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Public Radio's Environmental News Magazine (follow us on Google News)

Light Up the World

Air Date: Week of

Dave Irvine-Halliday recently won an international award for using light-emitting diodes to bring light to homes throughout the developing world. He speaks with host Steve Curwood about his efforts.


CURWOOD: Worldwide, there are an estimated two billion people who don’t have access to lights. Their use of conventional lamps would require the construction of hundreds of new power plants. But one scientist in Calgary believes light emitting diodes can provide a far more efficient alternative. Dave Irvine-Halliday recently won the Rolex Award for Enterprise for bringing LED light to the developing world. He says the inspiration for the project came while he was hiking through Nepal.

IRVINE-HALLIDAY: There was a wee schoolhouse and I heard these children singing in the schoolhouse. So when I got down there, I popped my head in the window, which, of course, had no glass. And not only were there no children actually inside the school, but there were no tables, chairs, or teacher. And when I popped my head back out of the window, I noticed there was a lovely hand-painted sign above this window and it said ‘To you travelers, our children don’t have any regular teachers, and if you’d like to kind of stay around for a couple of days and help our children, we would really appreciate it.’

I think at that moment, everything sort of came together. Because when I poked my head in the window, my first thought was how dark it was. I don’t know. I honestly do not know why the thought suddenly struck me “Is there anything that I could do as a photonics engineer to bring light to these folk, at least help the children with their education?’

CURWOOD: Now why did you choose light-emitting diodes?

IRVINE-HALLIDAY: It just kind of struck me that if we were to produce light that was affordable and reliable and rugged, and also using very, very low power, we couldn’t go along the standard routes, in other words incandescent bulbs, or even the much more efficient compact fluorescent lights. And because I deal with diodes basically every day of my life, though it’s in kind of fiber optics, for some reason the thought just occurred to me ‘Well, why don’t we try LEDs?’

CURWOOD: Now, why not use compact fluorescents in these villages? Don’t they compare more favorably in efficiency to a white light light emitting diode?

IRVINE-HALLIDAY: I gave compact fluorescents a really deep look, but came to the conclusion that there was still approximately a ten to one difference in the amount of power or energy that I would need in order to light up a home to a useful level. This "useful,” the term "useful," I had to kind of find out myself. And when you find out how a light emitting diode actually emits its light, it emits it as a cone. You can actually direct it very efficiently to where you actually need the light to be, as opposed to lighting up the walls and the ceiling and the corners of the home. In a nutshell, the bottom line is you can light up a home to a very useful degree in the developing world, with a single watt of power. It’s a bit more difficult to do that with a compact fluorescent. It just came down to the energy requirements, plus the reliability, and the fact that LEDs live for literally decades.

CURWOOD: Wait a second, let me get this right. One watt of electricity is all you need to light up, say – effectively, that is – light up a single room where someone might want to read and work and live and cook?

IRVINE-HALLIDAY: When we realized you could read a book quite easily, even for eyes my age with point one of a watt, when you slap nine of these together and give yourself basically a one watt lamp – that was the original design – suddenly we could light up a, when I say a wee room, I mean a room maybe, you know, 10 by 10, or 10 by 14 feet.

CURWOOD: What are the power sources that you’ve been using for these lights? If it only takes a watt, how do you get that one watt?

IRVINE-HALLIDAY: We’ve done it in three ways. The first method was what we called the pedal generator. That pedal generator, which kind of pumped out effectively around 40 watts or whatever, it would charge up five of these small 12-volt batteries simultaneously.

The second method we used was very small hydropower. Thirdly, which is probably the way that we’re going to use mostly in the future, is good old solar power, solar photovoltaic cells.

CURWOOD: What stories have you been told? What have people told you about how all of this has affected their lives?

IRVINE-HALLIDAY: I think the first quote that really made a difference to me – in fact, when I say make a difference, it’s the kind of thing that it kind of chokes you up, there is no question about that. And that is when I was sitting chatting to a villager in the very first village that we lit, and this fellow turned to me and said a friend of his from another village had come up to see the lights. His friend had kind of remarked ‘A foreigner has come and made Tulapokera [phonetic] – that’s the name of the village – has made Tulapokera heaven.’ And it was such a simple, kind of right from the heart statement, that I couldn’t speak for a couple of minutes while I kind of absorbed it.

I think one of the other ones that has meant an awful lot to me and my colleagues was in Sri Lanka, and we just lit our first village there. It was actually about one o’clock in the morning, we happened to have been out visiting people. We were coming back through the jungle and we saw this light, and we recognized it immediately as one of ours. So we went over, and the father was still up. He opened the door and showed us the children who were all kind of lying on a mat on the floor. And he said ‘This is the first night in the entire life of all my five children that they’ve been able to read at night.’ It’s that kind of thing that, as I say, it kind of reduces you to tears almost, but if you ever needed a reason, which we don’t, that certainly gives you it.

CURWOOD: David Irvine-Halliday is director of the Light Up the World Foundation. He recently received the Rolex Award for Enterprise for his work to bring light to developing countries. Thanks for speaking with me today.

IRVINE-HALLIDAY: Thank you very much.

CURWOOD: For more information on light emitting diodes, go to our website. loe.org. That’s loe.org. You’re listening to NPR’s Living on Earth.



Light up the World Foundation

Rolex Awards for Enterprise


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