The dissemination of small solar photovoltaic systems in developing countries has been promoted for more than four decades with various successes.  At the beginning, they were expensive and were used only to power small loads in remote areas.

The considerable decrease in the price of solar combined with technological innovations has led to a sustained growth and diversification of the off-grid solar market. The advent of mobile technologies enables now the remote managing of a very large number of small systems. The use of systems has also diversified with reliable small systems like solar lanterns which can also be used to charge a mobile phone. These systems can now be found even in on-grid areas as back-up systems to an unreliable grid.

There is a growing field of research currently available on the impact of small solar systems contradicts the commonly accepted idea that these small solar systems–due to their limited capacity–cannot have an impact in terms of development. In actual fact, as explored in a review article in WIREs Energy and Environment, these systems seem to have a significant impact in terms of quality of life for their users and in helping them to keep connected to the global world.

For instance, solar lanterns contribute to substantial financial savings and reduce the time spent in solving energy supply issues for lighting.  They provide better lighting than petroleum lanterns, which improves studying conditions for children in schools and at home.  Better lighting also helps women (and men) to do more activities at home.

Solar home systems’ impact is more complex to apprehend as–on top of the impact of better lighting–they can for instance power a radio and a TV which provide entertainment, but also access to information, and therefore have an impact on education and health.   Nevertheless the latest impact needs to be evaluated in the long-term by more in-depth research.

Kindly contributed by Dr Xavier Lemaire, University College London, Energy Institute.