Energy is one of the most important requirements in development of societies. In the last decade, widespread attention has been paid to renewable energies. Despite the obvious advantages of renewable energy resources, their dependence on climate change is one of the most fundamental problems facing to the development of them. Optimal design of hybrid renewable energy systems is a major issue in power systems. In this paper, a new unit sizing method is considered for stand-alone hybrid renewable energy systems in order to maximize the electricity match rate between demand and supply intervals in lowest cost. This work is undertaken with triple objective function: inequality coefficient (IC), correlation coefficient (CC), and annualized cost of system (ACS). The reliability of the system is investigated by using the Loss of Power Supply Probability (LPSP) function. Weather data and load demand are collected from a small village in southeastern Iran, as a case study. A suitable control algorithm has been designed for the system which can decide to start the diesel generator or use the battery power when the total output power from the system cannot meet the load demand. The results of this study are valuable for implementation of future hybrid renewable energy system in any location; making best use of resources and maximum economic efficiency.