In 11 months, Tangedco’s 5 thermal plants consume 31.66 lakh MT excess coal

The five thermal power plants of Tangedco are consuming 14 per cent to 42 per cent more coal for generating per unit of energy, according to Central Electricity Authority (CEA). A conservative estimate shows that Tangedco’s thermal power plant (TPS) consumed 31.66 lakh metric tonnes of coal in excess between April 2021 and February 2022, thereby costing several crores for the public sector company.

In a note to all the generation companies, CEA said that based on the generation and consumption data reported by power utilities for the period April 2021 to February 2022, it is observed that the specific coal consumption (SPCC) is high in some of the plants against the average SPCC of 0.68 in domestic coal-based plants of the country. The coal used to produce one unit of energy is termed specific coal consumption.

North Chennai Thermal Power Station I and II with a combined capacity of 1,830 MW consume 0.946 kg of coal for generating a unit of energy, which is 42 per cent more than the national average of 0.68 SPCC. The 1,050 MW Tuticorin TPS consumed 0.925 kg of coal per unit of energy as against its designed SPCC of 0.71 kg of coal per unit while 1,430 MW Mettur TPS I and II had consumed 0.811 and 0.784 of coal per unit respectively.

Overall, all the five thermal power plants have generated 16,273 million units of power in 2021-22 till February, according to the SRLDC data. As per the designed SPCC of the respective thermal power plants, they should have consumed only 111.97 lakh MT of coal for generating 16,273 million units but it consumed 143.64 lakh MT of coal, which is 31.66 lakh MT in excess.

Comptroller and Auditor General’s Audit Report (Public Sector Undertakings) for the year ended March 31, 2019, which was tabled in June last year, had pointed out the poor operational efficiency of Tangedco’s TPS. “Due to excess consumption of 56.85 lakh MT of coal over the norm, Tangedco incurred extra expenditure to the tune of Rs 2,317.46 crore during 2014-19,” the audit report said.

In its reply to the audit, Tangedco had cited the ageing of power plants, poor quality of coal and non-operation of the plant at full load as a reason for the poor efficiency.

Activist and TNEB retired engineer S Neelakandan Pillai said that Tangedco has floated a tender to procure 4.8 lakh tonnes of coal citing a short supply of coal and summer power demand. “If they could manage the coal consumption of the thermal power plants efficiently, Tangedco would not only avoid coal imports but also cut down on the domestic coal bill as well.

A senior Tangedco official said that flexible operation of the thermal power plants to accommodate the renewable energy generation is leading to increased specific coal consumption. “Tamil Nadu has the highest installed renewable energy capacity comprising of wind and solar. Both the solar and wind generation are infirm in nature with huge intra-day variations in the generation. The thermal power plant generation is being ramped up and down to accommodate renewable power which is leading to a loss in efficiency and increased coal consumption,” the official reasoned.