Enhancing Stand-Alone PV Pumping Efficiency: An Experimental Study of Low-Tilt Angle Optimization in Southern Hemisphere Season

Articles in Press

Document Type : Research Article

Authors
Ahmad Agus Setiawan 1
Apri Tri Nugroho 2
Dinda Al Humam Annajmi 1
Rosyid Rizkiyanto Jati 2
Miharza Irfandi 2
Budiyono Budiyono 1
Wahyudi Maulana 1
1 Department of Nuclear Engineering and Engineering Physics, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia
2 Master’s Program in System Engineering, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia
10.22059/jser.2026.410950.1719
Abstract
This experiment investigates the performance optimization of a stand-alone photovoltaic water pumping system (PVWPS) in the tropical region of Yogyakarta, Indonesia (7°S latitude), specifically during the December Solstice. While conventional designs often utilize fixed latitude-based tilt angles, this research proposes a seasonal micro-adjustment strategy to address the sun's extreme Southern position during the rainy season. An experimental comparison was conducted between two low-tilt configurations (5° vs. 10°) on a 1.65 kWp off-grid system powering a 290 W surface pump. Data were collected under real operating conditions (10:00–14:00) and filtered to exclude cloud-edge anomalies. The results disclose that the 5° tilt angle outperforms the 10° configuration, achieving an average electrical efficiency of 17.5% compared to 16.6%. The near-flat orientation minimizes cosine losses and maximizes direct irradiance capture when the sun is at the Tropic of Capricorn. This study recommends a seasonal manual adjustment to 5° during the December planting season to enhance water discharge reliability in remote agricultural areas.
Keywords
Solar water pumping
Tilt angle optimization
Seasonal adjustment
Stand-alone PV
Tropical climate
Energy efficiency
Journal of Solar Energy Research

Articles in Press, Accepted Manuscript
Available Online from 07 August 2026