Solar energy is effectively used to power stand-alone photovoltaic pumping systems (PVPSs) for irrigation and drinking purposes in remote areas. However, random vicissitudes and the unpredictability of the amount of solar energy that can be harnessed lead to difficulties in designing PVPS. Thus, an optimal sizing approach is essential to ensure satisfactory performance. In this paper, a numerical iterative sizing approach based on technical and economic objectives is developed to optimize the configuraion of PVPS. The loss of load probability criteria is considered as the technical objective, while the life cycle cost criteria is considered as the economic objective. The proposed pumping system provides a daily water for a small village in Kuala Lumpur, Malaysia. The proposed sizing approach is used to test all the possible configurations of a wide range of photovoltaic (PV) array sizes to specify the PV array configurations that realize the reliability condition. The optimal size of the storage tank and the optimal number of PV modules connected in series and parallel are specified to keep up a balance between the loss of load probability, life cycle cost, and excess water volume of PVPS. The performance of the system is tested on the basis of the proposed optimal configuration and hourly meteorological data for 1 year. The results show that the proposed system is available throughout most of the year. Copyright © 2017 John Wiley & Sons, Ltd.