Characteristic analysis of patterned photovoltaic modules for building integration

Abstract

PV modules with customizable appearances have become attractive due to the falling cost of PV cells and the increasing demand for BIPV projects, whereas the impact of patterns on module performance has not been studied in terms of mechanism. This paper introduced a circuit simulation method for PV modules with various pattern styles, and its robustness was validated extensively through custom PV mini-module that allow for I-V curve measurements and analysis. The electrical and thermal characteristics of dot-matrix patterned (DMP) module, including short-circuit current, fill factor, peak power, energy efficiency and temperature distribution, were analyzed in detail. The results demonstrated that pattern shading decreased the module power but slightly increased the fill factor and relative efficiency, in addition to which, the power reduction of dot-matrix patterned module was less than that of continuous patterned module. When the cells of DMP module correspond to different pattern shading, the current and power of module were limited by the most shaded cell, with the lowest percentage values of 53% and 49% in this paper. Inhomogeneous pattern distribution caused additional power loss (e.g., measured 7.74% in our work) and local temperature rise for modules with same shading area. To reduce losses, the principle of using the smallest possible dot size and configuring the dot-matrix evenly was suggested to designers.