Comparative Study of the Effect of Shading Rate on the Electrical Parameters of CIGS and CdTe/CdS Solar Modules

Abstract

In this paper , a comparative study of the maximum power on the shading rate on the maximum power of thin film PV modules. Thus two thin film PV modules of type Copper indium gallium selenide, CIGS, of 90W power and a CdTe (Cadmium telluride)/CdS (Cadmium sulfide) module, of maximum power 75 W. These modules, reference SN-CIGS90 and CX3 75 were tested under the conditions of the installation site to ensure their proper functioning and to determine the initial values of electrical parameters before shading. The results obtained are as follows: for the CIGS: Pm (80.717 W); Vco (23.06 V), Icc (3.5 A) and for the CdTe:Pm (54.914 W); Vco (35.52 V), Icc (1.546 A) . After this characterization test, the modules are exposed to real operating conditions at the Center for Study and Research on the renewable energy (CERER), Cheikh Anta Diop University in Dakar. Four types of shading are performed on each module with the same mask: partial shading at 25%, 50%, 75% and complete shading at 100%. The comparison of the variation rates obtained on the experimental values of the 4 types of shading carried out on each module, shows that, the phenomenon of shading constitutes an environmental factor which influences negatively the maximum power of the thin film PV modules. But this reduction depends on the surface of the shaded module, the nature of the mask but also the technology used. Indeed, for a shading of 25% of the surface of the two modules, we note a reduction of 21.32% of power for the CIGS, against 40.53% for the CdTe/CdS, that is to say a difference which approaches 20%.