Performance improvement of solar module system using flat plate reflectors

Photovoltaic (PV) modules based on silicon solar cells are widely used to convert solar energy into electrical energy. The energy output of these modules is very low due to their low power conversion efficiencies of approximately 15%. Reflectors are used to improve the power output of PV modules, by increasing the effective capture area. The performance of the solar panel with reflector depends mainly on three parameters namely length, tilt angle and reflectivity of reflector. Hence it is necessary to choose the optimum values of these parameters to attain maximum power output from the system. We have developed a model system to analyse the effect of reflector parameters on the overall power output. This has an arrangement for varying the tilt angle of the reflector. Also a simplified mathematical model was developed which is capable of estimating the optimum tilt angle for a particular reflector length, and the optimality of the tilt angles predicted by this model was verified using the above mentioned experimental setup. Finally, the suitability of various materials for use as reflectors was studied using the setup. Interestingly, paper based reflectors like bond paper and thermocole showed excellent results with increase in power output of more than 60%. Also, the cost per watt of the system is minimal when we use aluminium foil as the reflector at optimum tilt angle.