Sunlight in a bottle

A unique project is using plastic bottles to light up homes in Mumbai

For the last six-odd months, Akilesh Subramanian and Priyanka Bhosale, both in their 20s, have been lighting up lives in Mumbai through a global movement called 'Liter of Lights'.

Based on an idea that took off in the Philippines, Liter of Lights aims to provide an ecologically and economically sustainable source of light to underprivileged households. All that's needed to light up a room is a 1.5 litre PET bottle (like those made by soft drink companies), some water, liquid bleach, plastic sheets and a little bit of glue.

The process is simple. The group collects plastic bottles from shops, homes or neighbourhood clubs, fills them with water and bleach and sticks them with special glue through a corrugated plastic sheet similar to roofs of most makeshift houses. The glue takes a day to set. The bottle is then installed on the roof. Roughly one-fourth of the bottle remains above the roof and the rest of it hangs inside the house. When sunlight falls on the upper part of the bottle, water refracts the light and the bottle lights up. The light it emits is equivalent to that of a 55-watt bulb. The bleach is added to keep the water clean and to prevent algae from growing inside.

These lights have been installed in around a dozen houses in Back Bay, Santa Cruz, Reay Road and Worli. "There are thousands of houses in Mumbai where this technology can be used," says Subramanian. "However, these lights are most effective in houses that have no windows, but have direct access to sunlight. In case of a big room, multiple bottles can be installed."

A sturdy bottle lasts for five years, reducing the cost of the project. The only relatively expensive part is the glue which is made especially for the project in Germany. This industrial quality sealant helps in waterproofing the hole in the roof.

For the user, the cost of installing it is nil. But the 10-member team has to pay for travelling and sourcing material. The team has invested Rs 5,000-10,000 in the last three months and hopes to find some sponsors - Rs 500 can light up a home for five years.

The idea was pioneered by Alfredo Moser from Brazil in 2002. Then, in April 2011, Illac Diaz, the founder of MyShelter Foundation, launched the technology as a social enterprise in the Philippines. The movement came to India last year when a group of students from St Gallen (Switzerland) collaborated with students from Tata Institute of Social Sciences and Mumbai University.

"In October 2012, around nine students came from Switzerland to train us for two weeks. They hand-held us through the process," says Bhosale. "We thought it was urgently needed in a place like Mumbai, with so many clamped slums everywhere. And this was, after all, a direct way to help someone."

The group now holds regular workshops in and around Mumbai to spread the word and teach volunteers how to use this in their own communities. It have also tied up with two NGOs - LEARN or Labour, Education and Research Network which works on women's upliftment, and Sankaar India Foundation, which works for children's education.

"Since we installed the lights in this locality, families have reduced the use of electricity 50 to 70 per cent. Now, there is no need to use electricity from, say 9 am to 4 pm," says Omkar Phadke, a volunteer who helped install these lights in a two-room house belonging to a family in Nashik. The family, having attended a workshop organised by Liter of Lights, can, in turn, help its community do the same.

Liter of Lights is so far present in Mumbai and Nashik and plans to enter Uttar Pradesh soon. The aim is to spread the word and encourage more people to come forward to help - one bottle at a time.