When the sun goes down on almost 1.3 billion people around the world, the only respite from the darkness is fire. These are the people who have no access to electricity. If children want to study, or adults want to remain productive, or families want to sit and talk, most must do it by light of a flame.
But light sources like wood, candles, or hydrocarbons like kerosene oil, which was burnt at the rate of 38.7 million gallons a day in 2010, are far from the best solution. Combustion is dirty, releases toxic chemicals and can be expensive.
“A fifth of the world’s population earns on the order of $1 per day and lacks access to grid electricity,” wrote Evan Mills, a Lawrence Berkeley National Lab staff scientist, in the 2012 technical report Health Impacts of Fuel-Based Lighting. “They pay a far higher proportion of their income for illumination than those in wealthy countries, obtaining light with fuel-based sources, primarily kerosene lanterns. The same population experiences adverse health and safety risks from these same lighting fuels.”