Hierarchical analysis of US electric vehicle subsidies for carbon emission mitigation

• Hierarchical analysis shows EV subsidies can cut US emissions significantly. • Emission reduction subsidy costs range from $1167.44/ton to $6880.13/ton by state. • Tiered federal subsidies could increase emission reductions by 15.27%. • Subsidy restructuring promotes cleaner grid energy and extends battery life. Electric vehicle (EV) adoptions are promoted with subsidies to reduce greenhouse gas emissions from ground transportation. In this paper, a hierarchical analysis is presented on the potential of greenhouse gas emission mitigation via the electric vehicle subsidy policy at state level in the US, through research of environmental and economic fundamentals of electric vehicle operations, energy consumptions, battery degradation and service life. It has been found that restructuring the federal subsidies to promote EV adoption can significantly reduce greenhouse gas emissions across the US. The reduction costs of greenhouse gas emissions vary between $1167.44/ton in Vermont to $6880.13/ton in Wyoming. A case study reveals that 15.24 % more greenhouse gas emissions can be reduced with a tiered federal subsidy structure. The restructuring of subsidies will also encourage the adoption of clean energies in the grid fuel mix and drive technological advancements to extend the battery lifetime in the future.