Sustainable tramway, techno-economic analysis and environmental effects in an urban public transport. A comparative study

The problem of climate change because greenhouse gas emissions is aggravating, especially in public transport, which encourages the development of new technologies and clean energy control methods for the propulsion of vehicles such as tramways. A new energy control for a real tramway has been proposed in this paper, combining renewable sources, supercapacitors and lithium ion batteries, both components will absorb the energy from the regenerative braking of the tramway. The system has been modeled in Matlab considering certain restrictions in each component in order to supply the load on the round trip. Finally, a techno-economic and environmental analysis has been done identifying new patterns with respect to existing tramway systems. The annual energy required by the tramway is 867.62 MWh/year. The power variations are mainly supplied by the supercapacitor and the lithium ion battery functions as a backup. In this regard, the proposed system saves $ 2205,724 by supplying energy to the tramway and selling the excess energy to the grid for 20 years. Finally, the renewable system will have avoided 8445.4 tCO₂/MWh.