In this paper a novel explicit model is proposed to represent I-V expression of conventional double-diode model for photovoltaic (PV) cells. This model is based on two rules in electronics: first, Thevenin's theorem to describe the linear components of equivalent circuit of PV cells, and second piecewise linear (PWL) model to approximate the behavior of remained nonlinear part. Defining a new parameter (a), an approximate explicit solution for I-V curve of PV model is extracted which surpasses conventional implicit model due to its high computational efficiency particularly in repetitive simulation of PV fields. Dispensing any need to change the concept and consequently the values of conventional double-diode parameters, only single new translation equation is developed for the parameter (a) in wide environmental conditions, which reduces the model complexity in comparison with other reported double diode explicit solutions. The suitability of the proposed model would be thoroughly accredited by circuit analysis, experimental data and extensive simulation studies. (C) 2016 Elsevier Ltd. All rights reserved.