Photovoltaic (PV) energy is an alternative energy source for the future due to the world's limited energy resources. In this paper, a new technique to improve the performance of a PV array is presented. The study is based on the determination of the optimal configuration of a PV generator for a fixed number of modules. The aim of the study is to extract the maximum power from a PV generator connected in a direct coupling to a load. Different considerations (commutation current alone, commutation voltage alone, commutation current and voltage) are described. The presented method is based on microcontroller utilization. Very simple calculations allowed to decide, in real time, which configuration is appropriate for any load and any work conditions. Theoretical and experimental results are included. The effectiveness of the applied method is assessed by simulations and experiments. The method using commutation current and commutation voltage leads to good results unlike the other techniques. Copyright (c) 2008 John Wiley & Sons, Ltd.