Water bottle brings light into the slums

A simple mix of water and chlorine is brightening homes in the Philippines.

‘Appropriate’ technologies such as the wind-up radio are all about clever devices that use less energy than their hi-tech equivalents, with the added benefits of being controlled by local people and easily replicable.

It’s incredibly rare to find examples of technologies that go further and negate the need for power altogether. But in the slums of Manila a device called the ‘Liter of Light’ [sic] is doing just that. The design – popularised by a YouTube video – is so brilliant in its simplicity it makes you gasp.

The Liter of Light uses discarded plastic drink bottles to bring light into dark slum homes, without the need for a single watt of electricity. The bottles are filled with water and a few spoonfuls of chlorine (to deter algae), and are cut into the corrugated iron roofs of shacks, where slum dwellers live in near darkness. It’s a highly appropriate technology for a country like the Philippines, where electricity supply is in many areas either unavailable, unreliable or prohibitively expensive.

The bottle doesn’t only let light in, but refracts it; on a sunny day, it provides as much light as a 50 watt bulb. At just £2, it takes an hour to install. The device was pioneered by the charity, MyShelter Foundation, which trains residents on how to make them, and the City of Manila government supported the scheme. The aim is to light up a million homes in the Philippines by 2012. – Charlotte Sankey

Photos: MyShelter Foundation