Design of a prototypical dual-axis tracker solar panel controlled by geared dc servomotors

The main challenges of solar tracking systems are sunlight sensing for maximum illumination, providing an initial position and delays of PV panel, and designing an adequate control unit for low-consumption servomotors. The objective of this paper is to design and implement an automatic control for directing maximum solar illumination to a photovoltaic (PV) panel. The proposed dual-axis solar tracker panel prototype is used to optimize the conversion of solar energy into electricity by orienting the panel toward the real position of the sun, at a cost of mechanical complexity and maintenance need, for the best efficiency. In hardware development, two geared dc servomotors are adjusted by Pulse Width Modulation (PWM) which is controlled by a drive unit moving the panel using four Light-Dependent Resistors (LDR) to provide analog signals; these signals are processed by a simple and low-energy ATMEGA328P microcontroller with Arduino. For the software part, after data processing, a C++ programming controls two dc servomotors to position light sensors in the most favorable direction, where solar panel and sensors can be perpendicular to the sunlight.