THOOTHUKUDI: Even as the coal shortage has struck the electricity generation in the State, the Thoothukudi Thermal Power Station (TTPS) authorities have worked out a sustainable plan to ensure power supply during the peak hours (from 4 pm to 10 pm) so as to conserve coal consumption. The power demand for the daytime is met by renewable energy like solar and windmills, said a top official.
The TTPS has five units with a total production capacity of 1050 Mega Watt (MW). Each unit generates 210 MW. Sources said that each unit requires 3,500 to 4,000 tonnes of coal per day ie., at least 20,000 tonnes of coal per day is required to run 1050 MW capacity. The TTPS, which usually receives two vessels of coal ferrying 50,000 tonnes each in a week is now receiving only one vessel for 10 days due to a shortage of coal, added sources.
According to the sustainable plan, the TANGEDCO hand trips four out of five units of TTPS ( unit 2,3,4 and 5) during the daytime and all the units of the plant are operated during the peak hours from 4 pm to 10 pm. Unit 1 is operated non-stop.
As per the instructions from the Tamil Nadu Load Dispatch Centre (TN LDC), a senior official from TTPS, told TNIE that the four units are hand tripped in tandem after 12 am every day as power demand subsides in the late hours, and they are lighted up again after 2 pm. By doing so, two-thirds of the coal consumption is reduced, he added.
The solar power generation units start supplying power from 8 am, which meets the demand for the day time. "The state generates an average of 3,000 MW of electricity from the renewable sectors of solar and windmills which shoulders TANGEDCO in the day hours", the official said.
When asked if such repeated practice of hand tripping and lighting up would weaken the age-old units, the official explained that the maintenance cost is comparatively lower than the power purchase price. Also, the sustainable operations of the coal-fired thermal power generation units is a temporary measure, he added.
Another senior official from the engineering section, wishing anonymity, told TNIE that this is strategically a wiser plan to tide over the prevailing coal crisis. The sustainable plan has been devised to consume coal for peak hour demands and to largely rely on renewable energy which is abundant during summer for the daytime. The purchase price of electricity costs `12 per unit during the evening peak hour, while the cost of production per unit is `6, he said and added that "by implementing the sustainable plan, we save `6 per unit and also the coal consumption".
However, a leader of the labour union told TNIE that repeated lighting up doubles the consumption of 'heavy oil' from 15 kilolitre to 30 kilolitre per day for an unit. This sustainable plan is to weaken the decades-old TTPS to be shut permanently as TANGEDCO had neither initiated installation of Flue-gas desulfurization (FGD) technologies to reduce pollution nor retirement plan, he criticised.
Another official said that the coal crisis is a national issue and there is a need for a sustainable plan to meet the demands with the available coal quantum. The coal supply to the thermal power plants in Tamil Nadu and other states has been slowed down in the recent months resulting in power outage.
When asked about the enforcement of a sustainable plan for TTPS while there are no such strategies for the thermal power plants in other parts of the state, the official said that the frequency has been reduced to TTPS as vessels need to move around Sri Lanka to reach Thoothukudi. Whereas, the coal supply frequency is adequate to Chennai port since it is closer to the Paradip port from where coal is ferried, he added.
The units 1, 2, 3, 4, and 5 of the TTPS were started in 1979, 1980, 1982, 1991 and 1992 respectively.