology
Under norms introduced in 2015, power plants commissioned between 2003 and 2016 were required to cap their emissions of NOx at 300 milligram per cubic metre (mg/m3). These power plants accounted for 197 gigawatt coal capacity or 65% of India’s total installed capacity.
In October 2020, the government of India diluted the air pollution norms by increasing the emissions cap by 50% to 450 mg/Nm3 3. It also pushed ahead the deadline to meet these norms from 2017 to 2022.
“Reconsider the relaxation of the NOx standard to 450 mg/m3,” read the recommendation in the IEACCC’s report.
Power companies have justified the need to relax the 300 mg/m3 norms based on a comparison between two methods for NOx control.
‘Primary methods’ include combustion modification through installing low-NOx burners and overfire air. The ‘secondary methods’ include selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR).
The companies say that ‘secondary methods’ are expensive and not working for Indian plants and that ‘primary methods’ can’t do enough to meet the 300 mg/Nm3 standard.
But the IEACCC report says otherwise. It says that ‘primary methods’ can cut the pollution to meet the 300 mg/m3 limit and so dilution in standards is not necessary. It also said that primary methods along with optimisation and accurate monitoring of coal combustion in power plants alone can help significantly reduce NOx emissions.
In fact just months before its report, in October 2020 the Indian aluminium maker Hindalco Industries had demonstrated this in its units Mahan, Madhya Pradesh, and Sambalpur, Odisha.
“Power plants think that they have to achieve the standard of 300 mg/Nm3 every second of their operations, but that is not right,” Małgorzata Wiatros-Motyka, an analyst at IEACCC and one of the authors of the report, said in an interview to this author. “There should be some clarification on this by the government, these standards should be met on a rolling average basis.”
In fact, in a study of seven units of four power plants run by the government-run NTPC and Adani Power, India’s largest private sector power producer, five units were found already complying with the 300 mg/Nm3 norms using primary methods alone. These belonged to both companies while the two units that weren’t found complying belonged to Adani Power.
Even before the study, the Central Pollution Control Board (CPCB), India’s chief environmental agency, had found that most of India’s power plants were already meeting the 300 mg/m3 levels and new technologies would better help meet these standards, as Business Standard reported in August 2019.
The IEACCC report suggests that there should be strong incentives for the power plants to meet the emission standards. These could include placing compliant plants higher in the merit order system through which plants sell their electricity, or by imposing stronger penalties on plans that do not comply.
Germany, the EU and the US are already meeting norms far lower than 300 mg/Nm3 limit using a combination of primary and secondary technologies. China, which set the world’s strictest norms of 50 mg/Nm3 for its coal power plants, is also following these.
NTPC had also based its argument for relaxation of standards using results of pilot tests of the SCR and SNCR technologies.
The NTPC presented the results of these pilots to the CPCB at a meeting on November 2, 2019, where they declared that both the technologies “are not suitable for installation” in Indian power plants. Being India’s largest power producer, NTPC’s results are considered as a stamp of approval for the suitability of these technologies for other power plants in India.
Małgorzata said that “these pilots that tested the SCR and SNCR technologies were not full-scale trials. These technologies should be further explored with proper pilots. They can be adapted to the high-ash conditions associated with firing Indian coal.”
Two sources working with the companies that conducted pilots with NTPC said that the companies conducting these pilots testing SCR and SNCR faced a lot of problems with “full control” of the processes. They said that the NTPC did not support them with primary measures required to do the tests and a few necessary steps during the pilot were not followed by the plants.
Meanwhile, power companies led by NTPC are seeking to further dilute the emission norms, this time for plants that were built after 2017 and which are required to meet an emission limit of 100 mg/m3. In the later half of 2020, NTPC also submitted the same results of its pilots to the Supreme Court of India to justify this dilution. No decision has been made yet.
The IEACCC report said that based on appropriate practices, primary measures and secondary measures can satisfy the 100 mg/m3 standards for new plants. “The limit of 100 mg/m3 for plants built after January 2017 should be upheld,” the report said.
Bhasker Tripathi is a Climate Change and Resources Research Fellow with Land Conflict Watch, an independent network of researchers studying land conflicts, climate change and natural resource governance in India. Twitter: @BhaskerTripathi.