Methodologies to identify non-electrified railway lines to be converted to hydrogen

Although the rail transportation system is generally considered to have one of the lowest environmental impacts, this is not always true. Indeed, in the case of non-electrified railway lines, the propulsion system typically is based on diesel engines. The commonly adopted solution to improve the environmental sustainability of a diesel rail line is its electrification, which consists of constructing the overhead line, installing the related substations, and replacing and upgrading the rolling stock. However, in some cases, the electrification costs may not be justifiable due to the low number of passengers served by the considered line. In these cases, the conversion to hydrogen may be considered as an intermediate solution to the problem. In this context, the paper proposes a methodology to identify non-electrified rail lines that could potentially be converted to hydrogen propulsion.