Carbon emission reductions in the University of São Paulo’s transportation sector using hydrogen-powered vehicles

Abstract

The transportation sector, especially diesel-powered buses in Brazil, faces a significant decarbonization challenge, contributing with 19.76 million tCO2-eq GHG emissions. Therefore, this study aims to calculate the achievable GHG emission reductions by implementing renewable hydrogen vehicles at the University of São Paulo. The methodological approach considers low-carbon hydrogen production using the ethanol steam reforming route, where energy and mass balances are performed throughout the hydrogen chain. Two models are developed to calculate CO2-eq emissions. Results show that replacing the current fleet of conventional internal combustion engine buses with hydrogen-based options leads to a significant annual reduction of 2658 tCO2-eq, approximately an 83% reduction as compared to the conventional one. Moreover, the total energy conversion efficiency, well-to-wheel, reaches 26.9% and 11.8% for hydrogen and conventional vehicles, respectively, without air-conditioning system, or 21.9% and 9.9% when air-conditioning is coupled, respectively. Notably, CO2-eq emissions increase by at least 38.3% and 15.5% due to the presence of that equipment, respectively. Finally, the results of total cost of ownership (TCO) showed that CAPEX represents only 7.14% of the TCO, being the fuel cost the major proportion for both technologies.