Shading-loss enhancement of high-density photovoltaic shingled module for urban building applications

Abstract

In shingled photovoltaic (PV) modules, solar cells are separated and connected in series using electrically conductive adhesives (ECA). Shingled strings, made up of strips of cells connected in series, are designed with high voltage and low current characteristics, reducing resistance losses and enabling the production of highly efficient photovoltaic modules with lower spatial losses compared to conventional PV modules. However, this approach has the drawback of increased susceptibility to shading, as it uses smaller segmented solar cell strips in the separation process compared to the typical strings of conventional PV modules. In urban buildings, shading is common and therefore shading issues need to be addressed. The proposed string cross-connection method involved tying one or two shingled strings together and arranging them crosswise. When 25% of the bottom surface of the module was shaded, the current was bypassed by bypass diode, reducing the output to 52% for the conventional string interconnection method. However, the novel method resulted in bypassing at 41.6% shading and improved the output degradation rate by approximately 17% when the same area was shaded.