Integration of Specular Reflector in a Dual Axis Solar Tracker

Abstract

In the Philippines, the installation of solar panels on the rooftops of residential and commercial buildings has increased in popularity. Even if the country has high solar insolation, energy conversion is still inefficient since the solar panel arrays are not always facing in perpendicular to the sun. Technologies related to increasing the solar panel efficiency such as solar trackers are usually complex and expensive. This problem is addressed by designing a low cost dual axis solar tracker with the integration of specular reflector system. The dual axis tracker system can move the panel and the reflector assembly in a precise and controlled manner to ensure maximum output. This was achieved by using a LDR (Light Dependent Resistor) compass assembly, gear system, and stepper motor mechanism. To measure the solar panel output, a voltage sensing circuit was incorporated instead of using the existing optical and time-based techniques. The system performance was tested in both the controlled and the actual environments. Experimental data have shown that when the panel is perpendicular to the light source, the system yields maximum energy. The need for a tracking and planar reflector system is notably important when the light source moves away from the normal because this results to a significant drop of the panel’s average efficiency. The addition of the tracker alone had greater enhancement effect than with the specular reflector only. The tracker boosts the efficiency by 69.55% while the specular reflector boosts it by only 15.12%. Combining the tracker and the specular reflector yields the best result with a 92.33% boost on the average efficiency.