Shading effect on the performance of a photovoltaic panel

Photovoltaic modules are very sensitive to the reduction of solar irradiation due to shading. Shading can be caused by a fixed obstacle (wall, tree or even a simple pillar) or in case of circumstantial events (cloudy sky or covered with heavy smoke or dust). In order to illustrate the influence of shading on the behaviour of a photovoltaic device, a study using MatLab Simulink was carried out on a polycrystalline silicon module YL250P29. The degradation of the incident solar irradiation on a single cell of the photovoltaic panel leads to a considerable decrease in the power produced by the system (about 1/3 in the case of a fully shaded cell). We have monitored the behaviour of the bypass diode, and the pivotal role it plays in preserving the series of cells adjacent to the affected one and ensuring a reasonable rate of output.