The article describes core criteria, which define efficient application of energy accumulators in railway traction power supply system. Installation points for energy accumulators in electric power system of train electric drivers, where application is most effective, are identified. These points are railway sub-stations, electric traction network and traction power system. The main types of energy accumulators, which essentially can be used on railway transport in traction power system – traction sub-stations and traction network, electric motive power, are examined. They can be used on railway transport and. The quality factors of work for traction energy power and electric motive power are presented, improvement of which can be performed using energy accumulators. International experience of energy accumulators application for railway transport is presented. Russian developments and implementation of energy accumulators from domestic manufacturers are examined, both in the traction power system and in the electric rolling stock. The polygons for the most efficient use of energy storage in the traction power supplying system are identified.