A bypass diode is a Schottky diode wired across a group of series-connected solar cells that provides an alternate current path when cells are shaded or damaged. Every standard solar panel has 3 bypass diodes, each protecting roughly 20 cells. Most of its power systems are installed on rooftops, integrated into buildings. When shade hits even one cell, the bypass diode for. This paper presents a comprehensive review and highlights recent advances, ongoing research, and prospects, as reported in the literature, on bypass diode application on photovoltaic modules. First, it outlines the shading effect and hotspot problem on PV modules.