In the absence of power, every night the air in the sprawling shanty-towns of India's cities fill with the dense smoke of kerosene used for lighting and cooking. For the slum-dwellers, the smoke is a killer - equivalent to consuming up to two packs of cigarettes a day. "We basically decided that if we wanted to solve this huge problem it had to be a business solution. You just can't give away 400 million lights", says Kat Kimmorley, co-founder of Pollinate Energy. Pollinate's simple and safe solution comes in the form of a portable solar-powered light, in which the poorest can invest in a brighter future. Their demand is now giving work to Indians like Latha, a young mother who sells the lamps to slum dwellers. "My status has increased. My life has changed", she says.