POWER PLUS: Streetlights form a glowing canopy over Red Road. A Telegraph picture

The civic body is turning to technology to cut down on power bills.

An invention by a city-based scientist and compact fluorescent lamps (CFL) are two of the options being considered by the Calcutta Municipal Corporation (CMC) to increase the longevity of street lamps and reduce power consumption.

The CMC spends over Rs 30 crore annually on street lighting. The power bill in its various offices amounts to Rs 120 crore per year.

An “ignitor” — invented by Dhanonjoy Biswas, a scientist at the CTBL Electronics Regional Testing Laboratory (East) — has the potential to extend the lives of sodium vapour and metal halide lamps, thus curtailing the CMC’s expenditure on power, said H.K. Majumdar, the working chairman of the West Bengal State Council of Science and Technology.

“A high-energy, high-amplitude pulse is required to switch on a light. This pulse, referred to as critical energy, causes erosion of the electrode, leading to reduction in light output and life span of the bulb,” said Biswas.

According to him, the ignitor helps to contain the energy in the pulse, preventing decay of the electrodes. “The light output will also not be affected. Hence, bulbs of lower wattage can be used, saving up to 33 per cent energy.”

Majumdar said: “We had recommended the project to the chief minister, who is the chairman of the council, and he has granted permission to conduct a pilot project.” Biswas has been asked to submit a proposal for the one-year project.

“We would be keen to take the project forward,” said the civic chief engineer (lighting), Pradipjyoti Biswas.

The civic authorities are also using CFLs as street lamps on an experimental basis in Sealdah. A CFL consumes one-fourth the electricity of an ordinary bulb. According to an estimate, the CMC will save around Rs 6.5 crore if 40 per cent of the street lamps are replaced with CFLs.