Optimal design and techno-economic feasibility of PV systems integrated with residential EV charging for Omani households

Integrated photovoltaic (PV) systems with residential electric vehicle (EV) charging stations are essential for advancing EV adoption, reducing carbon emissions, and promoting sustainability in the building and transportation sectors. However, their widespread adoption hinges on their techno-economic feasibility. This research investigates the optimal design and techno-economic feasibility of on-grid PV systems integrated with EV charging stations for Omani households, considering local electricity tariffs for purchasing and selling power to the utility grid. A simulation-optimization approach, utilizing HOMER Grid software, is applied to optimize the system configuration and EV charging schedule, minimizing the Net Present Cost (NPC) while adhering to system constraints. A baseline scenario, based on a household load of 54 MWh/year and Oman's current Inclining Block Rate (IBR) and Bulk Supply (BS) tariffs, reveals that reliance on the utility grid is the most cost-effective solution, with an NPC of $27.5k and annual CO2 emissions of 26.4 tons. A factorial design experiment evaluated the effects of IBR and BS tariffs, capital cost, and load profile on PV sizing and economics. Results show that under current tariff structures, reliance on the utility grid remains most cost-effective. However, factorial analysis revealed that increases in IBR and BS tariffs (simulating future tariff reforms) significantly increase the optimal PV system size and reduce the NPC, particularly when combined with reduced capital costs. These findings underscore the dominant role of tariff policy and capital cost in determining feasibility, with load profile having a relatively minor effect. They also highlight the conditions under which PV systems integrated with EV charging stations could become viable for Omani households, providing quantitative evidence to inform tariff reforms and capital cost subsidies aligned with Oman Vision 2040.