This paper presents a new maximum power point tracking algorithm for PV systems useful in case of non-uniform irradiance conditions. This algorithm takes into account the number of bypass diodes in a PV string to calculate the voltage bands associated with the peak power points that appear in the power voltage characteristic of the PV system. The main contribution of this study is to state that the global maximum power point can be tracked by considering only the possible voltage bands which can be found by using the proposed analytical equation in a simple manner. The algorithm is based in the evaluation and analysis of these voltage bands and in the selection of the PV system voltage related to the maximum power point of work. The proposed algorithm has been validated by means of simulation and also in an experimental study. (C) 2013 Elsevier Ltd. All rights reserved.