Standalone Solar-Wind Hybrid Energy System with the Integration of Supercapacitors

Abstract

INTRODUCTION

People located in off-the-grid areas do not have access to electricity, while most people living in areas with access to the electrical network do not have alternative source of energy during power outages. Solar panel and wind turbine were combined to form a hybrid energy system to provide power to off-the-grid households and alternative energy source to on-grid households. This system utilized the capabilities of supercapacitors to receive and store energy. A selector circuit was created to select which energy storage will supply the household.

METHODS

Prescriptive Research design was used in this study. The design process includes, the system design, hardware and software implementation and system testing. The system design process was undertaken to come up with the block diagram of the system which will serve as guide in the creation of the prototype. Hardware implementation is the creation of the schematic diagram and the actual circuit. Software implementation is the creation of the program code inputted to the microcontroller which will provide the action of the selector circuit. Testing was done to determine if the system is providing the desired output.

RESULTS

The selector circuit automatically switches from one energy storage to another depending on the voltage levels of the batteries connected to the energy sources. It selects which energy storage will provide power to the inverter. The selector prioritizes solar battery. When its voltage level is below 10.5 V, the selector selects the wind turbine battery provided its voltage is greater than 10.5 V. When the voltage of the solar panel battery is greater than 10.5 Volts the selector selects this battery again. When both voltage levels of the solar panel and wind turbine batteries are below 10.5 V, the selector selects the supercapacitor bank to supply the inverter. Actual test showed that the hybrid energy system can supply a typical off-the-grid household loads such as LED bulbs, TV and electric fan.

DISCUSSIONS

One of the challenges encountered in this study is the accurate state of charge determination when the battery is being used by the system. A circuit that will accurately monitor the state of charge (SOC) of the batteries will improve the hybrid system. Another improvement is the placement of voltage and current level indicators for the user to have a better sense of what is happening in the system.