In this paper optimal placement of energy storage devices in low voltage distribution networks is investigated. The main target of this study is to find the optimal place, along with the related management strategy, of an energy storage device to maximize loss reduction in the network. The objective function involves the losses amount during all time intervals. Particle swarm optimization (PSO) algorithm has been applied for finding the solution of this problem. Among the most important features of this algorithm stands its feasibility, regarding both ease and speed. CIGRÉ low voltage network has been selected to evaluate the effectiveness of the method.