The ubiquitous Avon saleswomen traveled first by foot, then horse and buggy, and eventually by car to sell cosmetics door to door. In the process, the company built a global business that now earns ...

Solar day lamps (SDL) are simple and cost-effective. A few examples of SDLs have been described in [1], [2] and [3]. An SDL without any energy storage element suffers from frequent changes in the ...

In our second partnership with One Acre Fund, we’ll be following David and Zipporah, smallholder farmers from Kenya, for a whole growing season. From planting to harvest, we will check in every month ...

Most solar lights are cheap garbage that exist just to put more microplastics into the environment as they degrade in short order. [Jeremy Cook] built his own solar light, however, and this one might ...