Technical and economic feasibility of increasing tram system efficiency with EV batteries

Separate and common overhead catenary systems (OCS) are widely utilised on urban light-rail systems. This paper applies Simulink modelling to investigate differences in energy efficiency between two OCS systems, applied to a typical urban tram system. Results suggest common OCS reduces energy demand by 14%, as availability of regenerative braking increases by 297%. This paper predicts number, capacity and best installation locations for energy storage systems (ESSs) on an example system. Greater energy efficiency is achieved by installing ESS on centre stops between adjacent substations, rather than substation stops. Further, an economic study considers net present value, internal rate of return and payback period for a given ESS capacity; and a sensitivity analysis identifies capital cost and battery life as the most influential parameters to economic viability. Finally, using parked EVs as ESS for a tram system is explored to improve the economics.