System of use of electric energy regenerated by a train or available in catenary, by an electric vehicle, and associated procedure. System and procedure for utilization of regenerated electrical energy during the braking stage of at least one train (1) belonging to a train network or available in a catenary, by at least one electric vehicle (2); wherein said utilization system comprises an accumulator element (3) of the electrical energy regenerated by said train (1) and supplied through a catenary (7); a charging point (4) in direct current connected to said accumulator element (3), and configured to supply electric power to said electric vehicle (2); and a control subsystem (5) configured to manage the flow of electrical energy from said accumulator element (3) to the charging point (4) of the electric vehicle; configuring all this a system capable of using existing infrastructures at present, guaranteeing an economic cost of low implementation, and a high energy performance of operation. (Machine-translation by Google Translate, not legally binding)