Abstract
Presented in this paper was an overview on research works on solar radiation basics and photovoltaic generation. Also, a complete PV modeling and investigation on the effect of using multi-axes sun-tracking systems on the electrical generation was carried out to evaluate its performance using the case study of the Monastir city, Tunisia. The effects of azimuth and tilt angles on the output power of a photovoltaic module were investigated. The instantaneous increments of the output power generated by a photovoltaic module mounted on a single and dual-axis tracking system relative to a traditional fixed panel were estimated. The results show that the yearly optimal tilt angle of a fixed panel faced due to the south is close to 0.9 times Monastir latitude. The gain made by the module mounted on a single-axis tracking panel relative to a traditional fixed panel was analyzed. The monthly increments of the gain are more noticeable for two critical periods which correspond to those surrounding the summer and the winter solstice dates. It reaches the value of 10.34% and 15% in the summer and winter solstice periods, respectively. However, the yearly gain relative to a fixed panel installed with the yearly optimal tilt angle is 5.76%. In some applications, covering loads at early morning or late afternoon hours and in order to more optimize the solar systems exploitation suggest the adjustment of the PV panel orientation to azimuth angles different from the south direction by using a dual-axis tracking installation. The gain made by this recommendation relative to a traditional fixed panel is evaluated. This gain reaches 30% and 44% respectively in the winter and summer solstice days. (C) 2011 Elsevier Ltd. All rights reserved.