In 1996 Canadian professor David Irvine-Halliday was on a work trip in Nepal when his return flight was canceled. It would be weeks before he could catch another flight home, but the delay gave him time to hike the Annapurna Circuit, a 14-day trek through the Himalayas. One day, wandering past a school he heard children singing. He looked in the window and wondered how, without light, the kids could study. Sadly, he realized, these conditions are common in poor countries. Some 1.6 billion people in the world have no access to electricity.
People who aren't connected to the electric grid often get their light from kerosene, candles or burning wood. But, the products are expensive, produce only dim light and generate polluting fumes that cause health and environmental problems. Responding to the need for safe, clean and affordable lighting, Irvine-Halliday set to work on a solution.
LEDs turn out to be a bright idea
Back in his laboratory at the University of Calgary, Alberta, he experimented with light emitting diodes, technology he was familiar with as a professor of renewable energy. "I knew that they were virtually indestructible. They lasted for decades because they were putting them under the Pacific and Atlantic Oceans, and they were going to be there for years and years and years working for 24 hours a day," he says.
Irvine-Halliday settled on a one watt bright white light, a Japanese product he discovered on the Internet. Startled by the intense beam he generated when he rigged the diode to his bike generator, he recalls saying to his partner, "Good God, a child could read by the light of a single diode."