Delhiites may hope to see less power cuts this winter. The reason: the electricity transmission utilities have started work on a new technology that makes power lines immune to tripping from fog — an annual threat to uninterrupted supply in winter.
Delhi Transco, along with Power Grid Corporation Limited (PGCL), have begun installing polymer insulators in 400 kV (high voltage) lines so that fog, mist or any other kind of moisture heavy in the air in winter does not cause the lines to trip.
As of now, these transmission lines carry insulators made of porcelain that do not protect the transmission from fog-related tripping.
Delhi Transco and PGCL will replace 500 such porcelain insulators with polymer ones by December 15 — before Delhi's dreaded season of heavy fog sets in.
"We needed this technology shift because Delhi's winter is notorious for fog and the resultant tripping of power supply every year," said Rajendra Kumar, Delhi power secretary. "We have identified the lines near water bodies as the priority, because areas near water bodies tend to get foggier."
In all, Delhi will have to replace around 8,000 such insulators over one year, the process for which will start now. The total network of these lines in Delhi is about 125 km. The cost of the total project is Rs 12 crore.
Every year, fog trips power transmission lines in North India as dust particles present in the moisture causes short-circuit.
Last year in March, large parts of Haryana, Uttar Pradesh and Delhi suffered long outages when several 400-kV transmission lines tripped due to heavy fog. Power lines of Northern Railway too snapped, disrupting railway services.
Utilities like Delhi Transco and PGCL wash the lines prior to winter so that the number of trippings can be minimised.
"To speed up the process of procuring the insulators, we asked PGCL, which was purchasing a lot for itself, to buy for us as well," said a senior Delhi Transco official. "The time saved has helped because we can claim to have a zero-outage winter this year."
Apart from replacing installing polymer insulators in the 400 kV lines, Delhi Transco is also washing the less powerful 220 kV lines with distilled water.
Last year, PGCL had started washing its lines with hosepipes mounted on helicopters.