Electrifying question: Should overhead lines go underground?

Electrifying question: Should overhead lines go underground?
New Indian Express

BANGALORE: The huge damage to the city power network by the recent rains has set off a debate whether the overhead lines (OH) should be placed underground to make distribution safe and reliable.

A retired KEB chief engineer has argued in favour of such a change. He has categorically stated that cost is not the issue.

Rubbishing the myth that Bescom cannot afford UG (that is six times costlier than OH), P.S. Jagannath Gupta, retired KEB chief engineer and former technical advisor to the KPTCL CMD, has proposed a three-pronged strategy to make the city power distribution safe forever.

The cost is completely recoverable in the short term, he added. Gupta has power distribution experience spanning three decades.

N.S Kumaraswamy, Chief Engineer, Bangalore Metropolitan Area Zone, Bescom, recently told this paper that UG was not economically viable.

‘‘The UG cost will ultimately be passed on to the consumer. Are you willing to pay Rs. eight per unit instead of the current Rs. 1.85 per unit?’’ was his query.

Here’s Gupta’s reasoning: ‘‘Ensuring safe and reliable supply in Bangalore is practical as over 80 percent of Bescom’s 22 lakh paying customers contributing to its Rs. 350 crore per month turnover are here."

"If the utility provides reliable supply, consumption will rise and revenues will greatly increase. All capital expenditure financed through external borrowing can be paid off in four years, as Bescom will have earned enough. What remains is only the interest burden, a part of revenue expenditure.’’

Gupta’s remedy is direct and pragmatic. He has suggested that all 11 kV lines should be converted to Ring Main Unit UG; all 400 V lines to Aerial Bunched Conductors (ABC) and all 14,000 transformers in the city to Unitised Sub-stations.

UG eliminates the problem of conductors snapping during thundershowers. It ensures security as Ring Main Unit UG has an alternative source of supply unlike radial OH which has a single source.

Though locating a fault and fixing it takes longer, UG which has a 40 percent buffer can immediately switch to the second source while the fault is being fixed.

‘‘But cable damage through digging by BSNL, BWSSB and private cellular service providers has to be guarded against,’’ Gupta pointed out adding that this was a bureaucratic issue and not technical.

ABC are insulated OH lines. By installing them, Bescom need not worry about safety, power theft or tree pruning before monsoon. ABC costs three times more than radial OH, but is worth it in the long term.

Bescom has installed 2 km stretches of ABC on a experimental basis in Rajajinagar and Indiranagar and the performance has been good.

Unitised Sub-stations (like the one opposite Safina Plaza) are compact, enclosed and aesthetic. They do not encroach on footpaths or endanger pedestrians.