Cleaning at a sky-high cost

A new technique of washing power transmission towers with water sprayed from helicopters may shoot up the cost of electricity ‘wheeling’ (transmission) in the winters, reports HT Correspondent.

A new technique of washing power transmission towers with water sprayed from helicopters may shoot up the cost of electricity ‘wheeling’ (transmission) in the winters.

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Powergrid Corporation, the national electricity transmission utility, is toying with this costly idea imported from New Zealand, whose experts have charged Rs 8.2 crore to wash the 16 most pollution-affected transmission lines around Delhi.

This, when Powergrid is also trying out a much cheaper alternative of using polymer insulators from China, which are resistant to pollutants, hence less prone to tripping.

Power Grid will be meeting Northern Grid constituent states, including Delhi, next month to sell the idea to them since the high cost will add to the cost of power supply.

Experts from the New Zealand-based company, Heliwings, have modified helicopters to fit a tank, a pump and a water cannon and also given a specially trained pilot for the cleaning job. State-owned Pawan Hans is a technology partner in the exercise.

“The high cost is its only minus point,” admitted Pankaj Kumar, Additional General Manager (Operations), Power Grid. “But as of now, India does not have the expertise to do this on its own.”

In north India, fog and air pollution from industry deposit on insulators and cause power lines to trip. Last March Northern Grid had tripped over two days chiefly due to this.

The technique involves spraying de-mineralised water (a bad conductor). Delhi Transco and other state transmission utilities have for long done this with jet pumps but Powergrid is the first to use helicopters.

“We cannot access all our towers by road because many are located in inaccessible areas,” said Bhaskar Sharma, GM, Operations and Management, Powergrid.

The complete dependence on foreign hands also adds to the cost. No Indian pilot is trained to operate the helicopter for this job. The New Zealand company can train them abroad, for a hefty fee. “If Indian pilots can operate this, we can cut the cost by a couple of crore rupees. But the cost may be recurring because pilots will have to be given refresher course every six months,” Vijay P Pathiyan, DGM (Engineering), Pawan Hans told HT.