Verification of computational optimum tilt angles of a photovoltaic module using an experimental photovoltaic system

Abstract

Determination of the optimum tilt angles of a photovoltaic module is of great importance because the power of photovoltaic module is highly dependent on the incident solar radiation. The purpose of this research was to verify the computational optimum tilt angles of a PV module by conducting an experimental research in Kerman‐Iran. For achieving this, first, the optimum tilt angles were found using a computational model which predicts the module output energy at different tilt angles. Second, monthly, seasonal, biannual, and annual optimum tilt angles of a photovoltaic module were measured. The experimental optimum tilt angles were obtained based on 1 year measured data of the output energies of photovoltaic modules. The experiments were carried out by measuring the output electrical power of six photovoltaic modules which were inclined toward the south at different tilt angles throughout the year. The experimental optimum tilt angles were then determined based on the maximum output energy of the PV modules. Finally, the computational optimum tilt angle and the experimental optimum tilt angle were compared with each other. The results showed differences between the calculated and the measured optimum tilt angles of a PV module in the region under investigation. It was revealed that the measured annual optimum tilt angle is higher than the calculated annual optimum tilt angle. This difference was due to lack of the environmental parameter influences such as dust deposition on the PV front surface in the computational model. This study clearly showed that fixing the photovoltaic module based on the calculated annual optimum tilt angles decreases 3% the electrical output energy of photovoltaic module throughout the year compared with that fixed at the experimental optimum tilt angle. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 1156–1165, 2015