Optimum PV module interconnection layout and mounting orientation to reduce inhomogeneous soiling losses in desert environments

Photovoltaic modules in desert areas benefit from high irradiation levels but suffer, among other parameters, from high soiling ratios, which influence the output power of the modules. Power loss due to soiling can reach more than 20% per month if not cleaned. Besides, inhomogeneous soiling by accumulation of dust on the corners and bottom of the modules may lead to total power loss of the modules. Modification in cell sizes, electrical interconnection, and mounting orientation of the modules can reduce the losses from inhomogeneous soiling. In this paper, we evaluate the performance of three module designs with full- and half-sized solar cells with different interconnection designs for different inhomogeneous soiling conditions. The modules are investigated in two mounting orientation of portrait and landscape installation with two scenarios of corner and edge soiling. The simulation results supported by the experimental data indicate that the PV modules in favorable mounting positions show up to 65% higher output power depending on the module design and soiling patterns. It is shown that our proposed optimized design mounted in favorable orientation is less sensitive to the inhomogeneous soiling and shows less current losses compared to the nominal operating current. Consequently, the module shows less current mismatch with the other modules in an array.