Lighting Up the World, One LED at a Time

Monday, July 28, 2003

VICTORIA -- David Green dreamed of an anchor light that would not drain his limited battery power as he sailed from Fiji back to Victoria at the end of a five-year cruise.

David Irvine-Halliday peered into a dim schoolroom while trekking in Nepal and wondered how he could light the dark corners in a village with no electricity.

Green was looking for a new business opportunity. Irvine- Halliday was looking for a way to overcome seemingly insurmountable obstacles to bringing light to an impoverished country.

The two Canadian engineers found their solutions in the same rapidly developing technology that is being hailed as the biggest breakthrough in lighting since Thomas Edison invented the light bulb more than a century ago.

Light emitting diodes -- LEDs -- have been around for decades. In the past few years, however, researchers have learned how to crank up their power to the point where they provide usable light for a fraction of the energy consumed by existing sources.

Just as importantly, they have finally found a way to create diodes that emit white light, which has been the holy grail of LED researchers for more than two decades.

For the developing world, the new bright LEDs carry the promise of light for the more than 1.5 billion people without electricity.

For British Columbians and other North Americans, the potential is for huge savings in energy consumption. About 20 per cent of all electricity produced goes into lighting.

Irvine-Halliday, a professor of electrical engineering, had his eureka moment in his darkened laboratory at the University of Calgary. He connected a battery to one of the first LEDs to produce white light, an LED that consumed one tenth of a watt.

"We set it up about 18 inches above the desk and we had a sheet of typed paper underneath. When that light came on, you talk about you see the light, it was really a pivotal moment."

He said to his colleague, "good God John, a child could read with a single diode -- I mean, point one of a watt."

Irvine-Halliday started a foundation, Light up the World, and developed a light system that used six diodes and consumed about one watt of electricity.

"It was what I referred to as a very useful amount of light. It was not as much as we would have liked, but it was as much as we could afford."

The fact that the diodes produced enough light to read by with only one watt of electricity solved the real problem in lighting remote villages, which is generating the power needed to energize the lights.

An impossible cost for poor villagers suddenly became a manageable cost -- now about $60 per household for a system with a single light.

A group at Stanford University has been working on systems to bring that cost down even lower, since it still represents a significant barrier in countries like Nepal.

Irvine-Halliday powered the lights with a rechargeable battery, which can be recharged by a pedal-powered generator, solar panels or a minute water power system.

The amount of light produced by one of the systems would not be noticed in a North American house, but in a dwelling lit previously only by a smoky kerosene wick lamp, the impact is immense, says Halliday, who has since distributed more than 1,000 such systems through his foundation, which can be visited on-line at

"Because of the remoteness of many of these villages, many of them would not have seen any kind of electric lighting." Green was less successful in his first attempts to create an anchor light using LEDs in 1994.

At that point, there were no LEDs that produced white light and the yellow LED he tried could not be seen for anywhere near the required distance of about three kilometres.

"It was pathetic," he recalls in an interview in the office of Carmanah Technologies, the company he founded in Victoria.

But Green and his partner persevered and the growth of his company, which now manufactures self-contained solar-powered lights for marine, rail, aviation and transit systems, mirrors the growth of the development of the LEDs they use in their systems.

Carmanah's sales have been growing at an annual rate of 75 per cent a year for the past five years. They have mined markets where light is needed in places where power is difficult or impossible to obtain -- on ocean buoys, for example -- places where the high cost of production in Victoria is less important than the rugged reliability of their products.

Like Irvine-Halliday, Green also found a niche where the efficiency of LEDs is important because power is a scarce commodity.

But the real growth potential of LEDs is in the markets of the world that are already awash in light from conventional sources.

Multinational corporations like Philips and General Electric are investing millions in a race for a multi-billion dollar prize.

"It's huge," says Irvine-Halliday.

"You don't have to be a rocket scientist. Once you see the light in a darkened room from a one-watt lamp and realize, okay, to light up the world, energy is worth its weight in gold."

"To the overdeveloped world, we can afford to spend a little bit more on energy, so you can say, 'Well, what about 10 watts?' All of a sudden, with 10 watts in a bulb or even a little less, you've got a heck of a lot of light."

Green says the development of LEDs has followed Moore's Law, which was coined by Gordon Moore, one of the founders of the computer chip maker Intel Corporation.

"Every year-and-a-half they were half the cost and twice the power."

Evan Mills, a researcher in the Environmental Energy Technologies Division at the Lawrence Berkeley Labs in California, says the advances are still being made on a steep curve.

"The first generation of white LEDs were maybe something like one lumen `a measurement of light` per watt. Now the things that everybody has on their key chains are five lumens per watt and the best on the market are about 25 lumens per watt. That's an incredible multiplier."

LEDs were first developed in the early '60s, when scientists discovered they could persuade certain kinds of semi-conductors to produce light. The colour of light varied, depending on the material.

The light was very dim, however, so the new light emitting diodes were used primarily as indicator lights in electronic equipment.

In the early '90s, when researchers learned how to create much brighter lights, LEDs became a lot more useful and started showing up in some consumer products, including bicycle lights and flashlights.

They also figured out some tricks to approximate white light. White, while the most useful, is a problem because it is not really a colour but a combination of colours.

One major advantage of LEDs over conventional lights is that they produce very little heat. Ordinary incandescent light bulbs convert as much as 95 per cent of the electricity they consume into heat.

They are also extremely durable, since they are encased in solid plastic and they can last for five years or more.

They are still very expensive, however, relative to other light sources.

That has made them most attractive so far for uses where reliability is crucial or the cost of replacing bulbs is very high.

B.C. Hydro has been promoting the use of LEDs as part of its Power Smart program. The most visible sign of that is the stoplight replacement program. Hydro estimates that replacing the lights in Vancouver alone will save the city an estimated $350,000 in energy and maintenance costs.

The white LEDs are now bright enough that automakers are looking at designs incorporating them as front headlights, but the real breakthrough this year is in the rapidly growing availability of spot and mood lighting.

It will likely still be several years before the price falls far enough to make them attractive to consumers for general household illumination.

But they could appear more quickly than that if the snowball effect of falling prices increases demand and the increasing demand leads to lower cost production.

Green and others point out, however, that other technologies are fighting back.

He notes that compact florescent bulbs, which are also energy efficient, have also been improving over the past few years.

"It is a battle. In terms of general illumination, I don't think it's clear yet that LEDs are going to win."