New plans to curb thermal plant pollution

In a suo motu statement in the State assembly in the recently concluded session, Chief Minister Edappadi K Palaniswami announced that new equipment would be installed at a cost of Rs 3,000 crore at the five existing thermal power stations in the State to reduce the emissions to the levels prescribed by the new environmental norms.

A senior Tangedco official said that the consultant would submit a report recommending methodology on going about installing the equipment to reduce various emissions - sulphur dioxide (SO2), oxides of nitrogen (NOx) and particulate matter (PM) in the flue gas.

“After getting the report of the consultant, we will call for the tenders to install flue gas desulphurisation (FGD), which is a set of technologies used to remove sulphur dioxide (SO2) from exhaust flue gases from fossil-fuel power plants, and retrofitting electrostatic precipitators would help reduce the emission of particulate matters. All the existing thermal power plants will comply with the new environment norms by 2022,” the official told DT Next.

The consultant was appointed in line with the Ministry of Environment, Forests and Climate Change’s December 2015 notification brought out new norms for coal-based power stations to cut down emissions of particulate matter (PM10), sulphur dioxide and oxides of nitrogen to improve the air quality around power plants.

The new air pollution norms for the existing thermal stations stipulate controlling SO2, NOx and PM in the flue gas by December 2017 by retrofitting the existing thermal stations. However, the power generation companies, including Tangedco,missed the deadline and sought five years extension citing financial constraints and a long period of shutdown required to undertake the retrofitting work.

Electricity Minister P Thangamani, while addressing at the Power Minister’s Conference at Gurgaon in March this year, stated that Tuticorin Thermal Power Station (TTPS) and Mettur Thermal Power Station I (MTPS I) comply with the norms for both SOx and NOx according to the readings taken by Tangedco and Tamil Nadu Pollution Control Board (TNPCB). “Further, Mettur Thermal Power Station II also complies with the revised norms for all the three parameters, SOx, NOx and PM,” he said.

“While the revised environmental norms are already met with the existing system itself, it has been proposed to install pollution controlling equipment at Tangedco’s thermal power stations to reduce SOx emission as per the request of the Central Electricity Authority. Also, in order to consistently keep SPM values within prescribed limits at 210MW units of TTPS, MTPS I and NCTPS I, it is proposed to retrofit/modify the ESP in all units to bring down the SPM value to within the future norms,” he told the conference.

Thangamani said that the estimated cost for complying with the environmental norms for all the thermal power stations and ongoing projects is estimated to be Rs9,000 crores for the installation of the FGD and Selective Catalytic Reduction (SCR), which removes harmful nitrogen oxide emissions.

A senior Tangedco official said that considering the quantum of work involved, huge capital outlay and large unit outages for carrying out the works, the utility has requested the Union Power Minister to recommend to MoEF&CC for extension of time for at least another five years to complete the works in a phased manner. “The discoms, including Tangedco,are paying Clean Energy Cess of Rs 400 per tonne for coal. The amount could be utilised for funding for compliance to environmental norms,”the official said.

Environmental activist NityanandJayaraman said that the installation of equipment to control emissions in coal-fired power plants would have a positive impact provided there was no increase in the pollution load in that area or air shed in the form of new polluting industries.

Citing pollution control measures undertaken in New Delhi, he said that in 2001, all the public transport vehicles like buses and auto rickshaws were converted into CNG to control emissions. “Immediately there was a good reduction in pollution levels. At the same time, thousands of new private vehicles started hitting the road. Within six years, all the gains started reversing. Now New Delhi is the most polluted city,” he noted.

Jayaraman said that after controlling emissions from the thermal power plants, the Tangedco should not go on constructing new plants at the vicinity of the existing power plants. “Gains made out of controlling emissions from 3300 MW capacity coal-fired thermal plant at Ennore would get offset by construction 2400 MW capacity new coal-fired power stations. The air quality will not improve if you keep increasing the number of polluting industries in the particular air shed,” he warned.