Building your own Sun Tracking Solar Panel using an Arduino

This sun tracking solar panel project uses an Arduino Uno to automatically orient a photovoltaic panel toward the brightest light source, maximizing its energy harvesting efficiency. The core sensing mechanism relies on two Light Dependent Resistors (LDRs) mounted on either side of the solar panel. Because LDRs change their electrical resistance based on light intensity, each sensor forms a voltage divider circuit with a 10k resistor. When light falls unevenly on the two sensors—meaning the sun has shifted—a difference in voltage is created between them. The Arduino Uno reads these analog voltage levels through its analog input pins. A custom control algorithm compares the values from both LDRs and determines which direction the panel needs to rotate to equalize the light on both sensors. Once the discrepancy is calculated, the Arduino generates a Pulse Width Modulation (PWM) signal to command an attached servo motor. The servo physically adjusts the angle of the MDF board holding the solar panel, turning it toward the optimal light vector. This closed-loop feedback loop runs continuously, allowing the system to track the sun's movement across the sky throughout the day.