Design and performance analysis of electric Tuk-Tuk charging stations powered with renewable energies in South Africa

Abstract

The success of renewable powered electric vehicle charging stations in isolated areas depends highly on the availability and sustainability of renewable resources all year round at selected locations. A hybrid renewable energy system (HRES) is a viable option for isolated standalone off-grid areas. The HRES should be incorporated with an energy storage system (ESS), which will be utilised as a storage unit when the generated energy at the station exceeds the load requirements. The ESS will also serve as a backup energy supply system, when the HRES is unable to meet the load requirements. Research has indicated that the most reliable, efficient and flexible energy storage system for HRES is rechargeable batteries. However, frequent discharge cycling utilisation of battery banks imposes a penalty on the battery life span. The rate of discharging and charging the battery bank will either increase/decrease the maintenance and replacement cost. This study will have two major purposes: (1) will be to investigate the possible charging strategies that could be implemented to find the best possible configuration of an electric Tuk-Tuk charging station in the rural areas, and isolated islands of South Africa. The charging station will be designed, modelled and simulated to evaluate its performance. The techno-economic analysis of different feasible supply configurations of the charging station using renewable energies will be simulated using HOMER energy software, and the results will be compared in order to select the most viable charging strategies in terms of the cost of energy (COE) produced. (2) Will be to investigate the possibilities of controlling and optimising the daily operation of a standalone hybrid renewable energy system by maximising the usage of the renewable resources whilst minimising the utilisation of the battery bank for supplying the required energy at an electric Tuk-Tuk charging station without any load rejection. The effectiveness and efficiency of the proposed control strategy will be performed and simulated using fmincon in a MATLAB environment. The results for different scenarios will be presented and analysed for different potential sites in the rural parts of South Africa where the charging stations could be sited.