This paper introduces an analysis and calculation method to determine voltage bands, which are voltage regions of possible global maximum power points (GMPPs) for stand-alone photovoltaic (PV) systems under non-uniform irradiance conditions. Non-repeated irradiance cases is analyzed to obtain GMPPs according to electrical characteristics of a series-parallel-connected PV array. A clustering method is used to process these points to build voltage bands. Slope coefficients compensate for the influence of the temperature. Simulation results shows the influence of the PV array configuration and the PV module type on the voltage band method. The proposed method can be applied in designing global maximum power point tracking methods and analyzing the approximate regions of GMPPs. (C) 2017 Elsevier Ltd. All rights reserved.