Design hybrid renewable energy systems for electric vehicle charging stations at various sites in Pakistan

The number of EVs is increasing rapidly globally, and that means the need for more sustainable and economical charging. A continuous supply of clean energy is required for the Highway EV charging stations that are crucial for intercity mobility functions. One of the possible solutions is a hybrid renewable energy system technology, which has wind and solar photovoltaic (PV) energy. Most of the previous studies, though, are based on limited grid support and/or renewables penetration and system integration, limiting both sustainability and cost performance for high-demand applications. The authors suggest a solution for EV charging stations by proposing a hybrid wind-solar system grid-connected along the major motorway routes in Pakistan, namely, Bhera Motorway, Hakla Motorway, Karachi Northern Bypass, and Karakoram Highway. The novelty is the ability to achieve very near-grid-independent grid operation while still adhering to optimized renewable sizing, which helps minimize reliance on the conventional electricity grid and hence the amount of variability in the costs of grid energy. The system emphasizes the cost-optimized use of generation sizing with optimized grid interaction control whenever required and reduces battery investment, thus minimizing the system lifecycle cost. It can reduce energy costs, compared with fossil fuel transport energy (petrol and diesel), which makes it more sustainable in terms of the economy. Solar irradiance and wind speed data are solar-specific; EV load profiles are selected from the available ones in the EV automobile industry, and the grid characteristics of the exchange are run using the HOMER Grid software application to carry out the techno-economic analysis. One 250 kW wind turbine, one 400 kW solar PV array, and one 700 kW bidirectional DC–AC converter (modes: from DC to AC or from AC to DC) are built into each station, although the optimum sizing may differ depending on the location. The NPC of Bhera Motorway is around $15,929, LCOE is around $0.0225/kWh, and annual operating cost is around $11,643/yr. Combine the lowest cost configuration (Hakla Motorway ~ $7,893 with LCOE ~ $0.0214/kWh) to get the lowest cost overall. The NPC is the highest for Karachi Northern Bypass (ca. $78,214), and the highest LCOE for the four sites is at Karachi Northern Bypass (ca. $0.0286/kWh). It is found that the performance of the Karakoram Highway is similar to the Bhera site; the NPC is $15,951, and LCOE is $0.0225/kWh. Based on these conclusions, it can be seen that the deployment of a hybrid renewable system can offer affordable EV charging to achieve EV grid parity with low CAPEX and OPEX, which helps in transportation development in developing areas while being sustainable in nature.