IoT-Enabled Hybrid Solar-Wind EV Charging System with Battery Storage and Automatic Source Switching

Abstract

The use of Electric Vehicles (EVs) is increasing day by day, and this creates a need for a reliable and eco-friendly charging system. Most of the existing EV charging systems depend on grid electricity, which can be costly and not environmentally friendly. To overcome this problem, this project presents the design and implementation of an off-board hybrid EV charging system using solar, wind, and grid energy sources. The system is designed to provide continuous charging by automatically selecting the available energy source based on voltage level. In this project, a solar panel and a wind energy source (DC motor) are used as primary renewable energy sources. When either of these sources produces sufficient voltage, it is used for charging. If both sources are not available, the system switches to grid supply as a backup. A battery charge controller is used to ensure safe charging of Li-ion batteries, and a DC-DC boost converter is used to maintain stable output voltage. The system is controlled by an Arduino Nano, which manages source selection and relay switching. An ESP8266 NodeMCU module is used for IoT-based monitoring, allowing real-time data display through a web interface.On the vehicle side, a battery monitoring system is used to measure voltage and current for safe operation. It also provides automatic switching between main and backup battery to ensure continuous power supply to the load. The hardware model of the system was successfully developed and tested under different conditions. The results show that the system can provide continuous, efficient, and reliable EV charging. The integration of renewable energy sources reduces dependence on grid power and supports clean energy usage. Overall, the project demonstrates a simple, cost-effective, and sustainable solution for future electric vehicle charging systems.

Introduction

This project proposes a hybrid Electric Vehicle (EV) charging system that combines solar, wind, and grid energy sources with battery storage to provide reliable, efficient, and eco-friendly charging. Traditional EV charging mainly depends on grid electricity, which can be expensive and unreliable due to power outages and voltage fluctuations. To address these issues, the system prioritizes renewable energy sources, using solar power as the primary source, wind power as a supplementary source, and grid power as a backup when renewable energy is insufficient.

The system automatically selects the most suitable energy source based on voltage availability and uses SEPIC and bidirectional DC-DC converters to maintain stable voltage and manage energy flow. A Li-ion battery bank stores excess energy and supplies power during low-generation periods. An Arduino Nano controls automatic source switching through relays, while an ESP8266 NodeMCU enables IoT-based real-time monitoring of voltage, current, and charging status through a web interface.

The literature review highlights that most existing studies focus on individual aspects such as solar integration or converter design, with limited emphasis on complete hardware-based hybrid systems. This project addresses these gaps by integrating multiple energy sources, automatic source selection, battery backup, and real-time monitoring into a practical and low-cost solution.

The methodology includes studying renewable energy generation, battery charging, converters, and control systems; designing a block diagram; selecting components; integrating solar, wind, battery, and grid sources; implementing automatic switching and voltage regulation; and developing an IoT-based monitoring platform. Overall, the project aims to improve charging reliability, reduce electricity costs, promote renewable energy use, and support sustainable transportation.

Conclusion

The project titled “Design and Performance Evaluation of an Off-Board Hybrid Solar PV Based Electric Vehicle Charging System” has been successfully designed and implemented. The system uses a combination of solar, wind, and grid energy sources to provide continuous and reliable charging for electric vehicles. The hardware model was developed using components like Arduino Nano, relays, boost converter, battery charge controller, and Li-ion battery. The system was tested under different conditions, and it was observed that the automatic switching between energy sources worked properly based on voltage availability. The use of renewable energy sources helped in reducing dependence on grid electricity and made the system eco-friendlier and more cost-effective. The battery was charged safely and efficiently with proper control of voltage and current. In addition to hardware implementation, an IoT-based monitoring system was also developed using ESP8266, HTML, and PHP. This allowed real-time monitoring of system parameters such as voltage, current, and charging status through a web interface. The login system ensured secure access, and the separation of charger phase and vehicle phase made the interface user-friendly. Although the system is implemented on a small scale, it clearly demonstrates the concept of a smart hybrid EV charging system. With further improvements and scaling, this system can be used for practical applications in EV charging stations. Overall, the project proves that combining renewable energy with smart control and monitoring can provide an efficient, reliable, and sustainable solution for future electric vehicle charging needs.

References

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Copyright

Copyright © 2026 Aiswaryamol M, Saranya Nair. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.