Performance Assessment of a Solar Water Pumping System Under High-Head Conditions in Sumba, Indonesia

A 2.4 kWp Solar Water Pumping System (SWPS) was installed in Kadaghu Tana, South West Sumba, to provide clean water from a total head of 115 m. The site receives 4.8-6.0 kWh/m2/day of solar irradiation. The system uses Photovoltaic (PV) modules connected to a Lorentz DC pump through an MPPT controller. Performance was evaluated through simulation and field monitoring. Key parameters assessed were flowrate, hydraulic energy, wire-to-water efficiency, motor efficiency, and daily pump operating hours. The pump operated 07.00–16.00 WITA, slightly earlier than the simulated 08.00 start time. The average monitored flowrate (1.07 m³/h) closely matched the simulated value (1.08 m³/h). Monthly average output was 10.75 m³ (monitoring) versus 10.83 m³ (simulation). The PV system produced 7.34 kWh/day, yielding a yield factor of 3.06 kWh/kWp/day. Hydraulic energy output was 3.31 kWh/day, resulting in overall system efficiency of 26–30%, consistent with typical Lorentz DC pump performance. System performance aligns well with simulation predictions. Operation is strongly influenced by irradiance, ambient temperature, total dynamic head, and well characteristics. The SWPS demonstrates reliable performance for remote clean-water supply in Sumba.