Energy performance indicators as policy support for public bus transport – The case of Sweden

•Four different energy performance indicators of public bus transport are discussed.•Regional differences in fuel use are strongly correlated with the propulsion systems.•A life cycle view is necessary to estimate the environmental impact of fuel use.•Fuel efficient buses may still have a high WTW energy use and environmental impact.•Biogas is more efficient than other alternative fuels in reducing GHG emissions. The share of renewable fuels in Swedish public transport is steadily increasing, in line with European energy and climate goals as well as a national goal of a fossil-free vehicle fleet by 2030. However, the progression towards this goal is quite different among the Swedish regions, and efforts have been made on a national level to compare the public bus transport systems and provide a foundation for policymaking. This paper investigates different ways of assessing and presenting the energy performance of public bus transport systems. The analysis includes use of renewable and fossil fuels as well as energy efficiency and its underlying factors. Various energy performance indicators are presented and discussed with regards to practical implications and applicability for policy support. A life cycle perspective on fuels (“well-to-wheel”) is found to have clear advantages when it comes to global reductions of fossil energy use and emissions. This requires detailed information about the fuel use, which is not always the case with the existing reporting system. Setting the energy use in relation to number of passengers transported rather than just the distance covered would better reflect the function of the transport system, but is also more uncertain with the current data available.