CHENNAI: Except for two units, no thermal power plants in Tamil Nadu have SO2 (sulfur dioxide) emission control technology. Chennai, Neyveli, Thoothukudi and Mettur are the State's four major coal-burning clusters, and of them, Neyveli and Chennai were among the world's top 50 SO2 hotspots in 2019.
As per the latest information available with TNIE, only two units (1,200 MW) of IL&FS Tamil Nadu Power Company Ltd in Cuddalore, out of 40 operational units (13,160 MW) in the State, have installed Flue Gas Desulfuriser (FGD) as of October 2021. Another eight units (3,950 MW) have awarded bids for FGD installation, essentially leaving 30 units (8,810 MW) out of 40 without any significant progress towards installing FGDs.
While Central sector power plants have moved ahead in at least placing orders for installation of FGDs, the private and State sector power plants haven't yet shown any serious intent to comply with the emission limits.
For instance, power plants in north Chennai run by TANGEDCO are particularly sluggish. Only a feasibility study was conducted, and there has been no progress since.
Sunil Dahiya, one of the authors of a recent report titled 'Emission Watch' published by Poovulagin Nanbargal and the Centre for Research on Energy and Clean Air (CREA), told TNIE: "This is a serious health hazard. Despite multiple timeline extensions and dilutions, the progress on retrofitting polluting power plants is depressingly slow. Power plants in Ennore are deteriorating Chennai's air quality."
Reactive gases, such as SO2 and NOx, react with other gases and materials and turn into secondary particles, forming a major portion of particulate matter (PM2.5), which is a health hazard.
Ashwini Kumar Choubey, Minister of State, Union Environment Ministry, acknowledged during the ongoing Winter Session of Parliament that coal-based thermal power plants are a major source of anthropogenic SO2 emission, which contributes to air pollution. In a written response to a query, he said only 20 units in India have installed FGD systems.
The Union Environment Ministry had first issued a notification in December 2015, stipulating norms for SO2 emissions. The initial deadline was December 2017, but it was later extended on a case-by-case basis from 2018 to 2022. On March 31 this year, the ministry extended the deadline to 2025 - an eight-year delay from the original deadline, and 10 years since the notification was first communicated.
Newly-appointed Tamil Nadu Pollution Control Board (TNPCB) chairman A Udhayan said the State government has taken the issue of air pollution seriously and will look into power plants' compliance.
TANGEDCO officials told TNIE steps are being taken to retrofit FGD systems within the extended deadline. "Consultants have been appointed and detailed project reports are being prepared. Work orders will be issued shortly."
According to the Council on Energy, Environment and Water's (CEEW) revised estimates based on new tenders issued, the cost of FGDs is `40-80 lakh per MW, based on the capacity to be retrofitted.