An in-use Comparative Analysis of Diesel, CNG, and Electric Buses for a Small Island Developing State

The transition to sustainable transportation is a critical challenge for Small Island Developing States (SIDS), which face unique constraints related to energy resources, high fuel costs, and climate change vulnerability. While battery electric buses (BEBs) are increasingly seen as a viable solution, research comparing their operational and economic performance with diesel and compressed natural gas (CNG) buses in SIDS remains scarce. This study addresses this gap by employing a novel methodology that integrates real-world telematics data from a pilot fleet of diesel and CNG buses with a comprehensive cost–benefit analysis (CBA) in a Caribbean SIDS. The analysis reveals that approximately 80% of daily routes are within the range of a representative BEB, supporting overnight depot charging as a feasible strategy. However, route-specific assessments suggest that certain high-demand routes may require opportunity charging to ensure operational efficiency. The financial modelling under various fuel and electricity price scenarios demonstrates significant cost savings for BEBs over their operational lifespan, with competitive payback periods that justify the higher initial investment. Furthermore, BEBs show a substantial reduction in greenhouse gas emissions compared to diesel and CNG alternatives, reinforcing their environmental benefits. These findings provide valuable, data-driven insights for SIDS policymakers and transportation planners, highlighting the viability of BEBs as a cost-effective and environmentally sustainable alternative for public transportation systems in resource-constrained environments.