Design and Implementation of A Low-Cost IoT-Based Data Logger for Solar and Wind Energy Monitoring

Abstract
As the adoption of renewable energy sources continues to grow, there is a critical need for efficient, scalable, and affordable monitoring solutions. This paper presents the design and implementation of a low-cost Internet of Things (IoT)-based data logger tailored for solar and wind energy systems. Utilizing the ESP32 microcontroller, the system integrates temperature, current, voltage, and irradiance sensors to monitor photovoltaic (PV) and wind energy performance in real time. Data is recorded locally on an SD card and simultaneously pushed to a Firebase real-time database, enabling remote access and visualization via a Node-RED dashboard. Simulation through the Wokwi platform confirmed the functionality prior to hardware deployment. The system achieved accurate measurement performance, with error margins ranging from +1.57% to +3.78%. This solution provides a reliable, scalable, and cost-effective approach for renewable energy monitoring, particularly in rural and off-grid environments. Keywords - IoT, Data Logger, ESP32, Solar Energy, Wind Energy, Renewable Energy Monitoring, Firebase, Node-RED.