Performance of a Direct-Coupled Photovoltaic Water Pumping System Driven by Inclined North-South Axis Three-Position Solar Tracker

Abstract

Due to the complexity of traditional continuous tracking mechanisms, most installations for small-scale photovoltaic water pump systems (PVWPS) are stationary and oriented due south. The aim of this study is to evaluate the performance of an affordable, easy-to-operate tracking method for small farmers to promote the sustainable use of photovoltaic energy. Experiments are conducted to evaluate the performance of small-scale PVWPS driven by inclined north-south axis three-position (INSA-3P) solar tracker, which requires only yearly four tilt adjustments and daily three azimuth adjustments. This INSA-3P photovoltaic (PV) system is respectively compared with a fixed system and a manual two-axis (2A) tracking mode under typical sunny conditions in Kunming throughout the year. Two identical systems for comparison both consist of a 100 W pump and a 100 W PV module. The findings in Kunming's climate reveal that the INSA-3P tracking system significantly outperforms the fixed system, achieving 1.56, 1.61, 1.75, and 1.60 times higher daily water pumping capacity during winter, spring, summer, autumn. It is worth noting that INSA-3P tracking PV system can be manually implemented by adjusting the module's orientation three times a day to follow the sun's path, yielding over 96% of the daily water pumping capacity of 2A tracking PV system.