The impact of plug-in hybrid electric vehicles (PHEVs) on emissions varies significantly by geographical region due to differences in the electricity generation mix that supplies their charging.
Regional Variation in Emissions Impact of PHEVs
- Coal-Dependent Regions (e.g., U.S. Midwest):
In regions where electricity is primarily generated from coal, such as the U.S. Midwest, introducing PHEVs can reduce CO2 emission intensity (measured as tons of CO2 per megawatt-hour). This is because PHEVs reduce reliance on petroleum for driving and the coal-based electricity grid can still emit less CO2 per mile driven by PHEVs compared to internal combustion engine vehicles. As a result, PHEVs in these areas tend to lower overall carbon emissions. - Regions with Clean Generation (e.g., areas with hydro and renewables):
Conversely, in regions with substantial clean electricity generation — for example, those relying heavily on hydroelectric or renewable sources — adding the load of PHEVs may actually increase CO2 emissions intensity. This occurs because increased electricity demand may be met by less clean, fossil-fuel generators rather than the existing very low-emission resources, thereby raising the carbon footprint associated with PHEV charging in these areas. - Variation in Vehicle Use and Market Share:
There are also geographic differences in the prevalence of PHEVs versus all-electric vehicles (BEVs). PHEVs have historically been more common in northern U.S. states, which influences the total electricity consumption and emissions patterns since PHEVs have higher electricity consumption rates and shorter electric ranges relative to BEVs. - Charging Time Effects:
The timing of PHEV battery charging influences emissions and cost impacts. Charging during the day may result in higher emissions and costs compared to nighttime charging, which often coincides with cleaner or cheaper electricity generation.
Summary
PHEVs tend to have a greater positive impact on reducing emissions in regions dominated by coal-fired power generation because the shift from gasoline to electricity reduces CO2 per mile. In contrast, in regions with cleaner electricity mixes, PHEV charging can paradoxically increase emissions if the additional electricity demand is met by fossil fuel plants. This regional dependency is critical for policymakers considering PHEV deployment strategies and the timing of charging incentives to maximize emissions benefits.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/are-there-specific-regions-where-phevs-have-a-greater-impact-on-emissions/
