Designing an Economically Viable Off-Grid Photovoltaic System Considering the Battery Discharge Rate

The primary significance of harnessing power from clean and renewable sources lies in the fact that numerous rural areas are far from the utility system. Among the renewable energy technologies catering to power needs in residential areas is the solar photovoltaic (PV) system. Despite the potential of PV technology and the abundant sun radiation exposure in Hurghada, Egypt, there is a lack of empirical studies evaluating the feasibility of off-grid power production using this system. A notable aspect of this study is the consideration of the discharge rate of the battery for sizing the off-grid system, involving the distribution of the load throughout the day. In Hurghada, Egypt, the study conducts a design and cost analysis of the proposed system for a load exhibiting three different patterns. The novelty of the study is that the total system cost reduction is investigated in relation to varying battery discharge rates (C-rate) or time-based load distribution and showing its effect on saving in costs. The results indicate that a more extended distribution of the load throughout the day results in increased discharge hours, reduced battery capacities, and more significant savings in annualized life cycle costs and electricity costs. Specifically, distributing the load across the day leads to approximately 23.33% savings compared to a distribution across five hours.