Electricity: powering vehicles & reducing pollution
File(s)
Author(s)
Mehlig, Daniel
Type
Thesis
Abstract
There is growing promise that electric vehicles (EVs) may lead to a reduction in the pollution caused by road transport.
This thesis begins by assessing the current link between EVs and the electricity system; how EVs are charged. The emissions produced in power plants for charging EVs have significantly decreased over the past decade due to the decarbonation of the electricity system, reaching 41 g CO2, 27 mg NOx and 0.7 mg PM2.5 per kilometre in 2019. But as marginal demand is still met by natural gas power plants there is a small emission increase for NO¬x and CO2 of up to 25%, for new EVs entering the system. In 2020, the COVID-19 pandemic highlighted how additional decarbonisation of the electricity system should continue and will bring additional emission reductions for EVs in the future.
This thesis then looks to the future, illustrating a path towards a fully electric fleet and decarbonised electricity system. Emissions from road transport will approach net zero in the 2040s if the current government road transport and power generation targets are met. Under this scenario, air quality may significantly improve over the next decade with exposure to NOx and PM2.5 reducing by 6.7 µgm-3 and 0.5 µgm-3, respectively, but this is only marginally better than without EVs due to the improvements in conventional vehicles. Beyond 2030, a fleet of EVs with a decarbonised electricity system may further reduce NOx and PM2.5 exposure by 1.6 µgm-3 and 0.1 µgm-3 compared to a conventional fleet by 2050. The long-term barrier for improving air quality for EVs is now non-exhaust emissions where exposure to PM2.5 may remain at a significant level (0.4 µgm-3) until 2050. Non-exhaust emissions are highly uncertain and may increase in the future with heavier and cheaper to run EVs.
This thesis begins by assessing the current link between EVs and the electricity system; how EVs are charged. The emissions produced in power plants for charging EVs have significantly decreased over the past decade due to the decarbonation of the electricity system, reaching 41 g CO2, 27 mg NOx and 0.7 mg PM2.5 per kilometre in 2019. But as marginal demand is still met by natural gas power plants there is a small emission increase for NO¬x and CO2 of up to 25%, for new EVs entering the system. In 2020, the COVID-19 pandemic highlighted how additional decarbonisation of the electricity system should continue and will bring additional emission reductions for EVs in the future.
This thesis then looks to the future, illustrating a path towards a fully electric fleet and decarbonised electricity system. Emissions from road transport will approach net zero in the 2040s if the current government road transport and power generation targets are met. Under this scenario, air quality may significantly improve over the next decade with exposure to NOx and PM2.5 reducing by 6.7 µgm-3 and 0.5 µgm-3, respectively, but this is only marginally better than without EVs due to the improvements in conventional vehicles. Beyond 2030, a fleet of EVs with a decarbonised electricity system may further reduce NOx and PM2.5 exposure by 1.6 µgm-3 and 0.1 µgm-3 compared to a conventional fleet by 2050. The long-term barrier for improving air quality for EVs is now non-exhaust emissions where exposure to PM2.5 may remain at a significant level (0.4 µgm-3) until 2050. Non-exhaust emissions are highly uncertain and may increase in the future with heavier and cheaper to run EVs.
Version
Open Access
Date Issued
2022-04
Date Awarded
2022-08
Copyright Statement
Creative Commons Attribution Licence
License URL
Advisor
ApSimon, Helen
Staffell, Iain
Sponsor
Natural Environment Research Council (Great Britain)
Great Britain. Department for Transport
Grant Number
NE/S013350/1
Publisher Department
Centre for Environmental Policy
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)