“I love to recycle”, a smiling Illac Diaz told the assembled crowd at TEDx Dubai late last year. Diaz took to the stage to explain how his MyShelter Foundation is encouraging a low-cost green revolution in the Philippines. “We all know why we have to recycle. Something that we consume for a few minutes – an hour maybe – takes a long time to get rid of... This especially in a country such as ours, which is an archipelago, 7,100 islands. When the plastics and the bottles come into the islands, there’s very few reasons for it to go out, so either they bury it or sometimes they just put it out into the sea and it just floats away.”

Diaz’s small NGO started looking at ways to change the world in a big way with very little money. The financial constraints led Diaz to look in some unusual places and eventually he realised that “a great big problem could be the biggest solution”. So, Diaz and his colleagues “got all the bottles we could out of the junkyards” and started putting them to good use. Initial projects to build schools out of plastic bottles filled with soil have led on to a project with the aim of changing “everything for people that are living in darkness”. And so the ‘Isang Litron Liwanag’ (A Litre of Light) project was born.

Using bottles to let light through roofs in overcrowded areas is nothing new, but traditionally people used glass bottles. A few years ago, a man called Alfredo Moser began experimenting with plastic bottles in Brazil, and MyShelter had students at the Massachusetts Institute of Technology develop the idea for use in the Philippines.

The process for making a solar bulb is simple: a hole is cut into a square of galvanised iron (corrugated or flat, depending on the roof it is to go in), and a clear, 1.5-litre plastic soft drink bottle is placed perpendicularly inside it and fixed in with rubber sealant. Next, the bottle is filled with purified water (as tap water would allow moss to grow) and approximately 10 millilitres of bleach. After tightly sealing the cap, the bulb is ready for action. It can replace iron in the roof of a home (making sure it is securely inserted so as not to allow leaks), and during the day, the sunlight refracting through the water produces light equivalent to a 55-watt bulb – enough to brighten up a 35 square metre room. According to Diaz, the bulbs will last up to 10 years.

Last April, the first solar bulbs were installed in the impoverished Tondo area of Manila, and since then, more than 200,000 have been fitted in homes in more than 20 cities across the Philippines. The project aims to hit the million mark by the end of 2012.

The Isang Litrong Liwanag project was developed in accordance with the principles of ‘appropriate technology’, first put forward in EF Schumacher’s Small is Beautiful, and roughly defined as a technology that is small-scale, labour intensive, environmentally sound and locally controlled, as well as ‘people centred’. Diaz explains: “Basically, what we wanted to do was not have everything pass through us to change other people’s lives, but maybe give them technologies that they could do themselves, which would make us obsolete. Another thing we did is to try to look for something that would [go] viral, that would change everything for people that are living in darkness.”

So, instead of going around and installing all of the lights themselves, the folks at MyShelter teach locals in different areas of the Philippines how to make the bulbs, and then these locals are able to start a business installing lights for their neighbours. One man, known as ‘Solar Demi’, has personally produced and installed more than 8,000 bulbs, utterly transforming his community. The plastic bottles are found locally and the skills required are basic, so, in theory, anyone can produce and install a bottle in the Philippines for approximately 150 Philippine pesos (£2), a one-off sum that compares quite favourably with the equivalent £6 a month that would otherwise be spent on electricity.

In addition to financial savings, the solar lights also increase the body’s production of vitamin D, which is useful in preventing rickets and generally improving bone health. They also substantially decrease the risk of fires – both from the open flames and faulty electrical connections, which are common in poor areas as the Philippine’s Bureau of Fire Protection (BFP) does not conduct fire hazard inspections in what it terms ‘informal settlements’.

Unsurprisingly, the reactions from residents who are benefitting from solar lights has been incredibly positive, with one resident featured in a promotional video for the project noting: “We used to take this bottle for granted. Now, we can’t live without it.” Indeed, as Diaz concludes: “The best thing is... they will never go back into darkness... We start out dark. People live in these kind of conditions – inhuman sometimes – but in 10 minutes we brighten their world.”