In a study done by the University of Michigan and Ford, they found that battery electric vehicles have approximately 64 percent lower “cradle to grave” lifecycle greenhouse emissions than their internal combustion engine counterparts.

With a focus on evaluating greenhouse gas emissions, researchers looked at three different model year 2020 powertrain options—internal-combustion-engine vehicles, hybrid-electric vehicles, and battery-electric vehicles—for midsize sedans, midsize SUVs, and full-size pickup trucks, accounting for differences in fuel economy, annual mileage, vehicle production, and vehicle lifetime across vehicle classes.

Researchers, for instance, found that switching an internal-combustion-engine vehicle to a battery-electric vehicle results in greater total tonnage of emissions reductions as the vehicle size increases, due to the greater fuel consumption of larger vehicles. Although the percentage savings is approximately the same across vehicle classes, on average replacing an internal-combustion-engine sedan with a battery-electric sedan saves 45 metric tons of carbon dioxide equivalent, replacing an internal-combustion-engine SUV with a battery-electric SUV saves 56 metric tons of carbon dioxide equivalent, and replacing an internal-combustion-engine pickup with a battery-electric pickup saves 74 metric tons carbon dioxide equivalent over the lifetime of the vehicles.

The researchers also found that battery-electric vehicles have larger greenhouse gas emissions in their manufacturing than internal-combustion-engine vehicles, due to battery production, but this impact is offset by savings in their operation. For battery-electric vehicles and internal-combustion-engine vehicles, the breakeven time is 1.2 to 1.3 years for sedans, 1.4 to 1.6 years for SUVs, and 1.3 years for pickup trucks, based on the average U.S. grid and vehicle miles traveled.

Of course, for electric vehicles, the emissions intensity of the local electricity grid is also an important factor. But researchers found that concerns about battery-electric vehicles having higher emissions than internal-combustion-engine vehicles or hybrids are largely unfounded, at least in the United States. And this is even assuming only modest progress towards power grid decarbonization.

Charging strategies can further reduce battery-electric vehicle greenhouse gas emissions. The study found that charging during the hours of the day with the lowest grid emissions intensity can reduce emissions by 11 percent on average. Furthermore, deployment of electric vehicles and expansion of renewable energy resources like solar and wind should be done at the same time as the benefit of each is increased by the development of the other.