The Sun was yet to go down. But darkness had already descended in most of the shanties lining the narrow dingy lanes of Lal Bagh slum near Azadpur in north Delhi.
Because of poor ventilation, sunlight doesn’t enter most of these shanties and the families have to either remain in dark or switch on the bulbs and tubelights even during daytime.
But over the past two years a simple innovation known as the Micro Solar Dome (MSD) — a device that can capture sunlight and concentrate it in a gloomy room — has transformed the lives of around 130 families in the same slum.
“Now we don’t have to switch on the light bulbs during the day. It helps us save at least Rs 50-100 per month. With just one member earning around Rs 6,500-7,000 and five mouths to feed, this is a good amount to save,” said Seema, a slum dweller.
The MSD is a day and night lighting single device, which has a transparent semi-spherical upper dome made of acrylic material that captures the sunlight. The light passes through a sun-tube that has a thin layer of highly reflective coating on the inner wall of the passage. It also contains a lower dome made of acrylic. There is a shutter at the bottom of the lower dome which can be closed if light is not required during the day. Fitted with photo-voltaic solar panels, the MSD can work for four hours after sunset.
Dev Kumar, a Class 2 student of a local school, ran up the dark and steep stairs of a two-storeyed building where his friends had gathered like any other day. Around 30 children sat huddled up in a small room measuring around 6 feet by 6 feet. They had all come for tuitions.
“Two years back I had to rely on electricity. I had to pay the electricity bill as well as bear the heat as the small room used to get heated up very quickly. However, with the installation of solar dome, I can feel the difference — the amount of light has increased and the electricity bill has dropped. The children can now study in a better illuminated room,” said Sonu Kumar, who gives tuitions to around 60 schoolchildren.
“Earlier, we had to study in the dimly-lit room as it was not possible to keep the lights switched on during the day. But now we can at least study properly,” said Jahnvi, a Class 8 student of a local girls school.
A pet project of Union science and technology minister Harsh Vardhan a few such MSDs were installed in Lal Bagh slum in April 2016 by the department of science and technology. Buoyed by their initial success, more such devices were installed in 2017.
“These domes are easy to maintain, costs around Rs1,400 and has a huge potential in both rural and urban areas where there’s no electricity, or in slums where rooms remain dark due to poor ventilation. Around 25,000 such domes have been installed in the slums of Kolkata, Delhi, Pune, Bhopal and Agartala among others,” said SP Gon Chaudhuri, a scientist from Kolkata who invented the dome.
Gon Chaudhuri has trained a local electrician from Azadpur, who maintains these solar domes.
“These solar domes have a life of at least 10 years. It just requires some dusting. The dust of Delhi settles on the dome and solar panels which creates problem. But unlike rooftop solar panels, which help to run not just lights but even fans and televisions, solar domes are just for producing light,” said Gulab, the electrician.
At present, only two companies — one based in Kolkata and another based in Mumbai — are manufacturing these domes. A senior official in the department of science and technology said that there are plans to scale up the manufacturing not only to reach more customers but also to bring down its cost further.