Cost modelling-based route applicability analysis of United Kingdom passenger railway decarbonization options

•Developed cost model for railway decarbonization upgrade options, including operating, rolling stock upgrade, infrastructure construction, and maintenance support costs.•An adaptive particle swarm optimization is used to find the minimum cost of three decarbonization options.•The experiment determined the traffic density range in which hydrogen fuel cell trains, battery trains, and electrified trains have cost advantages over various distances.•Rule-based state machine energy management strategies are used to find the appropriate power allocation scheme for hydrogen fuel cell trains, considering the energy conversion efficiency of hydrogen fuel cells and the state of charge of the batteries.•The main defects of hydrogen fuel cell trains and battery trains were analyzed, providing insights for guiding their future commercial development. The UK government plans to phase out pure diesel trains by 2040 and fully decarbonize railways by 2050. Hydrogen fuel cell (HFC) trains, electrified trains using pantographs (Electrified Trains), and battery electric multiple unit (BEMU) trains are considered the main solutions for decarbonizing railways. However, the range of these decarbonization options’ line upgrade cost advantages is unclear. This paper analyzes the upgrade costs of three types of trains on different lines by constructing a cost model and using particle swarm optimization (PSO), including operating costs and fixed investment costs. For the case of decarbonization of the London St. Pancras to Leicester line, the electrified train option is more cost-effective than the other two options under the condition that the service period is 30 years. Then the traffic density range in which three new energy trains have cost advantages on different line lengths is calculated. For route distances under 100 km and with a traffic density of less than 52 trips/day, BEMU trains have the lowest average cost, while electrified trains are the most cost-effective in other ranges. For route distances over 100 km, the average cost of HFC trains is lower than that of electrified trains at traffic densities below about 45 trips/day. In addition, if hydrogen prices fall by 26 %, the cost advantage range of HFC trains will increase to 70 trips per day. For route distances under 100 km, BEMU trains still maintain their advantages in terms of lower traffic density.