Pareto Optimization of the Integration of Renewables for the Supply of Battery-Electric and Hydrogen-Electric Multiple Units at a Single Site

Abstract

Battery- and hydrogen-powered trains are emerging technologies that have the potential to play a key role in the decarbonization of railway lines for which full trackside electrification is not feasible. In this study, we examine Pareto-optimal energy supply concepts for a specific location along the Cologne–Gerolstein railway line. We investigate two supply concepts, one for battery trains making use of overhead line islands (OHLIs), referred to as the OHLI supply concept, and another for hydrogen trains that make use of hydrogen refueling station (HRSs), referred to as the HRS supply concept. The public grid, as well as renewable energy sources such as wind and PV energy, are considered sources of electrical energy supply. The sizing of these takes into account storage technologies and load time series specific to each supply concept. Simulation models are defined to evaluate the characteristics of an OHLI and HRS supply concept located in a small town (Gerolstein, Germany). Our findings indicate that the HRS supply concept results in more than twice the cost per MWh (111%/MWh higher) compared to the OHLI supply concept. However, the HRS supply concept achieves a 24.7% higher degree of self-sufficiency. Furthermore, the HRS supply concept requires a larger energy system in terms of installed renewable power and storage capacity. This enables the HRS to supply the entire line with energy, whereas the OHLI supply concept covers only a share of the overall energy demand of battery trains at the location under consideration. The remaining energy demand is covered by existing overhead lines or OHLI at another location.