Techo J.Trairat P.Techo J.Techo S.Pinthong T.Palamanit A.Mahidol University2025-01-232025-01-232025-01-01Engineering Access Vol.11 No.1 (2025) , 134-140https://repository.li.mahidol.ac.th/handle/20.500.14594/102753Thailand's agricultural sector, with its substantial farming population, relies heavily on irrigation from small canals to sustain the cultivation of crops such as rice, corn, cassava, and sugarcane, which are replanted at various intervals throughout the year. This study evaluates the efficiency and economic viability of a direct-coupled solar water pumping system without storage, utilizing three distinct types of DC pumps—centrifugal, reciprocating, and submersible—each with a power rating of 750 W. The field tests were conducted concurrently under controlled conditions in a specific rural area in Thailand, with each pump connected to 3×340 W photovoltaic (PV) panels. The performance analysis revealed that the centrifugal pump achieved the highest efficiency, followed by the reciprocating pump, with the submersible pump ranking last. However, despite its lower efficiency, the submersible pump demonstrated the shortest payback period of 1.7 years, compared to 2.2 years for the centrifugal pump and 3.0 years for the reciprocating pump. These findings highlight the importance of selecting the appropriate pump type based on specific irrigation requirements and system design, as each pump offers unique advantages for different solar water pumping applications and areas.EngineeringArticleSCOPUS10.14456/mijet.2025.122-s2.0-8521331728427304175