Sunflower Inspired Solar Tracking Strategy: A Sensorless Approach for Maximizing Photovoltaic Panel Energy Generation

Solar tracking systems typically uses sun pointing sensors to accurately determine the sun's position and maintain the PV panel perpendicular to the direct beam of the solar radiation to maximize energy generation. However, sun pointing sensors are ineffectual without the presence of the sun and in the strong occurrence of reflected light; and are susceptible to tracking errors due to improper installation and effects of varying weather conditions. This in turn leads to poor tracking performance which adversely affects the energy generation of PV panels. To address this weakness, a sunflower inspired solar tracking strategy that mimics the heliotropic behavior of sunflowers was developed. The scheme utilizes the light-generated current from the PV panel working in conjunction with the Real Time Clock module to infer the apparent location of the sun as it traverses the sky during daytime. The performance of the single axis sensorless prototype was assessed in terms of tracking error and energy gained. The result of the experiment conducted shows that the proposed strategy achieved an average tracking error of 0.727° under different weather conditions, while sustaining an estimated average percent power loss of 0.287%. This maximizes the available solar energy received by the PV panel by 99.7%. Thus, the sunflower inspired solar tracking strategy is able to maximize energy generation. As a result, an estimated energy gain of 20.5% over an optimally tilted fixed panel was achieved.