In this paper, simulation of a linear Fresnel rooftop mounted concentrating solar collector is presented. The system is modeled with the transient system (trnsys) simulation program using the typical meteorological year file containing the weather parameters of four different cities in Australia. Computational fluid dynamics (CFD) was used to determine the heat transfer mechanism in the microconcentrating (MCT) collector. Ray trace simulations using soltrace (NREL) were used to determine optical efficiency. Heat loss characteristics determined from CFD simulation were utilized in trnsys to assess the annual performance of the solar cooling system using an MCT collector. The effect of the different loads on the system performance was investigated, and from trnsys simulations, we found that the MCT collector achieves a minimum 60% energy saving for both domestic hot water usage and high temperature solar cooling and hot water applications.