In this paper, we study by numerical simulation, the cooling of a solar photovoltaic panel using a nanofluid as a cooler. The solar panel is subjected to a hot temperature that character-ises the climate of the city of Bechar located in southwestern Algeria. The nanofluid (Al2O3-water) is introduced in the cavity with a constant horizontal speed and subjected to the ambient (cold) temperature. The equations governing the hydrodynamics of the flow and the heat transfer are described by the Navier-Stockes and energy equations. The finite element method is used to solve the system of partial differential equations (PDEs) based on the Galerkin method. We consider the effect of solid volume fraction and form factor for different values of Reynolds number on the results in the form of isotherms, streamlines, temperature, velocity, average Nusselt numbers and solar panel efficiency.