Partial shading is a commonly encountered mismatch problem in a photovoltaic system. In the drawing near perspective of their massive building integration, dye solar cell (DSC) modules may realistically receive different levels of irradiance, a situation similar to partial shading. In these conditions, the electrical characteristics of the DSC module significantly change. Here a general model for the description and the analysis of dye solar generators is proposed. A new equivalent circuit for DSCs has been developed that is characterized by the introduction of a second diode, capable to conveniently take into account the behavior of the reverse-biased cell/s. An experimental demonstration of the proposed two-diode model's validity is provided. A detailed description, based on numerical analysis, of the influence of partial shading on the photovoltaic performances of a DSC module made by four W-connected cells is given. We here demonstrate that the implementation of a two-diode model allows an excellent matching between the experimentally measured I–V characteristics of the partially shaded module and the simulated ones. Copyright © 2012 John Wiley & Sons, Ltd.