Optimization methodology of infrastructure and onboard energy storage system for cost-reduction in tramway lines design

Nowadays, friendly urban-adapted railway vehicles are required, in this matter, manufacturers are committed to develop more efficient and cost-competitive mobility solutions. The search of the most competitive solution takes on high important when the Onboard Energy Storage Systems (OESSs) become part of the project equation due to the additional cost they represent over a conventional tramway, but also the economic saving they allow from the electrification point of view. This paper proposes an optimization methodology for tramway lines design to find the optimal combination of infrastructure required for electrification (sections with/without catenary, opportunity charging points location, substations and civil work related with them) and OESS sizing aiming to minimize the total operation cost of the project. The methodology includes technical, economic and lifespan estimation (OESS) models considering the whole project lifetime. To customize the tramway solution to each scenario, three optimization modes have been defined: ESS sizing, opportunity charging point location, and whole scenario optimization (infrastructure and OESS sizing). The proposed methodology and customization analysis are applied on a real case study of the tramway of Zaragoza, Spain.