The photovoltaic water pumping systems (PVWPS) is considered as one of the most promising areas in photovoltaic applications. The aim of this work is to determine the effect of pumping head on PVWPS using the optimum PV array configuration, adequate to supply a DC Helical pump with an optimum energy amount, under the outdoor conditions of Madinah site. Four different pumping head have been tested (50 m, 60 m, 70 m and 80 m). The tests have been carried for a different heads, under sunny daylight hours, in a real well at a farm in Madinah site. The best system efficiency has been obtained for the head of 80 m which is recommended for SQF submersible pump for a deep head. Also, the flow rate Q depends basically on two factors: the pumping head H and the global solar irradiation Hg. The model developed should be able to predict the flow rate Q for any head chosen with a best accuracy. (C) 2013 Elsevier Ltd. All rights reserved.