This work aims to investigate the performance of a new design for CPV/T system using 3D flat sided (3D V-trough) concentrators named squared (SAC), Hexagonal (HAC), Octagonal (OAC) and Circular (CAC) inlet and exit Aperture concentrators, with an effective cooling facility that keeps PV temperature within the Normal operating range. Novel mathematical optical models were generated, to the HAC and OAC geometries and validated using OPTISORKS software, to calculate the geometrical concentration ratio (GCR) and actual concentration ratio (ACR) by the inlet aperture area (A_in) a function of aperture width (W_in) and number of reflections (n), and material reflectivity (p) and at any concentrator side angle (Ψ), consequently the optical performance. Results showed that the optimum concentrator side angels for GCR of 2, 4, 6, 8 and 10 are 35°, 30°, 20°, 20° and 15°, respectively for all investigated geometries. Also COMSOL Multiphysics software was used for thermal modelling. Optical, thermal and electrical investigation results highlight that the designed CPV/T system is beneficial enough and feasible to be used in generating electrical and thermal powers for domestic use, as one useful package of energy with high output compared with the flat PV modules which generate only electrical power.