In recent years, grid integration of renewable energy sources (RES) and battery energy storage systems (BESS) has been rising rapidly. Many economic, technical, and environmental benefits can be gained with the integration of RES and BESS into the distribution network. Optimal decisions must be considered the trade-offs between two or more conflicting objectives, therefore, in this paper, these benefits are associated with a multi-objective function that consists of energy price arbitrage, transmission access fee, energy losses, power quality (voltage regulation), and environmental emissions. In this paper, it is assumed that the distribution system operator (DSO) has got the ownership of RES and BES. The placement, sizing, and operation of RES and BESS are optimized by the combination of a genetic multi-objective solver (GMOS) with linear programming. The simulation results using IEEE 33-bus distribution test system show that by using the proposed method, the net benefit is appropriate, energy losses are reduced, voltage magnitude is pushed within the limit, and environmental emissions are decreased.