Sunlight in streetlamps?

One option

The KMC pays a mammoth Rs 3.5 crore every month for the 1,27,000 streetlights installed in the various wards across the city. Of late, the civic body has become open to the idea of using renewable energy in lighting up city streets. But it is also aware that the options are few and far between — wind energy was ruled out as strong winds are not a geographical characteristic of Kolkata. “The only option we have is to use solar energy for illuminating the streets,” said KMC’s Chief Lighting Engineer Pradip Jyoti Biswas.

With roads making up only seven per cent of the city’s total area, streetlights cannot be switched off at night, as is the practice in some of the world’s busiest streets.

Further, most heavy vehicles ply at night and switching off would impede their journey.

Generally, sodium vapour lamps and fluorescent bulbs are used in street lighting. On an average, there is a 3 to 5 per cent hike in power bills every year and with the inclusion of more areas in the civic body’s jurisdiction, its bills are likely to go increase further. The department is keen on using the solar lighting terminus as an alternative means of lighting.

About 100 solar lamps are operating in a 1-km stretch in Khanaberia near the Dhapa dumping ground. Streetlights powered by solar energy have operated in South Dum Dum area.

The KMC will soon start monitoring the results officially.

Problems

The corporation believes that there are some problems hindering widespread use of solar panels. For one, the cost of installation is huge. The corporation is also sceptical that whether the wattage required to light streets can be provided by solar energy.

The pole-height is quite low and this can create some problems when it comes to illuminating a larger patch of area. The solar panels above the lamppost are weak and might not survive inclement weather.

The surface of the panels will have to be cleaned properly and kept dust-free, as dust is a bad conductor of heat and will prevent the panels from harnessing energy adequately.

WBREDA optimistic

The West Bengal Renewable Energy Development Authority (WBREDA), which is the agency involved in the production and facilitation of alternative sources of energy, including solar light panels, feels that the civic body can save a lot of money if solar energy is used.

WBREDA has introduced two types of lamps — coal cathode lamp and sodium vapour lamp — which can used for street lighting.

“Other than KMC, the KMDA has also been asked to use around 500 lamps in many areas,” said WBREDA secretary S P Gonchowdhury.

The cost of setting up a solar lamp is about Rs 50,000 while installing an ordinary light is about Rs 30,000. The overall cost of an ordinary light during its life period is Rs 80,000, he added.