Solar home systems (SHSs) are being promoted worldwide as an option for permitting access to some of the benefits of electricity by households not served by the existing electricity grid.

A SHS is comprised of a solar photovoltaic (PV) panel which generates electricity from sunlight (the blue unit mounted above the roof of the home shown in the photograph below), a battery which stores the energy generated during the day primarily for use during the night, lights, and some electronics to ensure efficient operation of all these components together. Energy stored in the battery is also commonly used to power radios and small televisions.

A homestead on the high Bolivian Altiplano relying 
on solar energy to provide basic lighting. 

While the use of photovoltaic (solar) modules is being promoted as a technology which is ready to meet the need for electricity in rural areas in developing countries, heavy promotion by manufacturers in the West makes it easy to overlook some of the real issues facing the implementation of this technology: its capital and recurring cost and reliability of the overall package over its life. Although these issues are commonly overlooked in the general literature, an awareness of them is critical if one is interested in ensuring a cost-effective investment (i.e., not subsidized) in this technology.

For a typical 50 Wp system, equipment cost begins at $500 per unit and can be significantly more. Recurring costs for the battery alone can run $2-3 per month which is, in itself, a significant sum for many of the "two billion people without access to electricity". Furthermore, experience has shown that without regular visits by a trained technician, systems life can be considerably reduced.

These issues are probed further in the publication "Challenges to implementing sustainable PV solar home programs" available from NRECA. This publication also reviews some costs claimed by implementers of SHS projects around the world and compares this with the real cost of this technology.

It is only by increasing one's awareness of the issues behind the implementation of this technology that suitable applications can be found. Only then is there any chance for this technology to be a sustainable solution for providing basic electricity to rural people, a solution which will truely be replicable.

(Revised June 21, 1997)