Design and Performance Evaluation of an Automatic Solar Tracking System Using LDR Sensors and NodeMCU

Solar energy is one of the most abundant and environmentally friendly renewable energy sources available today. However, the efficiency of conventional fixed solar panels is significantly limited due to the continuously changing position of the sun throughout the day. This paper presents the design and implementation of an automatic single-axis solar tracking system that dynamically orients a photovoltaic (PV) panel perpendicular to the sun's rays in order to maximize energy harvesting. The system employs two Light Dependent Resistor (LDR) sensors to detect differential light intensity, a NodeMcu (ESP8266-based) microcontroller for processing and decision-making, an L293D motor driver IC, and a 10 RPM DC motor for mechanical actuation. Experimental results gathered over multiple days in April 2019 confirm that the tracking system consistently outperforms a fixed-panel arrangement, achieving higher PV output voltages across all daylight hours. The proposed system is low-cost, easy to implement, and suitable for small-scale renewable energy applications.