The retirement of these four units, each with capacity of 62.5 Mw, would mean a loss of 250 Mw to Odisha since the entire power generated by NTPC's TTPS is supplied to state owned bulk power purchaser Gridco as per a power purchase agreement (PPA). The four units were identified to be phased out since they are old units commissioned during 1967-69.

“Over the years, NTPC has undertaken massive renovation and modernisation works of TTPS under various phases with a capital expenditure to the tune of Rs 750 crore which has already been approved and capitalised by Central Electricity Regulatory Commission (CERC) up to 2014 and the said amount is in the process of realisation by NTPC from Gridco through tariff. The CERC by its order dated June 19, 2002 has extended the useful life of TTPS for 20 years (up to March 31, 2021)”, Sangramjit Nayak, additional secretary (energy), Odisha, said in a letter to chief engineer (data management & load forecasting division), Central Electricity Authority (CEA).

The state government argued that post renovation and modernisation works of TTPS, the station has been consistently running at a PLF (plant load factor) of 90 per cent and above. Also, the operating parameters have noticeably improved over time.

Owing to its geographical location in the vicinity of coal mines, TTPS is considered as a reliable source of dedicated power.

“In view of the above facts, it will not be prudent to concede the retirement of Stage-I units of TTPC during the 12th Plan as proposed by CEA as huge fund has been invested in the renovation & modernisation (R&M) of the units. Therefore, CEA and Union ministry of power are requested to see that the capital expenditure made so far in R&M are fully utilised and the benefit of the same is being passed on to the consumers of Odisha upto 2021 as approved by CERC”, the letter added.

The retirement of old thermal units is as per the National Electricity Plan (2012-17) wherein 4,000 Mw capacity has been identified to be retired, mainly non-reheat type coal-based units, lignite and gas-based units. These units are to be retired in a phased manner during the 12th Plan period (2012-17). Presently, the NTPC’s TTPS plant, dedicated entirely to Odisha, has a capacity of 460 Mw. The utility major has plans to add two 660 Mw super critical units to this power station which it had acquired from the erstwhile Orissa State Electricity Board (OSEB).

The retirement of old thermal units by the central power ministry and their subsequent replacement with new and more efficient units are aimed at improving the efficiency of the coal-based generating stations. This has been identified as an effective way to use the fuel and minimize the greenhouse gas emissions.

The goal of achieving the increased efficiency of coal-based thermal power stations is being taken up by increasing the units size, using clean coal technology, renovation and modernisation of old units, energy efficiency improvement, coal quality improvement and retirement of old and inefficient units.