TANGEDCO's carbon di-oxide emission increased by 33 per cent in the last five years

CHENNAI: Despite increased renewable energy usage in the state, fossil fuel-derived energy sources constituted 71 per cent of TANGEDCO's overall energy supply with the absolute Carbon di-oxide (CO2) emission rising to 757 million tonnes in 2021-22, recording an increase of 33 per cent in the last five year.

TANGEDCO's emissions from coal and lignite show an increasing trend and have exceeded pre-COVID-19 levels, according to a study on TANGEDCO's Carbon emissions from 2017 to 2022 by Auroville Consulting.

The state's power demand increased from 75,218 million units in 2017-18 to 1,00,559 MU in 2021-22. The power demand witnessed an increase of 25,341 MU from 2017 to 2022, with renewables accounting for 27 per cent of this increased demand. However, overall fossil fuel-based energy constituted 76 per cent of the total energy in 2017-18, experiencing a slight decrease to 73 per cent in 2021-22.

"TANGEDCO's absolute CO2 emissions rose from 570 million tonnes of CO2 in the fiscal year 2017-2018 to 757 million tonnes of CO2 in 2021-22, indicating a 33 per cent increase in the emissions. Lignite-based power, known for its higher emission intensity compared to coal, experienced a significant surge, its total CO2 emission more than doubled between 2017-18 and 2021-22. In 2021-22, it constituted 17.68 per cent of TANGEDCO's total CO2 emission.

Despite this substantial increase in lignite usage, coal-fired power generation remains the primary contributor to TANGEDCO's overall CO2 emissions, while emissions from gas power plants remain marginal, " it said.

The weighted average emission factor for TANGEDCO's power experienced a slight decrease from 2017-18 to 2021-22, shifting from 0.76 tCO2/MWh (tonne CO2 per megawatt hour) to 0.75 tCO2/MWh. "This indicates a 0.77 per cent reduction in emission intensity. However, when compared to the weighted average emission factor of India (CEA 2022) at 0.72 tCO2/ MWh in the fiscal year 2021-22, TANGEDCO's emission factor remains higher. Lignite, with an emission factor of 1.27 tCO2/MWh, stands out as the most emission-intensive energy-sourcing option for TANGEDCO, " the study report said.

While the union government has targeted to achieve net-zero emissions by 2070, the Tamil Nadu government has set an ambitious goal of achieving the target by 2040.

The report recommended that the energy department mandate TANGEDCO to disclose its CO2 emissions and sought emission reduction targets for the utility.

The consultant also sought phasing out of the most polluting power plants like 3100 MW of the state's coal power plants which are aged 20 years or more.