Optimal sizing of Distributed Energy Resources (DERs) in a typical microgrid is a complex multi-objective problem. The multi-objective optimization problem modeling plays important role in DERs planning. In this paper, the Pareto front solutions is proposed as a multi-objective problem formulation in order to optimal sizing of DERs. Based on Pareto front solutions each objective function has a dimension and considered independently. As a result all of the objectives effect in planning problem as important as it is. Investment costs, emission pollution and power loss considered as three objective as well as three dimension in this paper. The DERs planning formulated as an optimization problem that solved using Genetic Algorithm (GA) under technical and economic constraints. The proposed methodology is applied to a typical microgrid under both grid connected and standalone operation modes. The simulation results show the effectiveness of the proposed methodology.
