Super-Capacitors as an Alternative for Renewable Energy Unstable Supply

Abstract

In this article a Lithium battery and super-capacitors performance for energy storage in renewable is compared. A photo-voltaic system is considered with Lithium-ion (Li-ion) battery, then with a super-capacitor compared as the storage device. The super-capacitor consists of 10 capacitors connected in series and one in parallel. The comparison is made based on the state of charge and the output voltage of the two storage devices. Matlab/Simulink model is developed to make the analysis of the two systems. Li-ion battery displayed a uniform voltage of 0.9 V while the super-capacitor accumulated 250 V; when the simulation was done within a specific time frame. The Hybrid system however, drew a lower voltage of 15 V but a more stable supply is achieved over time. While the state of charge of the battery is constant over the time of simulation, the super-capacitor increases with time. The details of the simulation are presented in the full paper.