This paper describes how the unique optics of Spheral Solar(TM) Cells have been modelled by ray-tracing techniques. A Monte Carlo statistical code (Win Trace) has been developed in order to perform routine calculations over a large number of random events. Laser scanning and photometrical techniques have been employed to validate the simulation results, A good agreement between simulated and measured data has been found. The simulation reliability is fundamental for the future use of the code to design an optimised structured cover, focusing light onto active cell areas.