Hybrid PV/Thermal systems (PV/T) are proposed to harvest the two renewable forms of solar energy, electrical and thermal. The use of PV/T systems improves electrical efficiency while utilizing the available solar thermal energy for various heating applications. In this work, numerical simulations perform for PV/T system in hot climate conditions. The cooling system consists of eleven channels arranged in parallel to each other on the backside of the PV module. A novel three-dimensional numerical model of the PV/T system was developed to evaluate the thermal efficiency. The standard k – epsilon model was used to simulate the flow. This novel system was based on using symmetric- convection boundary conditions for the right and left sides of the PV/T model and symmetric-symmetric boundary conditions for the middle cooling channels rather than simulating the whole cooling system. Using one channel simulation allows the creation of less number of meshes, hence, reduces the computational time. The thermal efficiency was estimated by the superposition method for all cooling channels of the PV/T system. The thermal efficiency of the PV/T system was 60% at 0.4 (L/min) and 68% at 5.4 (L/min). The obtained results were in good agreement with the results presented in the literature.