Technical Standards for Solar Home Systems (SHS)

Field experience with PV rural electrification has shown that the performance of solar home systems SHSs is not always entirely satisfactory. However, in-depth studies of the problems encountered in existing installations have revealed that the pure solar part, i.e. the PV generator, rarely fails. The PV system is often initially blamed for the failure but, when things go wrong, it is usually the other PV system components or the appliances which are powered by the PV generator which are found to have failed. This is mainly because, while PV modules are highly standardised and certified using internationally validated procedures, there are no equivalent standards and procedures available for balance-of-system components, component matching or installation quality, even though the quality of these components has a dramatic influence on user satisfaction and operating costs.

Source: Universal technical standard for solar home systems, Version 2, Thermie B SUP 995-96, EC-DGXVII, 1998, updated in 2001.

The "Instituto de Energía Solar" at the "Universidad Politécnica de Madrid" prepared a report that is designed to form the basis for a Universal Standard for SHS. It is based on a world-wide review of existing technical standards for SHSs (see Annex 1), which has revealed a large number of inconsistencies¹ between these standards. In particular, different approaches have been found for system sizing, and for specifying types of PV modules, the number of cells in PV modules, types of battery, charge regulation voltage set points, operational information for users, voltage drops, safety measurements and ballast, cables and connectors requirements.

[1] "Systematic comparison of SHSs existing standards". IES Internal Report. 1997