Development and Implementation of a Low-cost Automatic Dual-axis Solar Tracker through Hardware/Software Embedded Program Control

Abstract

A solar tracker is a system that is used for the mechanical orientation of solar payloads (collectors and photovoltaic panels) towards the sun. A simple, low-cost, but effective open-loop dual axis solar tracking system was developed in this work. The tracker is an embedded system that consists of a microcontroller integrated with other components in an electronic circuit to coordinate the activities of the circuit in driving out and in the motor shafts of electrically powered linear actuators used to move the payload. The work is divided into two parts: hardware and software. The hardware part consists of two movable (tilting and axial moving) rectangular frames fixed together and used to hold the payload and two electrically powered linear actuators (jacks) used to move the rectangular frames in the tilting and axial directions. The software part was a code written in the C programming language following an algorithm developed from measured parameters of the jacks and the sun’s position and embedded into a microcontroller. The testing of the dual-axis solar tracker was done by measuring a parabolic trough collector’s position with respect to the sun hour angles and solar declination angles and comparing the values with the calculated angles for two days. The results obtained showed that the tracker followed the sun with deviation of ±2o (percentage errors that ranged between 0.01% and 3.26%).