Performance of submersible PV water pumping systems in Tunisia

Abstract

Water pumping system is one of the most economically viable photovoltaic applications in remote areas especially in developing countries. For the favorable solar radiation conditions in Tunisia (3000h of solar radiation per year) and an average daily solar radiation intensity exceeding 6kWh/m2/day, solar water pumping for domestic use, for irrigation and cattle watering can be critically important, and the value of a PV water pumping system in these circumstances can far exceed its costs.Four NE 42-30 Pleuger submersible pumps were installed at four different locations in the region of Kairouan (36.5° N, 10.11° E), 150km south of Tunis. Three of these pumps were supplied by 2.1kWp AEG PV modules, while the fourth was supplied by 2.8kWp AEG PV modules.Prior to its installation, the subsystem (inverter, motor and pump) had been tested with a linear source in accordance with frequency and head. The subsystem starts when its output frequency and voltage achieve 35Hz and about 60% of the nominal voltage of the asynchronous motor.As illustrated in this work, performance tests (with linear source) and performance tests (with PV source) carried out while operating the system under local climatic conditions are well matched. At constant head pumping, the maximum overall efficiency of the system is 3.7% and the mean efficiency over this period is 2.5%.