These lights are currently selling well in Africa. How come? At 6pm every night when the sun goes down across sub-Saharan Africa, most off-grid households, of which there around 110 million in Africa, opt for burning dirty, dangerous kerosene lamps in their homes. Or if they can't afford that, they sit in the dark. That's obviously not conducive to productive working, safe cooking, socialising, studying or reading. Not only that, it costs lives. The kerosene lamp contributes to indoor air pollution that kills more people in
the world than malaria.
The S1 solar light costs around $7 and after that it's free to run. Solar Aid's goal is to banish kerosene lamps from Africa by 2020, freeing people from the need for dirty, expensive kerosene.
For more information on Solar Aid and their work see...