Assessing the cold weather impact on battery electric transit buses

This study investigated the impact of cold weather on the energy performance of battery-electric buses (BEBs), using a real-world dataset from seven BEBs operating over two years across complex 41 routes in Tompkins County, New York. Novel Optimal Temperature Zone (OTZ) baseline models were developed to estimate BEB performance under ideal temperatures, and a comprehensive assessment of cold weather effects was conducted. Findings showed that the total energy consumed and regenerated increased by an average of 48.0 % in the −4 °C to 0 °C range, compared to the OTZ baseline prediction for the same trips, where the OTZ is defined as 16 °C to 30 °C. Across the broader –12 °C to 10 °C range, the average increase was 28.6 %. We elucidated the roles of different vehicle components (e.g., the charging efficiency of regenerative braking, battery heating, HVAC systems) in the impact of cold weather on energy performance, considering urban vs. rural differences and operating conditions. Recommendations were provided for BEB operators and manufacturers to improve efficiency in cold climates, and vital insights were offered for policymakers to develop effective transit electrification strategies in cold weather.