In the last decade, no comprehensive numerical and experimental analyses have been performed to find the maximum possible power generation from a concentrated photovoltaic thermal (CPV/T) system by varying the flow rate of the fluid. This paper describes numerical and experimental studies of a U-shaped solar energy collector model of a CPV/T system, with the goal of determining the maximal thermal and electrical power outputs against a specific volumetric flow rate also called an optimum flow rate. The CPV/T system was based on the union of 8 triple junction solar cells, 8 SOG Fresnel lenses, effective dual-axis tracking, and a forced cooling system. Analyses were performed by changing the flow rate of the working fluid at a considered solar irradiation and ambient temperature. The thermal and electrical power outputs also varied with changes in the ambient temperature and available solar radiation. The relatively high value of CPV/T power was observed against the optimum flow rate at a given irradiation and ambient temperature. Analysis of the energy of the U- shaped solar energy collector system was evaluated experimentally. The numerical results and experimental measurements of the U-shaped solar energy collector model showed great harmony, with minimal deviations of <7% between them. (C) 2014 Elsevier Ltd. All rights reserved.