Even as Prime Minister Narendra Modi on Saturday ‘dedicated to the nation’ the Raichur–Solapur 765kV second circuit line, the key grid link between the southern region and the rest of the country is nowhere close to alleviating the woes of the power-starved south.
Despite a rated capacity for wheeling 2,100 MW of power flows, transmission constraints would continue to bottle up power flows to the southern region from the rest of the country as a dozen associated transmission lines on either sides of Raichur and Solapur are badly delayed.
After factoring in for contingencies, the net benefit in terms of incremental flows to the south on account of the new line is just around 350 MW, as per the website of the national grid manager POSOCO.
In effect, the relief to the south in terms of simultaneous import capacity (or power flows at the same time) is likely to be restricted to 350 MW, enabling the import capability of the southern region to go up to about 4,000 MW from the estimate of 3,650 MW prior to the commissioning of this new line, government officials involved in the exercise said.
The new line that was commissioned on June 21 this year will wheel power to the southern region alongside a parallel line with a similar capacity that was commissioned earlier on December 31, 2013. Despite the two Raichur-Solapur lines going on stream, one link would have to be kept as a buffer under the single contingency (N-1) rule, which covers the possibility of the loss of any single transmission line at any time. An official involved in the exercise said that apart from the fact that the capacity of 2,100 MW of the single line, on paper, is rendered redundant on account of the associated lines not coming though, there is the additional problem of setting aside the reliability margin for an event such as the tripping of the 2,000 MWe (mega watt electrical) Kudankulam atomic station. A margin of at least 750 MW is to be set aside for this, leaving only a free transfer capacity of about 350 MW and giving the southern region an effective relief of just that much. A Power Grid Corporation (PGCIL) official stated for the record that work on the other lines is “being expedited”.
Among the lines that should have come up simultaneously, but are hanging fire include a crucial 6,000MW HVDC line from