Etude et amélioration des systèmes de conversion photovoltaïque dans les zones arides et semi-arides

Abstract

The work presented in this thesis provides an experimental study of the two most important environmental factors affecting on the performance of photovoltaic systems in arid and desert regions, which are dust accumulation and high ambient temperatures. In this regard, a series of experiments were carried out in order to evaluate the effect of these two factors under the outdoor climatic conditions of Ouargla region in the south of Algeria. In the first part of experiments, the effect of solar irradiation intensity, accumulation of dust and sandstorms were studied. The obtained experimental results showed that dust deposition on the surface of photovoltaic panels leads to a significant deterioration of their efficiency, this deterioration increases with the increasing of the accumulated dust amount. Due to the dust accumulation, the performance of a PV module decreased by 19% during the exposure period of autumn season. While, the performance of a PV power plant (30 MW) decreased by 32% after a sandstorm day. In the second part of the experiments, we proposed a passive cooling system, which is based on water evaporation and the capillary action of burlap cloth that was attached directly to the back surface of the PV module. The obtained experimental results showed the high effectiveness of the proposed cooling system in the reduction of the PV panel temperature by 26% and improve its efficiency by 14.75%. In addition, the proposed cooling system is characterised by its lower cost and lower water consumption compared to all previous cooling technologies. Moreover, it is environmentally friendly and without side effects. This makes it a promising solution for the overheating problem of photovoltaic panels in arid and hot regions