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.
