Solar Charging Station for Light Electric Vehicles

Abstract

The growth in technology and increased public interest has brought about a rapid evolution in the realm of e-mobiilty. While generally viewed as non-polluting and environmentally friendly, the Electrical Vehicles (EVs) could still contribute significantly towards indirect emissions, depending on the source of their energy. The only way they can be made truly emission free is if they are charged from renewable energy sources. This thesis aims at designing such a charging station powered by solar energy. The charging station would cater to the most popular type of Light Electric Vehicles (LEVs) - the e-bikes, and would be located at Delft in the Netherlands. Given that the Netherlands is estimated to have close to a million e-bikes already in use, the design of such a charging station would undoubtedly heighten the positive impact of LEVs. Firstly, the amount of solar energy that can be harnessed in the Netherlands is accurately found out. A photovoltaic (PV) model is developed to predict the PV module yields based on minimal weather parameters. The PV model gives a Module Ideality Factor that is indicative of the drop in PV yield due to temperature and irradiance effects. Two main system topologies are analyzed - an autonomous charging station and a grid-connected charging station - under two different load profiles. While the system reliability is of primary concern in an autonomous charging station, the electrical autarky and the Effective Autarky Ratio are optimized for sizing the grid-connected system. Lifetime estimation models are developed to predict the PV module and battery lifetimes. A basic economical analysis is performed to determine the financial viability of such a project. At large scales (several kW), the system is shown to have a Levelized Cost of Electricity (LCOE) that is grid competitive. Finally, the environmental impact of the system is studied. It is concluded that the implementation of such a charging station is not only technically feasible, but is also environmentally friendly and economically viable, especially at large scales.