In this paper both DC and AC railway electric power feeding systems are reviewed and discussed. The advantage and disadvantage of these systems are also compared. One major problem of such systems is that they take the lion share of electricity consumption compared to non-traction systems. Therefore, most of the new technologies focus on enhancing Energy efficiency of railway systems. This paper discusses the main operation methodologies for reducing the consumption of electric traction systems. These methods include using renewable energy resources (RER), such as solar Photovoltaic (PV) panels and wind turbines, and regenerative braking. Moreover, the most common energy storage devices such as batteries, super-capacitors and flywheels. They are used in railway systems for storing the excess energy from RER or the return energy during regenerative braking (Batteries, super-capacitors and flywheel) are also explained. In addition, challenges of the right storage system selection for specific applications are briefly discussed.