Modeling and understanding the impacts of efficiency measures on fleet fuel consumption in vehicle importing countries: A case study of Qatar

Globally, transportation always rank in the top three emission sectors next to industry and buildings sectors. Thus, any efforts to achieve efficiency would lead to significant reductions in the emissions. Transition to new technology vehicles with clean and alternative fuels is an important way of achieving such emission reductions. Countries that import vehicles rely on the technology improvements and laws of other countries to increase the fuel efficiency of their vehicle stock. This research investigates the impact of such a scenario by considering the case study of Qatar, which is a country that is oil- and gas-rich and imports all of its vehicle stock. The model developed in this study, by the combined use of system dynamics and vehicle cohort modeling, is the first of its type in this region. Moreover, it addresses the research gaps by comparing the market penetration and sales of gasoline, hybrid-electric, and battery electric vehicles. The results reveal that despite alternative vehicles dominating the sales, gasoline vehicles have remained in the stock for more than 10 years after the complete stoppage of their sales. This is because of the system inertia created by the volume of vehicles in stock owing to their long lifetime. Nonetheless, in the extreme scenario of battery electric vehicles dominating the market, hybrid-electric and battery electric vehicles significantly reduce fuel consumption and emissions, with an estimated emission reduction of more than 8 million tons of carbon dioxide. These savings are not at the same level in terms of the fuel because one (gasoline) vehicle is replaced by another one (in which electricity is generated via natural gas), with the electricity consumption increasing by more than 8 TWh.