Analysis of the performance of rooftop mounted PV panels against horizontal panels and inclined panels

Abstract

This study presents an experimental investigation of the performance of roof-top mounted photovoltaic (PV) panels compared to horizontal panels and panels inclined at the angle of the latitude. The aim is to provide technical recommendations for the optimal installation angle of PV panels, which is easy to implement in the absence of a tracking system. The materials utilized in this study include twelve 100W PV panels and twenty-four digital ammeters and voltmeters. Hourly measurements of the current and voltage from the PV panels placed in the following settings – rooftop (4), inclined (4), and horizontal (4) – were recorded over one year. Results obtained showed that the orientation of the PV panel plays a crucial role due to the rotation of the Earth. Inclined panels achieved the highest performance with superior current, voltage, and power outputs throughout the day. An 8-degree inclination angle (corresponding to the latitude) optimizes sunlight exposure while rooftop panels performed well but are affected by shading in the early morning and late afternoon, resulting in slightly lower performance compared to inclined panels. The key recommendations are that panels inclined at an 8-degree angle (matching the angle of latitude) provide the best performance, maximizing sunlight exposure and power output, and for rooftop installations, it is crucial to account for shading during sunrise and sunset, as positioning panels to minimize shading can significantly enhance overall performance.