Zero carbon energy storage options for intermodal freight trains

Replacing the energy density and convenience of diesel fuel for locomotives in freight operations present considerable challenges. Design requirements are explored using train dynamics simulations to establish energy needs. The test case was a freight train of 3030 gross tonnes consisting of two locomotives and thirty wagons operating on a relatively flat coastal rail route and on uphill and downhill routes simulation mineral unit trains. 

Assuming use of existing and near market technologies, speculative locomotive designs were proposed for both battery-only and hydrogen-battery systems. The results showed that full recovery of dynamic braking energy required only a very small amount of storage to capture and allow re-use, typically only 6% of the trip total of recovered energy. The large mass of batteries needed to power the whole trip, however, was found to limit the practical operating range and or train size. The results containment systems have large mass, the space and mass requirements for a hydrogen system could be as low as half that required for batteries, with options to further reduce space requirements with higher pressure or cryogenic options.