Performance Evaluation and Optimal Sizing of Solar Water Pumping System Compared to Convention Diesel of Remote Site in Egypt
Authors: Ibrahim Marwa M. 
Published: September 2020

Abstract
The lack of electricity; high diesel prices affect Community water supply and irrigation pumping requirements and recent environmental issues coupled with diesel engines demand for a feasible alternative power source for irrigation water pumping. Solar power for water pumping is a good option and attractive choice for conventional diesel-based pumping systems. These systems have been introduced for various applications in many remote areas, ranging from grid extension and community water management to irrigation for agriculture and water supplies for livestock. The aim of this study is to evaluate technical, economic and environmental analysis of solar water pumping systems performance and compare them with convention diesel pumping systems to meet water requirements in irrigation, livestock watering, and neighborhood water supply fields. Recognition system design and selecting suitable design parameters is essential in order to achieve consistent and economical performance of any system. In order to design a solar water pumping system, it is necessary to collect information about the system components and local location climate data. Here , the maximum pumping power required of the solar PV water pumping system, which was determined for 121 m3/hr supply is 443 kW peak (8477 kWh/day) of inhabits residential, live stock and crops irrigation of agriculture remote site without grid power located in El Gharaq, Etsa Region, Fayoum City, Egypt. In parallel, a battery bank has been used as a backup during days of autonomy to increase the system stability. The system design investigates: diesel system, off-grid PV/battery system and compares with PV/Grid system extension power grid. The system model approach defines optimum system configurations with minimal cost of the photovoltaic modules, optimum battery bank size, and volume of storage tank. The optimization model takes into account the average monthly solar radiation, the fulfilling of the water required and the amount of autonomous days needed. The proposed sizing methodology is then performed to check the reliability of this proposed optimization method using commercial optimization software of HOMER 3.13.8, with the key parameters of minimum NPC and COE that shows better results using the system method proposed. It also estimates the pumping power capacity using calculations and equations. The results illustrated that the optimal configurations of this proposed system are 2.57 kW of PV and 2.11 kW converter of on-grid system while 3.83 kW PV and 1.71 kW converter and 10 units of 12 V batteries for PV/battery off-grid system and 3.10 kW PV for diesel system. Also, it was found that the net present cost of solar water pumping system for on-grid mode is equal 3 times of the PV-battery off-grid system and 4 times of convention diesel system net present costs. The cost of energy of solar water pumping system is 0.07 $/kWh for on-grid system while 0.332 $/kWh for PV-battery off-grid system and 0.434 $/kWh for diesel system. With a unit of 0.05 cent/m3, the system with the specified design pumps an average hourly water volume of about 121.4 m3 over one year. The return on investment is found to be 4–6 years for solar water pumping systems. Moreover, from an environmental point of view, the results showed that CO2 output for the on-grid solar water pumping system during the project's lifetime is 6 times lower than that for the standard diesel system. Through sensitivity analysis; energy costs increase by increasing the water storage tank's maximum capacity. Also, when discount rate is increasing; the NPC and COE are also increasing. The Pumping Power capacity is also estimated for this water pumping system and it is found around 10 HP. The results indicate that extension PV on-grid pumping system is the optimum solution for the selected site. Latest Egyptian Photovoltaic Pumping Incentives and policy proposals to encourage solar water pumping in developing countries are also mentioned. It also defines possible areas for investigative follow-up.