Exploring a case transition to low carbon fuel: scenarios for natural gas vehicles in Irish road freight

To attain emissions reduction targets within lagging transportation areas, several alternative fuel technologies such as methanol, natural gas, electric, hydrogen and biofuels have been suggested to replace conventional gasoline-powered vehicles at different points. In the process, several policies have been implemented and assessed in attempts to stimulate the diffusion of cleaner alternative vehicle technologies. This study seeks to explore the effect of some of these policies on driving vehicle switching within the Irish road freight. An agent-based model (ABM) is developed to evaluate the relative policy effect on natural gas vehicle (NGV) switching. More specifically, the model focuses on vehicle features and payback decision as conditions with the potential to impact natural gas vehicle switching. A simulation was performed over 13 years with the base year of 2017 running towards the 2030 vision. Initial findings indicate opportunities for NGVs with regards to a few determinants, which include vehicle switching population, gas demand, carbon (CO2) savings and incentive costs. In a ‘business as usual payback’ scenario with a carbon tax levy of €20/CO2 tonne(t), these opportunities decline with a reduction in vehicle weight category and kilometres travelled, requiring the intervention of supporting policies such as subsidy provision and improved fuel price gaps through increasing CO2 tax rates per tonne (€20-€100/CO2 tonne). Based on the observed emissions savings, natural gas is recommended as a bridging path towards renewable fuels integration in road freight, if significant emissions reduction is to be achieved.