Well-to-wheel GHG emissions and mitigation potential from light-duty vehicles in Macau

PurposeThe rapid growth of vehicle sales and usage has highlighted the need for greenhouse gas (GHG) emission reduction in Macau, a special administrative region (SAR) of China. As the most primary vehicle type, light-duty vehicles (LDV, including light-duty gasoline vehicles (LDGVs) and light-duty diesel vehicles (LDDVs)) play a key role in promoting the GHG reduction and development of green transportation system in Macau.MethodsThis study, on the basis of real-world tested and statistical data, firstly performed a streamlined life-cycle assessment (SLCA) on LDVs, to evaluate the potential GHG emissions and reduction through shifting to hybrid electric vehicles (HEVs) and electric vehicles (EVs).Results and discussionThe results show that the mean GHG emissions from the LDGVs, LDDVs, and HEVs per 100km were 25.16, 20.30, and 15.00kg CO2 eq, respectively. Under the current electricity mix in Macau, EVs with the emissions of 12.39kg CO2 eq/100km can achieve a significant GHG emission reduction of LDVs in Macau. The total GHG emissions from LDVs increased from 124.99 to 247.82 thousand metric tons over the periods 2001-2014, with a 5.42% annual growth rate. A scenario analysis indicated that the development of HEVs and EVsespecially EVshas the potential to control the GHG emissions from LDVs. Under the electricity mix of natural gas (NG) and solar energy (SE), the GHG emissions from EVs would drop by about 22 and 28%, respectively, by 2030.ConclusionsThis study develops a useful approach to evaluate the potential GHG emissions and its reduction strategies in Macau. All the obtained results could be useful for decision makers, providing robust support for drawing up an appropriate plan for improving green transportation systems in Macau.