Greenhouse gas emissions of conventional and alternative vehicles: Predictions based on energy policy analysis in South Korea

Abstract

This paper compares the well-to-wheel (WTW) greenhouse gas (GHG) emissions of representative vehicle types–internal combustion engine vehicle (ICEV), hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), battery electric vehicle (BEV), and fuel cell electric vehicle (FCEV)–in the future (2030) based on a WTW analysis for the present (2017) and an analysis of various energy policies that could affect future emissions. South Korea was selected as the target region because it has detailed energy policies related to alternative vehicles. The WTW analysis for the present was performed based on three sets of subordinate analyses: (1) life cycle analyses of eight base fuels; (2) life cycle analyses of electricity and hydrogen; and (3) analyses of the fuel economies of seven vehicle types. From the WTW analysis for the present, the national average WTW GHG emissions of ICEV-gasoline, ICEV-diesel, ICEV-liquefied petroleum gas, HEV, PHEV, BEV, and FCEV were calculated as 225, 233, 201, 159, 133, 109, and 55 g-CO2-eq./km, respectively. For calculating the WTW GHG emissions in the future, two policies regarding electricity production and three policies regarding hydrogen production were analysed. Three cases with varying the degrees of improvements in fuel economies were considered. Six future scenarios were constructed, and each scenario represented the case in which each energy policy is enacted. In the reference scenario, for compact car, the WTW GHG emissions of ICEVs-gasoline, HEV, PHEV, BEV-200 mile, FCEV were analysed as 161, 110, 97, 86, and 91 g-CO2-eq./km, respectively. The differences between ICEV/HEV and BEV were predicted to decrease in the future mainly due to larger improvements of ICEV/HEV in fuel economies compared to that of BEV. The future life cycle GHG emissions of electricity and hydrogen were calculated according to energy policy. Both two policies regarding power generation were confirmed to increase the benefits of utilizing BEVs, but current energy policy regarding hydrogen production were confirmed to decrease the benefits of utilizing FCEVs. Based on the comprehensive results of this study, a framework was proposed to evaluate the impacts of an energy policy regarding electricity and hydrogen production on the benefits of using BEVs and FCEVs compared to using HEVs and ICEVs. This framework can also be utilized in other countries when they assess and establish their energy policies.