Alternative Powertrains for Non-Electrified Railways: A Comparative Case Study

The focus of the paper is the comparison of different powertrain for non-electrified and partially electrified railway lines, such as the Milano-Lecco in Italy. This study models and simulates the baseline case of a diesel-electric train against three alternatives using the Modelica language: two series hybrid electric vehicles (SHEV-A and SHEV-B) with varying engine sizes, and a pure battery electric vehicle (BEV). Powertrain hybridization led to interesting savings in terms of diesel consumption, due to regenerative braking and a more efficient use of internal combustion engines. However, best results in terms of air emissions and energy operational cost have been reached by BEV solution: CO2 emission are reduced by -78% and specific cost per km by a remarkable -66%. A simple economic analysis in terms of cumulated cashflow over 10 years, confirmed that the higher initial investment of the BEV version is paid back within a few years. Economic performance is obviously affected by energy commodities price, but with current prices, BEV led to total savings of 1.22 million of a after 10 years.