Sun tracking mechanism effects on flat plate photovoltaic system performances for different step time and main parameters affecting the obtained gains: case of North Africa and Mediterranean site.

摘要

This work is performed to investigate the effect of using different types of sun tracking mechanisms on the flat plate photovoltaic system performances and the main parameters affecting the amount of their output electrical energy as well as those affecting their gains compared to the traditional fixed photovoltaic systems. The evaluation of different systems has been performed on the basis of hourly measured data over a complete one year obtained from Bouzareah location (Mediterranean coastal site). Considering all sky states, the monthly and yearly produced electrical energy by each one of the considered systems as well as the electrical gain of the photovoltaic panel mounted on different sun tracker systems were evaluated. From these latter, it appears that the highest gains obtained are those related to the two axes sun tracker system, which decrease gradually, from the inclined to the vertical rotating axis if the same optimum slope scheme is considered and from seasonal to the yearly optimum slope if the same rotating axis scheme is considered. So, from the obtained results, appears that if also, all sky states conditions were considered, compared to the single axis sun tracking systems, the gain obtained by the two-axis sun tracking system is relatively low and don't exceed three percent for some cases. On the other hand, is also observed that the quantity of electrical energy produced by the different systems follows a seasonal variation and mainly related to the sun tracker mechanism under consideration, the choice of the panel slope, the availability amount of solar irradiation amount mainly the normal direct component, the day length and from the seasonal variation of the weather conditions.