Reducing Carbon Dioxide (CO2) emissions is one of the major challenges for automobile manufacturers. This is driven by environmental, consumer, and regulatory demands in all major regions worldwide. For conventional vehicles, a host of technologies have been applied that improve the overall efficiency of the vehicle. This reduces CO2 contributions by directly reducing the amount of energy consumed to power a vehicle. The hybrid electric vehicle (HEV) continues this trend.
However, there are limits to CO2 reduction due to improvements in efficiency alone. Other major improvements are realized when the CO2 content of the energy used to motivate vehicles is reduced.
With the introduction of Extended Range Electric Vehicles (E-REVs) and Plug-in HEVs (PHEVs), electric grid energy displaces petroleum. This enables the potential for significant CO2 reductions as the CO2 per unit of electrical energy is reduced over time with the improving mix of energy sources for the electrical grid. Vehicle electrification also introduces consumer choice in the CO2 content of the energy when electric power providers offer renewable power options for drivers.
To quantify the realizable reductions in transportation CO2 emissions, we consider several scenarios. We evaluate the CO2 reduction from the introduction of PHEVs and E-REVs onto the existing power grid. We consider the impact of consumer behavior and the availability of charging and the expected benefits based on vehicle operation. We evaluate the CO2 reductions possible due to a combination of changes in the power grid and in vehicle stock over time. Finally, we evaluate the impact of selective and voluntary consumer behaviors on CO2 contributions.