Optimal Sizing of PV Water Pumping System for Off-grid Rural Communities

A large population worldwide lives in remote rural communities without access to electricity due to the limited reach of national transmission networks. This creates significant challenges in accessing water, hindering improvements in living conditions for off-grid communities. Photovoltaic water pumping systems (PVWPSs) offer a viable solution to this issue, but their sustainability must be examined due to the unpredictable nature of solar radiation. This paper presents a practical techno-economic approach to optimally size a PVWPS. A Particle Swarm Optimization (PSO) algorithm is employed, considering technical and economic indicators like life cycle cost, loss of load probability and PV curtailment rate. The system’s optimal sizing considers the installed photovoltaic power capacity and water storage tank volume to meet the water needs of a rural village in Egypt's Western Desert. The findings confirm that the optimal configuration includes nine PV modules in series and four strings in parallel, and a 71 m³ storage tank. Sensitivity analysis in terms of deficient days and curtailed PV power is conducted for two scenarios with and without using a storage tank. As a result, the annual LLP drops from 0.38 in the scenario without a tank to 0.005, with a slight increase in the LCC. The optimal capacity configuration results are considered feasible and satisfactory, especially in developing nations like Egypt, which face infrastructure challenges and high solar radiation. This study is of immediate relevance and potential importance to environmentally sustainable and cost-effective water supply systems studies in off-grid rural areas.