Well-to-wheel analysis for electric, diesel and hydrogen traction for railways

This paper derives the energy efficiencies and CO2 emissions for electric, diesel and hydrogen traction for railway vehicles on a well-to-wheel basis, using the low heating value and high heating value of the enthalpy of oxidation of the fuel. The tank-to-wheel and well-to-tank efficiency are determined. Gaseous hydrogen has a WTW efficiency of 25% low heating value, if produced from methane and used in a fuel cell. This efficiency is similar to diesel and electric traction in the UK, US, and California. A reduction of about 19% in CO2 is achieved when hydrogen gas is used in a fuel cell compared to diesel traction, and a 3% reduction compared to US electricity.

► The paper derives well-to-wheel efficiencies and CO2 emissions of electric, diesel, and hydrogen, railway traction systems. ► The well-to-wheel efficiency of vehicles powered by gaseous hydrogen from natural gas is similar to diesel and electric. ► Hydrail has lower CO2 emissions than diesel if H2 is produced from natural gas; higher reductions with H2 from renewables. ► Hydrail efficiency similar to electric if power source solar and transport 5000 to 7100 km, otherwise H2 efficiency higher.