ABSTRACT
A field trial procedure has been designed to evaluate the performance of photovoltaic (pv) water-pumping systems under natural environmental conditions. The procedure is presented in a manual format with the intention that it be used by field engineers or laboratory researchers as a reference guide. Directly connected pv water-pumping systems operate under variable conditions of energy supply. Fluctuations in solar irradiance, the main source of its energy, sets the operating point of the directly connected motor–pump system in continuous motion along its output characteristics curve. The most important consideration in system design is the match between the motor–pump system and the solar array; that is, the operating point of the motor under load must correspond to the locus of maximum-power points of the array over the majority of the motor speed range.
