Performance Evaluation of Solar Water Pumping System for Small-Scale Irrigation in Ethiopia

Ethiopia’s agriculture, which is mainly rainfed and managed by smallholder farmers, faces significant productivity challenges due to limited rainfall during a short rainy season. Solar-powered water pumping offers a sustainable and efficient alternative for dry-season irrigation by harnessing the country's abundant solar energy potential. This study presents a novel approach to optimizing solar-assisted water pumping systems by evaluating the hydraulic and electrical performance of both centrifugal and helical rotor pumps under varying flow rates and solar irradiance levels. The findings indicate that system efficiency peaks at specific heads depending on solar irradiance: at 450 W/m², a head of 16 meters achieves 33% efficiency; at 750 W/m², a head of 20 meters yields 34%; and at 950 W/m², a head of 28 meters achieves 32% efficiency with a centrifugal pump. Notably, the helical rotor pump demonstrates superior performance for applications requiring consistent pressure at low to moderate flow rates. This study provides valuable insights into the head-flow relationship, optimal operational conditions for various solar irradiance levels, and comparative performance metrics of different pump types, offering practical guidelines for enhancing the efficiency of solar-powered irrigation systems.