Assessing well-to-wheel decarbonization pathways and carbon pricing for a mixed-powertrain ride-sourcing fleet

Area of Science:

• Transportation emissions analysis
• Electric mobility pathways
• Climate change mitigation strategies

Background:

• Decarbonization of ride-sourcing fleets, especially those with hybrid electric vehicles, is crucial but underexplored.
• Existing studies often overlook lifecycle emissions, focusing solely on tailpipe reductions.

Purpose of the Study:

• To assess well-to-wheel emissions and carbon pricing impacts for a regional ride-sourcing fleet.
• To evaluate decarbonization strategies under various electrification scenarios and grid conditions.

Main Methods:

• Policy-anchored scenario-simulation framework.
• Hybrid ARIMA-LSTM model for mileage demand forecasting.
• Integration of time-varying emission factors and national electrification pathways.

Main Results:

• Tank-to-wheel emissions reductions of 33%-100% are overestimated; actual well-to-wheel reductions range from 17%-44% with full electrification.
• Faster grid decarbonization significantly amplifies cumulative emission reductions.
• Fleet electrification acts as a financial hedge against carbon fees.

Conclusions:

• Vehicle electrification alone is insufficient for deep decarbonization; parallel grid decarbonization is essential for compounding benefits.
• Policymakers must align vehicle electrification mandates with grid decarbonization for realistic sustainability outcomes.
• Integrating transportation and energy policies is key for holistic long-term sustainability.