In this paper, the stationary super-capacitors are used to store a metro network regenerative braking energy. In order to estimate the required energy storage systems (ESSs), line 3 of Tehran metro network is modeled through a novel approach, in peak and off-peak conditions based on the real data obtained from Tehran metro office. A useful method is proposed to predict the maximum instantaneous regenerative energy which is delivered to each station before applying ESS and based on that the ESS configuration for each station is determined. Finally, the effectiveness of the proposed ESS is confirmed by economic evaluations and benefit/cost analyses on line 3 of Tehran metro network. (C) 2011 Elsevier Ltd. All rights reserved.