For household applications in developing countries there are numerous lighting options covering a wide range of lumen output levels, energy consumption, and costs.
But many technically feasible alternatives for household lighting are not commercially available in developing countries. Consumers in rural areas, in particular, have very few choices of lamps.
One reason is that lamp manufacturers do not appreciate the potential of the rural lamp market and believe it is too small for more efficient low-wattage lights.
Field surveys have demonstrated, to the contrary, that a wider spectrum of lights, particularly in the low power range (1-10 watts), would better meet the cost and quality criteria of many rural customers. This applies both for photovoltaic installations and for rechargeable (car) batteries.