Designing affordable solar lighting: Energy-efficient LED design reduces payback to 5 months for Zambian customers

The economic, health, and environmental costs of kerosene, candles, and other fuel-based lighting are well-documented. As a result of efforts by the World Bank and other organizations, a new category of solar-powered lighting, the solar portable light, is being promoted as a more affordable alternative to fuel-based lighting. This paper uses the UC Davis Lighting the Way Zambia project as a case study to understand the minimum manufacturing costs of an affordable solar portable light. The study examines functional preferences of users in Zambia, translates these into performance requirements, and then determines the cost implications for those requirements. The results suggest that an 18-lumen solar portable light with a 4-hour run time would meet many users' needs, and could be manufactured for approximately US...