Influence of Electricity Generation Emissions Intensity on PHEV Lifecycle Emissions
- Zero Tailpipe Emissions, Emissions Shifted to Electricity Production
PHEVs running on electricity produce zero tailpipe emissions, but the overall emissions depend on how the electricity is generated. If the grid relies heavily on fossil fuels like coal or natural gas, the PHEV’s lifecycle emissions increase due to the carbon intensity of the electricity used to charge its battery. - Lifecycle Emissions Reductions Depend on Grid Decarbonization
According to the International Energy Agency (IEA), PHEVs purchased in 2023 produce about 30% less emissions than internal combustion engine vehicles (ICEVs) on a lifecycle basis under the current electricity mix scenario. This reduction improves to around 35% for PHEVs purchased in 2035 with further decarbonization of electricity generation. Thus, cleaner grids directly enhance the emissions benefits of PHEVs. - Utility Factor and Real-World Usage Patterns Affect Emissions
The actual emissions savings also hinge on the “utility factor” — the share of kilometers PHEVs travel using electric power versus gasoline. While official ratings often assume 40-65% electric driving, real-world utility factors tend to be lower, which diminishes emissions benefits. Higher grid emissions intensity combined with low electric driving reduces the lifecycle emission advantage of PHEVs. - Grid Mix Variability and Charging Patterns are Critical
Studies show considerable variation in emissions depending on when and where PHEVs are charged. Grids with lower carbon intensity reduce emissions associated with electric miles more effectively. The timing of charging (off-peak vs. peak hours) and the local fuel mix (e.g., hydro-heavy Quebec vs. coal-heavy regions) shape the lifecycle emission outcomes. - Quantitative Emissions Comparison
For PHEVs, the embedded emissions from gasoline use (non-electric miles) are about 0.29 lb CO2 per mile, while emissions from electricity generation depend strongly on grid carbon intensity. The combined emissions profile is a weighted sum of emissions from electric and gasoline driving modes, reflecting the vehicle’s charge-depleting (electric) and charge-sustaining (gasoline) operation modes.
Summary
The emissions intensity of electricity generation affects PHEV lifecycle emissions by determining how “clean” the electric miles are. Lower carbon intensity grids lead to greater emission reductions by enabling more effective use of the electric mode. Conversely, high carbon intensity electricity diminishes the benefits of PHEVs, especially if the vehicles are not charged frequently or driven predominantly in gasoline mode. Increasing PHEV utility factors—more electric driving enabled by cleaner grids—optimizes lifecycle emission savings.
In essence, the cleaner the electricity generation, the more lifecycle emission benefits PHEVs provide compared to conventional vehicles.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-emissions-intensity-of-electricity-generation-affect-the-lifecycle-emissions-of-phevs/
