This week the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) reported, based on a study from Argonne National Labs, that light-duty (i.e., passenger) plug-in electric vehicles last year saved Americans 44.8 trillion Btu, the equivalent of 470 million gallons of gasoline. Switching from gasoline to electricity also avoided 2.4 million metric tons of carbon dioxide pollution.
Probably of greater interest to consumers, EV drivers saved about $1.2 billion based on the $2.60/gallon nationwide average price of gasoline last year. And because a huge percentage of the nation’s EVs are in California, where gasoline averaged $3.72, actual savings were closer to $1.7 billion.
Benefits Expected to Improve Due to Longer All-Electric Ranges
These numbers are expected to improve in the years to come. The reason is that the electric driving range of the vehicles on the market during the past several years was, on average, lower than today’s electric driving range. And while vehicle performance is getting better, we’re also seeing more and more models gaining plug-in electric capabilities. This means that more vehicles will be able to drive at least a modest number of miles using electricity.
There will also be more fully electric vehicles on the road; even better, unlike during the study period when a fully electric vehicle’s range averaged less than 150 miles, today the base range is typically more than 200 miles and many vehicles offer ranges that exceed 300 miles. This is significant because, as shown in the table below, the Argonne report’s authors assumed lower-than-average annual driving for fully electric vehicles. Without that discount, the savings would have been even greater. As shown in the following table, once a vehicle’s electric driving range hits about 300 miles, it is assumed to be driven the same number of miles annually (about 13,500) as an internal combustion engine vehicle.
Of course EVs do need to fuel up, but using electricity to power a vehicle costs the equivalent of about $1/gallon, which is a big savings no matter where you are. Electric vehicles continue to save money because they require hardly any maintenance or servicing. And all that extra time saved from not going to the gas station and mechanic certainly has a value too.
Environmental Benefits: Good and Getting Better
Finally, driving with electricity is better for the environment because producing a kWh for driving creates less carbon dioxide (CO2) than using an equivalent amount of gasoline.
- Internal combustion engines: The amount of tailpipe emissions from an internal combustion engine vehicle can be found by multiplying the miles driven by the number of grams of CO2 per gallon of gasoline (8,887) and dividing by the fuel economy (in miles per gallon, or mpg).
- Electric vehicles: The emissions to drive an electric vehicle are found by multiplying the miles driven by the electricity consumption (in kWh per mile) by the emission rate. Deriving emissions from electricity isn’t as straightforward because the carbon content of electricity isn’t constant; rather, it is based on the fuel source (e.g., nuclear, coal, gas, wind, solar). According to the EPA, electricity production in the U.S. emitted an average of 430 grams of CO2 per kilowatt-hour in 2018.
Despite that variability in electricity, the benefits are overwhelming. A gasoline-powered vehicle consuming 30 mpg emits 300 g CO2 / mile, while a BEV consuming 0.33 kWh / mile in 2018 was responsible for 142 g CO2 / mile. The true savings is likely to be even greater, because so many EVs are charged in California and other states where electricity’s carbon intensity is lower than the national average,. Moreover, EV drivers are likely to have even cleaner energy due to home solar panels or through the voluntary purchase of clean energy from their utility.
All of the benefits described above are only getting better with time. While fully electric vehicles deliver the biggest benefits, even plug-in hybrids will also offer advantages such as electric driving for quick errands and stop-and-go traffic, both of which cause disproportionately more pollution per mile driven. Of course an important consideration for plug-in hybrids is whether drivers actually plug them in and enjoy the benefits, so public policy should strongly support home charging through efforts such as utility-funded outreach and education, as well as discounted or free chargers.
The bottom line is that the market is maturing, more manufacturers are offering plug-in options, and consumers are getting accustomed to driving electric. On the technology side, batteries are getting less expensive and becoming more efficient, which together will result in more miles of electric driving.