Reflector-Augmented Photovoltaic Power Output Incorporating Temperature-Dependent Photovoltaic Efficiency

Abstract

Abstract The power output produced by Photovoltaic (PV) panels depends on the quantity of solar energy incident on the PV surface, the surface area of the module and the efficiency of the system which is a function of the module’s surface temperature. Concentration of solar irradiation onto a PV surface augments the solar energy flux on the module surface as has been shown by published literature. However, concentrated solar irradiation increases the PV surface temperature, decreasing the efficiency of the module. The papers presented in the literature review do not exam the impact of PV models temperature on performance of PV efficiency. In this work, the influence of temperature-dependent module efficiency on the power extracted from a Reflector-Augmented Photovoltaic (PV) module is explored. A reflector-collector system is considered theoretically having a variable angle between the reflector and collector as well as a variable angle between the reflector and the horizontal axis. The hourly solar radiation incident on the PV module and the reflector are obtained using TMY3 data of Dayton. The total solar radiation (direct and reflected components) striking the collector is calculated on an hourly basis which is in turn used to determine the temperature of the PV module. The electrical power produced on an hourly basis is then calculated in Dayton, OH. In order to determine the influence of temperature-dependent PV efficiency on system behavior, this study determines the electrical power produced by the system for two separate cases: a constant PV efficiency (which does not vary with temperature) as well as a temperature-dependent PV efficiency. For both cases, four separate conditions are evaluated, being different combinations of reflector-collector angle as well as reflector-horizontal angle. Results indicate that the output power of a PV module with temperature-dependent efficiency is less than the output power of the same PV module having a constant efficiency. Monthly average power increase fractions variation of both cases follows a similar trend while power increase fractions are higher during summer times than winter times. Temperature-independent power increase fractions are also higher on average than temperature-dependent power increase fractions for all four conditions.