Optimizing Solar Panel Tilt Angle and Direction for Maximum Efficiency: A Comprehensive Analysis

Abstract The solar photovoltaic (PV) is considered to be the one of the most promising energy source in many applications, due to its safety and high reliability. But the initial high cost of the PV arrays and the large area necessitate their optimum use. The maximum theoretical limit (known as the Shockley-Queisser limit) for silicon p-n junction cells is 33.7% and most current commercial PV cells manage between 15 and 22%. The declination angle δ=−23.45°×cos(360/365×(d+10)) of the sun changes due to the rotation of Earth about an axis form maximum value is 23.45° on 21 December and the minimum is −23.45° on 21 June. One of the solutions that optimize the array performance is to adjust the array tilt such that the incident insolation on the array is maximized. The best results are obtained when the movement of the sun is tracked both on a daily and seasonal basis. However, as this scheme is costly and involves complex control, alternative solutions have been sought for. In the simplest way, the PV panels are inclined at the latitude angle of the site, throughout the year. Many researchers found that latitude angle is suitable angle for PV panel tilt angle. However, it is observed that a decrease in the tilt angle than latitude angle in summer and an increase in the tilt angle in winter enhances the solar energy received on the panels significantly. Optimal tilt angles and corresponding monthly solar insolation values have been compared among latitude angle, fixed tilt angle, and bi-annual changing (fixed twice a year). The changing solar panel tilt angle twice in a year gives maximum power output.