Life cycle analysis of PV-assisted charging station

Due to increasing population and technological developments, the demand for energy continues to increase in the developing countries. Strong rising trends have been also recorded in Turkey and Asian countries. In response to this demand, hydrocarbon-based fossil fuels have always had a larger share than other primary energy sources. This causes problems such as environmental pollution, high emissions and global warming. Transportation sector forms large portion of this problem. But electric vehicles can be a solution to this problem. Increasing penetration of electric vehicles into daily transportation system can bring new opportunities not only to reduce environmental emissions and grid impacts but also more profit for vehicle owners and vehicle charging station owners. This study proposes a hybrid model of optimization for scheduling of a charging station using battery storage. Electric vehicle charging station offers bi-directional energy transfer both from grid to vehicle and from vehicle to grid. Vehicle-to-Grid (V2G) technology enables the electricity stored in the batteries of electric cars to be made available to the grid at times of high demand. When demand is low vehicles can perform regular charging. With this technology EV drivers will have opportunity to earn money depending upon their contribution to grid. On the other hand, this storage capacity can be used by grid operators to balance peaks and troughs of energy demand and supply. Because of environment friendly solution for the charging process of electric vehicles is one of the most important issues, the designed station is also intended to make use of solar energy source. This model has an electric vehicle station with ten vehicle-size, an external storage battery, solar panels and grid connection. In the charging station part, the hourly power demands of the vehicles and the possible energy amounts that they could transfer to the other vehicle or network were calculated on an hourly basis. Hourly solar power production was also calculated. Then system checks the relation between EV demand, possible supply and solar power which is called operational scenarios. According to the operation scenarios, decisions such as electricity purchase from grid, storing excess energy in battery or transferring excess energy of vehicles from one to another are taken. Then objective function and the basic technical and economic constraints and parameters of the four main parts of the system were established. As a result, a model that evaluates economic benefits to calculate potential operator revenue was developed with MATLAB. Then, the states of these variables were studied according to scenarios. Two scenarios were created at this stage. In the first part of the first scenario; the system was operated with the actual price and demand and market prices in accordance with the regulations in Turkey. In the second part, the conclusions that will arise when the prices fall below the European Union prices have been examined. In the second scenario; price parameters affecting the system are calculated based on future prices. In this scenario; changes in market prices that occurred in Europe was examined and prices may occur in Turkey was added as an input to the system. The results of two key case studies were compared to examine the impact on the system of changing prices such as different electricity sales prices, parking fees and charge service fees.