Regarding the importance of supplying energy to regions that are far from power systems, this study is devoted to analyzing and modeling of a stand-alone micro-grid. In spite of many studies in the case of demand response programming for optimal management and operation cost reduction of the micro grids, and regarding the importance of size optimization of micro-grids, this paper seeks to examine and investigate the ability of demand response programming in the case of component size optimization of a micro-grid. Due to deficiency or unavailability of dispatchable energy recourses, only the nondispatchable renewable energy resources (wind and solar energy) are considered to supply the required energy. Applied strategy for effective component size optimization as well as relevant costs reduction is implemented by reducing or eliminating the mismatch between the generation and consumption profiles by time shift and schedule of dispatchable loads. Furthermore, the effect of demand response utilization on loss of generated energy reduction is studied. The optimized results with and without demand response are extracted and compared to each other. For each case, the optimum configuration was determined. Obtained results indicated that application of the demand response program, reduced the number of required batteries, the required inverter and photovoltaic cells capacity, and, consequently, the total net present costs. Furthermore, demand response implementation reduced the peak of consumed loads and increased the consumed load factor and correlation factor. The micro-grid components have been modeled mathematically within the framework of the mixed integer linear programming method. The optimization program has been performed by HOMER software together with GAMS software via the CPLEX solver. (C) 2017 Elsevier Ltd. All rights reserved.