Analysis and comparison of energy efficiency of commercially available battery electric buses

Battery electric buses have been tested in Helsinki region to gain experience on the actual energy consumption and how well they suit for the Finnish climate. Measurements were performed on a chassis dynamometer with various driving cycles and gross vehicle weights in order to be able to analyse the buses in detail. The measurements reveal significant differences in the energy consumption of the buses. The sensitivity to different cycles and loads also varies greatly. The observed differences can partly be explained by the different curb weights of the buses. Another reason for the differences is the regeneration rate, which was as low as 15% for some buses, while the best bus was able to regenerate over 35% of the energy