The electrical efficiency of a photovoltaic panel PV is highly dependent on its temperature. When the temperature of a PV increases, its electrical efficiency decreases. Using Phase Change Material PCM is one of the most promising tools nowadays to reduce and regulate the temperature of a PV panel and to increase its electrical efficiency. The current research is based on experimental studies of the effect of using pure (White petroleum jelly) and combined PCM (white petroleum jelly, copper, and graphite) on the thermal behavior and electrical performance of a PV panel. A transient energy balance is also presented to analyze the system thermal behavior and correlate it to the electrical outputs. To proceed, an appropriate experimental setup was devised and three prototypes were constructed and tested. Prototype 1 is formed from a reference case and consists of a stand, a PV panel, and an electrical circuit with a given load. Prototypes 2 and 3 are designed with a container added at the rear face of each PV panel that holds pure PCM and combined PCM respectively. It was shown that the electrical efficiency of PV panels has been increased by an average of 3% when using pure PCM and by an average of 5.8% when using combined PCM. These enhancements as well the corresponding behaviors were demonstrated by a transient energy balance approach. (C) 2017 Elsevier Ltd. All rights reserved.