A Solid Oxide Fuel Cell-Gas Turbine Hybrid System for a Freight Rail Application

The simulation of a Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) hybrid system for a locomotive application is presented. Using Matlab Simulink, a 2.8 MW SOFC system was combined with a 500 kW GT and simulated to travel the route from Bakersfield to Mojave in California. Elevation data was imported using the Google API Console and smoothed in order to calculate the dynamic power demand for the SOFC-GT system, assuming 480 tons of freight per 120 ton locomotive traveling at an average speed of 45 mph. The SOFC-GT system model follows this demand without causing a significant disruption to the speed of the locomotive. A lithium-ion battery was included into the system model to improve the net system efficiency and make the operation smooth enough for the highly dynamic route. The overall efficiency along the simulated route has been calculated as 57% operating on partially pre-reformed natural gas fuel. These results suggest the development of a physical prototype of the simulated system and are very promising for the future of freight rail transportation throughout the US. CO2 and particulate matter emissions are significantly reduced compared to current diesel-electric locomotives and it is also possible to operate the system on hydrogen, i.e., completely emission-free. A techno-economic analysis to assess the economic feasibility of this system is currently being prepared.