Science Inventory

Evaluating long-term emission impacts of large-scale electric vehicle deployment in the US using a human-Earth systems model

Citation:

Ou, Y., N. Kittner, S. Babaee, S. Smith, Chris Nolte, AND Dan Loughlin. Evaluating long-term emission impacts of large-scale electric vehicle deployment in the US using a human-Earth systems model. Applied Energy. Elsevier B.V., Amsterdam, Netherlands, 300:117364, (2021). https://doi.org/10.1016/j.apenergy.2021.117364

Impact/Purpose:

Historically, electric vehicles (EVs) have had only a very small share of the passenger vehicle market. A variety of factors may result in much greater EV market shares in the future, including rapidly decreasing battery costs, increasing range, expanding charging infrastructure, performance and maintenance advantages, and the adoption of environmental and energy policies that promote EVs. If a much greater EV market share is to be realized, it is important that society understand the environmental benefits and disbenefits. Greenhouse gas and air pollutant emissions would be affected by EV market penetration, but understanding the net impact on these emissions is complicated. For example, such an analysis must account for the emissions from conventional vehicles that are being offset, an increase in emissions from the electric sector, changes in refinery emissions as demand for liquid fuels decreases, and any price-induced fuel switching in transportation and other sectors. Furthermore, policies and other factors may shape the evolution of the electric sector, and in particular, how it responds to increased electricity demands from EVs. We present and apply a modeling framework based on the Global Change Assessment Model (GCAM) to examine the net CO2 and air pollutant impacts of widespread EV market penetration through 2050. While providing an analysis of emission impacts, we also highlight important limitations of the analysis and research needs.

Description:

While large-scale adoption of electric vehicles (EVs) globally would reduce carbon dioxide (CO2) and traditional air pollutant emissions from the transportation sector, emissions from the electric sector, refineries, and potentially other sources would change in response. Here, a multi-sector human-Earth systems model is used to evaluate the net long-term emission implications of large-scale EV adoption in the US over widely differing pathways of the evolution of the electric sector. Our results indicate that high EV adoption would decrease net CO2 emissions through 2050, even for a scenario where all electric sector capacity additions through 2050 are fossil fuel technologies. Greater net CO2 reductions would be realized for scenarios that emphasize renewables or decarbonization of electricity production. Net air pollutant emission changes in 2050 are relatively small compared to expected overall decreases from recent levels to 2050. States participating in the Regional Greenhouse Gas Initiative experience greater CO2 and air pollutant reductions on a percentage basis. These results suggest that coordinated, multi-sector planning can greatly enhance the climate and environmental benefits of EVs. Additional factors are identified that influence the net emission impacts of EVs, including the retirement of coal capacity, refinery operations under reduced gasoline demands, and price-induced fuel switching in residential heating and in the industrial sector.