Power problem

With Tamil Nadu reeling under severe drought due to which most water reservoirs are practically empty, the condition of the state’s hydro power projects which have to ensure current supply in the upcoming summer, projected to be stiflingly hot, present a dismal situation. 

The state’s hydel power stations are located in the Kundah, Kadamparai, Erode and Tirunelveli TANGEDCO (Tamil Nadu Generation and Distribution Corporation) circles. Each project has many units located high above the sea level that collect and store water flowing down through them from which power is then generated. 

TANGEDCO’s installed capacity is 13, 231.44 MW from hydro, thermal and gas power stations with another 8,470 MW being drawn from non- conventional energy sources including wind, bio mass, cogeneration and solar power units. But TANGEDCO’s main reliance is on hydro (2,307.9 MW), thermal (4,660 MW) and gas (516.8 MW) as non-conventional power is not available throughout the year. Non-conventional power sources include cogeneration (659.4 MW), biomass (230 MW), wind energy (7,685.6MW) and solar power (1,506 MW).

Highly placed sources in the electricity board said that storage as on date was only 25 per cent of the FRL (Full Reservoir Level), which has left officials worrying over how they will get through the summer. Unless there are one or two sharp or heavy early summer showers, the situation would remain grim.

“Hydro power projects are usually small compared to thermal power units, whose output in megawatts is very high, with directly proportional higher cost,” said a TANGEDCO official. “The state’s hydro power units include the ageing Kundah and Pykara projects, Periyar-Vaigai SHEP (Small Hydro Electric Project) 3 and 4 whose power output is 2 X 2 MW and 2 X 1.25 MW. They became operational in 2013 and 2014 respectively, at an estimated cost of Rs 75 core and Rs 87.07 crore, financed by the central government’s Power Finance Corporation.” 

Two other hydro units are the Bhavani Barrage 1 and 2 which are HEPs (Hydro Electric Projects) of 2 X 5 MW each, which became operational at an estimated Rs.185.8 and Rs.183.61 crore in 2014 and 2013 respectively.

TANGEDCO sources revealed that hydro power “Is not resorted to routinely, but kept for summer when the power demand in the state shoots up. Thus, water storage in Bhavani, Vaigai, and Mullaperiyar reservoirs are maintained for such use.” 

It may be recalled that April 29, 2016 saw the state using 15,343 MW the highest peak demand till date. Peak demand is based on morning peak and lighting peak, durations being between 6 am and 10 am in the morning and between 6.30 and 10 pm in the evening when power demand surges due to lights being switched on. Hydro power is used to supplement supply from other sources. 

Till date, hydro power used has been marginal. Of the installed capacity of 2,307.9 MW, hydro supply was 617 MW (January 23), 152 MW (January 24), 540 MW (January 25), 642 MW (January 26), 538 MW (January 27), 712 MW (January 28), 632 MW (January 29) and 370 MW on January 30.

“Hydro power generation in Tamil Nadu is a problem as the state has no perennial rivers. Hydro power will be promising only if such projects are located on perennial rivers” officials said. That is why the state relies more on thermal power, they added. 

The ministry of new and renewable energy database cites the existence of an estimated 20,000 MW of SHP (Small Hydro Power) projects for an 6,474 projects of 25 MW each, “Mostly in the Himalayan States as river-based projects and on irrigation canals in other States” officials added. 

Though the SHP programme was essentially private investment driven, it was later contained without much publicity as such projects have to be started in forest areas and getting permission from the central government’s forest wing was a herculean task. Now states are allowed to start such projects, but with no perennial river in Tamil Nadu, the state has either to get heavy rains or opt for huge thermal power stations.