Alfredo Moser had a light-bulb moment and came up with a way of illuminating his house during the day without electricity using nothing more than plastic bottles filled with water and a tiny bit of bleach.
The inspiration for the "Moser lamp" came to him during one of the country's frequent electricity blackouts in 2002. "The only places that had energy were the factories - not people's houses," he says, talking about the city where he lives, Uberaba, in southern Brazil.
Moser and his friends began to wonder how they would raise the alarm, in case of an emergency, such as a small plane coming down, imagining a situation in which they had no matches.
His boss at the time suggested getting a discarded plastic bottle, filling it with water and using it as a lens to focus the sun's rays on dry grass. That way one could start a fire, as a signal to rescuers. This idea stuck in Moser's head. He started playing around, filling up bottles and making circles of refracted light.
Soon he had developed the lamp. "I didn't make any design drawings," he says. "It's divine light. God gave the sun to everyone, and light is for everyone. Whoever wants it saves money. You can't get an electric shock from it, and it doesn't cost a penny." Moser has installed the bottle lamps in neighbors' houses and the local supermarket.
While he does earn a few dollars installing them, it's obvious from his simple house and his 1974 car that his invention hasn't made him wealthy. What it has given him is a great sense of pride.
Following the Moser method, MyShelter started making the lamps in June 2011. They now train people to create and install the bottles, to earn a small income. In the Philippines, where a quarter of the population lives below the poverty line, and electricity is unusually expensive, the idea has really taken off, with Moser lamps now fitted in 140,000 homes.