SOLAR POWER AND LED LIGHTING -NEW OPPORTUNITIES FOR AFFORDABLE INDOOR LIGHTING OF RURAL FAMILIES IN 'BASE OF THE PYRAMID' CIRCUMSTANCES

摘要

Lighting, communication and water supply are generally considered to be the major domestic applications of solar electric systems in rural areas in developing countries. At present most solar powered lighting systems and solar lanterns use compact fluorescent lamps (CFLs). Current market prices and long-term technology roadmaps of light emitting diodes (LEDs) indicate that white LEDs might become a serious alternative for CFLs in solar lighting applications. LEDs have, more than CFLs, the opportunity to be applied in low-power indoor applications, making electric lighting affordable for a wider target group of poor families. Since solar powered LED lighting will be dominantly applied in a domestic setting, our paper focuses on human factors of lighting. It is argued that an acceptable minimum requirement for the illumination level of domestic lighting could be 30 Ix. For this reason a 1 watt LED connected to a small solar panel of typical 1 Wp could just provide enough electricity for three to four hours of lighting given the available solar irradiation in many developing countries. Such a small solar powered LED lamp including a rechargeable battery would have a retail price within the purchase power of families in circumstances of the "Base of the Pyramid". Our paper demonstrates new opportunities for affordable and mobile lighting systems and is illustrated by a conceptual design of an affordable solar powered LED lighting system for the case of rural Cambodia.