Comparative performance assessment and model validation of the linear Fresnel concentrator (LFC) and the conical solar reflector (CSR) systems were performed under identical operating and climatic conditions. This paper analyzes the amount of heat loss by convective heat transfer (natural or forced) from the receiver to ambient air with and without a glass-reinforced plastic sheet enclosure around the collector assembly. The matlab ordinary differential equation (ode) solvers were used for simulation of the transient states. Mathematical models were generated from energy balance equations of the glass cover, absorber pipe, heat transfer fluid, and storage tank for each system. Thermal and optical analyses of the LFC (with and without an enclosure) and CSR systems were carried out by using the measured and calculated results. Satisfactory agreement was found between the experimental data and predicted results. The given models are suitable to simulate the dynamic energy flow across the different components of the LFC and CSR systems.