Grid decarbonization significantly reduces the overall emissions of plug-in hybrid electric vehicles (PHEVs) by lowering the carbon intensity of the electricity used for charging. Since PHEVs rely partially on electric power, the emissions associated with their electricity consumption depend heavily on the electricity generation mix.
Impact of Grid Decarbonization on PHEV Emissions
- Lower Emissions from Electricity Use: As the power grid incorporates more low-carbon sources (such as renewables and nuclear) and reduces fossil fuel dependence, the emissions intensity of electricity generation declines. This directly decreases the well-to-tank emissions of PHEVs, which in turn lowers their total life cycle greenhouse gas emissions compared to internal combustion engine vehicles (ICEVs) or less electrified hybrids.
- Emissions Reduction Trends: According to the International Energy Agency’s Global EV Outlook 2024, PHEVs purchased in 2023 produce about 30% less lifetime emissions than ICE vehicles under current policies (STEPS scenario). This emissions gap increases to 35% for vehicles purchased in 2035 under a scenario with accelerated grid decarbonization (APS), largely due to cleaner electricity generation.
- Well-to-Tank Emissions Drop: Grid decarbonization leads to a 25-35% reduction in well-to-tank emissions for medium-sized electric vehicles purchased in 2023 and up to 55-75% reduction by 2035, due to a 50-65% drop in carbon intensity of electricity generation globally from 2023 to 2035.
- Regional Variability: The emissions impact of PHEVs varies regionally depending on the electricity generation mix. In areas with a high share of coal or other carbon-intensive fuels, PHEVs may have less emissions advantage or potentially increase emissions if charging adds to fossil generation. Conversely, in regions with cleaner grids, PHEVs demonstrate significantly better life cycle emissions performance than conventional vehicles.
- Charging Behavior and Timing Effects: The timing of PHEV charging can influence emissions, as charging during periods of lower-carbon electricity availability further enhances emissions benefits. Some studies suggest that charging flexibility and load-shifting to cleaner generation times can reduce emissions of nitrogen oxides (NOx) and improve overall emissions profiles, although results vary by grid and region.
Summary
Grid decarbonization is a critical factor in maximizing the climate benefits of PHEVs. As the electricity grid becomes cleaner, PHEVs’ overall emissions—both from fuel use and battery production—decline substantially, widening the emissions gap compared to conventional vehicles. This makes PHEVs increasingly effective as a transitional technology toward full electrification and reduced transport sector emissions. Without grid decarbonization, the advantage of PHEVs over gasoline vehicles is smaller, but still generally positive due to lower tailpipe emissions during electric operation.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-grid-decarbonization-impact-the-overall-emissions-of-phevs/
