Annual energy losses due to partial shading in PV modules with cut wafer-based Si solar cells

• Published in: Renewable energy 2021-05, Vol.168, p.195-203
• Main Authors: Brecl, Kristijan, Bokalič, Matevž, Topič, Marko
• Format: Article
• Language: English
• Subjects: Cut cells; Energy balance model; Losses; PV module; Shading
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2020.12.059

To further improve the efficiency of the wafer-based silicon photovoltaic (PV) module, producers are introducing new module designs with cut-cells. Since smaller solar cells might be affected by partial shading even more and earlier than full-size cells, the energy performance simulations of partially shaded modules are crucial. A detailed shading analyses of partially shaded modules with different cut cell designs are presented not only on a single case scenario but on annual energy yield simulations using Spice, where a shading scenario over the whole module by the use of a new 3D shading horizon profile of selected shading objects is calculated. The annual simulations reveal that regardless the module design almost all cells in the module are confronted by reverse bias, which can deteriorate the module performance significantly. Simulation results with three different shading objects on five different module topologies at five locations showed that the best cut-cell module design depends strongly by the micro location and shading objects; however, in general the string of solar cells connected in series should be aligned with the shading shape around noontime as much as possible. A comprehensive annual energy performance evaluation of partially shaded cut-cell modules revealed; that with a correct cell layout of cut-cells in a PV module, the shading losses can be reduced by 30–50% if comparing to the standard PV module design. •Annual energy performance model of partially shaded modules.•Energy balance model for partially shaded modules.•Comprehensive electrical evaluation of the partially shaded module on the cell level.