In this paper, theoretical and experimental study of the performance enhancement of PV panels has been presented by utilizing fins for cooling module’s temperature at climate conditions operation. To satisfactory cool off for the solar panel as a passive technique, heat sink which has a rectangular variable cross section fins (ribs) attached on the back side of the panel. Analytical thermal model is formulated for heat dissipation from heat sink in order to predict PV panel temperature. A comparison between experimental and theoretical results was carried out for solar panels without and with fins, in order to investigate the proposed thermal model and study the effect of operating temperature on the power output from the panel. The results shows that using fin cooling technique causes a significant dropped in average solar panel temperature about 5.7°C and an enhancement in the average of module output power about 15.3%.