Solar photovoltaic (PV) system is one of the matured solar-to-electricity conversion technologies with a great potential for residential applications. For wider adoption of PV systems, there is a need for an accurate sizing and economic assessment tool to inform decision makers. In this study, we propose a new optimization model based on integer programming for the adoption of stand-alone PV systems in the residential sector. The proposed model not only determines the optimal number of PV modules and batteries but also assesses the economic feasibility of the system through annualized cost. The model takes into account site-specific data in finding the optimal sizes. The effectiveness of the proposed model is assessed through a case study in Bursari, Nigeria. The result obtained from the model reveals that establishing a solar PV system is not only environmentally friendly but also about 30% cheaper than the diesel generators that are currently in use at Bursari. In particular, annually about 361 USD per residential building could be saved if the proposed system is used to replace the diesel generators. Finally, this study also, provides valuable managerial insights about the effect of several parameters on the performance of the proposed PV system. (C) 2017 Elsevier Ltd. All rights reserved.