Comprehensive energy assessment of battery electric buses and diesel buses

Abstract

The drive to ban diesel vehicles is well underway in several major European cities with the aim of improving air quality and reducing greenhouse gas emissions, and similar plans have been announced by authorities around the world. This poses a major challenge for the public transport sector given its high reliance on diesel bus technology. Zero-emission battery electric buses (BEB) currently stands as one of the most promising solutions for reducing the overall carbon footprint of public transport, especially with the continuous improvements in electric powertrain and battery technologies and costs. This paper presents a detailed comparative energy assessment between BEB and diesel buses (DB) operating at various driving and weather conditions. The different energy loads encountered in bus operation, including those needed for traction, air conditioning and operation of other electric, hydraulic and pneumatic auxiliaries are all considered in this study. Simulation results show that BEB consumes 2-4 times less energy compared to DB depending on the operating conditions where almost 80% of the energy saving is obtained from the reduction in the traction load.