Full spectrum optimized transmissive solar cells have multiple p-n junctions made from different semiconductor materials. Each material’s p-n junction produces electric current in response to a different wavelength of light, which means the cell allows absorbtance of a broader range of wavelengths and improves the cell’s conversion efficiency. Light(infrared) transmitted through the cells is then received by a thermal receiver/heat exchanger to heat the water/oil inside a serpentine patterned channel with dimples to decrease the pressure drop and increase heat exchange rate. The photovoltaic PV module designed at Tulane University, a partner on our project, has a 7 X 7 square array of fullspectrum optimized transmissive PV cells made by SPECTROLAB and thermal receiver designed and fabricated by USD. In this thesis, a high Flux solar simulator (HFSS) using single 15kWe xenon short-arc lamp with a truncated ellipsoidal reflector was optically characterized at San Diego State University. This facility makes it possible to form a uniform high radiation flux density distribution over a spatially adjustable platform moving in and out of focus reaching stagnant temperatures, allowing analysis of prototypes under concentrated solar energy conditions. A novel, diffusely transmitting target method was developed to make flux density distribution maps with help of image processing in MATLAB for simulator and on-sun (parabolic dish) testing. Results from Lambertian target and diffusely transmitting target have been compared. The goal of the current project has been to assemble and initially test the designed Concentrated Photovoltaic/thermal system under high fluxes, results up-to 200 suns concentration have been presented. Temperature profiles and electrical output are used to measure the efficiency of the CPV and Thermal Receiver. A tank-in-tank design, thermal energy storage system, insulated by vacuum and copper shields carrying 10Ltr. of solar salt at 560°C has been tested for 6 hours round trip efficiency.