Seasonal energy efficiency: a case study of an urban distribution battery electric truck operating in Brazil

Electric heavy-duty trucks, fully powered by batteries, are nowadays a reality in cities across Europe, North America, and China. This movement is driven by stringent CO₂ emission regulations, which advocate for zero greenhouse gas emissions in the road transportation sector, thus promoting the development of battery-powered electric trucks. From the point of view of operational cost and technology adoption by fleet owners, it is of great relevance to assess energy efficiency of battery electric heavy-duty trucks under real-world driving conditions. In this regard, an experimental evaluation of the seasonal energy variation of a battery electric heavy-duty truck is presented in this paper. The chosen battery electric truck ran daily on a predefined route in the São Paulo metropolitan region during nearly eight months to embrace different operational and weather situations. Energy consumption parameters were obtained from different Electronic Control Units of the battery electric heavy-duty truck, which allowed us to estimate, e.g., the actual energy consumption and the energy consumed by the drivetrain along with electric machine losses under varying weather situations, as well as to calculate, e.g., the energy efficiency for the propulsive and regenerative operation modes. In sum, the road test results indicate that energy consumption reduces as the ambient temperature falls, energy supplied to the electric machine and mechanical parts decreases as the ambient temperature drops, and energy efficiency in both modes reduces as the temperature rises.