The possibility to regenerate and store braking energy of electric vehicles is a relevant way of energy saving. The main types of application methods of energy storage devices for grid-supplied electric public transports are: the placing of mobile energy storage devices on board; the placing of stationary energy storage devices along the grid or in substations. In order to determine which type is more beneficial in certain situations, calculations must be performed. Energy losses in case of carrying stationary storage devices and transmission line losses in case of transferring regenerated energy to stationary storage devices should be clarified. Possibilities to use variable resistance resistors for virtual simulations of DC transmission line losses is described and analyzed.