A Review of Solid State White Light Emitting Diode and Its Potentials for Replacing Conventional Lighting Technologies in Developing Countries

Lighting is an indispensable energy end use of man. A significant number people in developing countries live without electric lighting and depend on oil-based lamps. Globally, lighting consumes substantial amount of energy and is a major contributor to green house emissions. Conventional electric lighting systems such as incandescent lamps are highly inefficient and waste energy while the fluorescent/CFL lamps contain toxic chemicals like mercury. Incandescent lamps with short lifespan as well as the fluorescent/CFL lamps pose environmental waste disposal problems (e.g.). The use of renewable energy resource such as solar and wind power systems for example as sources of power for the most efficient and long life lighting source such as high-brightness light emitting diodes (LEDs) (also known as solid state lighting) would reduce global energy consumption for lighting by half, with corresponding reduction in green house emissions. In developing countries solar powered solid state lighting (SPSSL) would ensure access to electric lighting by the disperse population who may not be connected to the national grid in the near feature. In this article we elaborately review the upcoming solid state lighting technology. The physics and principles of operation of LEDs are also reviewed. The impact of this new lighting technology on developing countries in the areas of commerce, education, health and environmental impacts in comparison to conventional lighting technologies is the main thrust of this review