Real-world final-energy and operational-emissions comparison of diesel and battery-electric intercity buses on a matched Belize corridor

This study uses field data to compare diesel and battery electric intercity bus performance on the Benque Viejo-Belize City corridor in Belize. The matched observational sample included one diesel bus and two battery electric buses. Performance was evaluated using directly measured fuel and battery energy converted to MJ/100 km, with checks for common calendar dates, operating conditions, kinematics, grid adjusted operating emissions, source energy, and weather. Across the matched corridor, weighted mean direct energy intensity was 1716.7 MJ/100 km for diesel service and 344.5 MJ/100 km for electric service, equivalent to a 79.9% reduction in direct vehicle energy demand. The result remained stable across 115 dates on which both technologies were observed. Under the main Belize average grid scenario, operating CO₂ intensity for the matched electric corridor was 324.4 g/km, compared with 1285.1 g/km for diesel tailpipe CO₂. The findings provide corridor specific evidence that battery electric intercity buses can deliver large direct energy and operating emissions reductions under the observed Belize conditions, while wider claims about national scale up, operating sufficiency, cost, and life cycle emissions require larger samples and additional system data.