The purpose of this work is to: 1) improve a previously developed behavioural model (B-model) for photovoltaic modules and 2) validate it using experimental data. The major advantages of the new model are its simplicity and the fact that it is based only on the module's electrical properties available on the manufacturer's datasheet. At first, the original model was developed and validated using a rich experimental database solely for a polycrystalline silicon photovoltaic module. However, an improved version of this model along with validation tests which use a larger database is presented in this paper. The larger database utilises the measured I-V characteristics of three other photovoltaic technologies such as, monocrystalline silicon, CIS and CdTe. To permit a sound and relatively easy entry into the study of photovoltaic for novices and newcomers, a detailed flowchart and description of its use are presented. Also a concrete example of an application using the flowchart is presented to display its efficiency and ease of use. (C) 2014 Elsevier B.V. All rights reserved.