This paper presents the experimental results and discusses the track of the maximum power point on the current-voltage curve of a PV module due to changes of the illumination level and temperature. A time decrease of the voltage and simultaneous temperature increase during the initial stage of irradiation has been observed. Some practical implementation aspects of a maximum power point tracking unit, which match the current and voltage characteristics of the load to the PV module's maximum power point automatically, are also discussed. A linear decrease of the maximum output power P-m with temperature increase has been observed and the temperature coefficient was derivate. Temperature coefficients for V-oc, I-sc, V-mpp, I-mpp, and eta(PV) have been determined for the photovoltaic module. Also the radiation rate coefficient at constant temperature has been calculated.