Electric vehicles do not produce tailpipe emissions, but there are other factors to consider when assessing their environmental impact. Manufacturing is a big job, as well as where their power comes from. This is often used as an argument by opponents against the environmental benefits of EVs, but a new study confirms that, yes, a car that doesn’t spew pollutants when driven is indeed a lower-emissions option.
The study was published in May environmental research paper magazine. The key point is that EVs can reduce emissions by 40-60% compared to internal-combustion vehicles “in most places”. However, the exact amount of emissions reductions depends on a number of factors, the most important being the structure of the local grid where they are being operated. Coal-fired power plants increase the effective emissions of EVs charged by the electricity they produce, but the opposite is also true for renewable alternatives.
“The electricity mix is the most important contributor to these regional variations,” the study’s abstract reads, “with more uniform and greater emissions reductions occurring if the electricity supply were decarbonized.”
The Union of Concerned Scientists has been saying the same thing for more than a decade. It’s tracking real-world EV emissions in the US since the beginning of the modern EV era, showing how they’ve fallen as the grid gets cleaner. Right now, according to UCS, the average EV in the US has emissions equivalent to a 96-mpg gasoline car. the organization has a online tools This lets you see estimated emissions for a given year, make, and model in your zip code—useful for any potential EV purchase.
According to this new study, driving patterns also have a big impact. The researchers found that urban driving was better than rural driving for maximum emissions reductions. In frequent urban driving, plug-in hybrids can apparently achieve 80-90% of the emissions savings of all-electric vehicles, assuming they are charged regularly and operated in electric mode. In rural areas it has come down to 60%.
This would mean that, assuming high mileage and a lot of urban driving, local governments or fleet operators looking to reduce emissions only need to adopt 9% EVs for a 10% emissions reduction. Fleets with lower annual mileage but more rural driving would need to adopt 42% EV to achieve the same level of emissions savings. According to the study, local climate “has a more moderate impact” on relative emissions, as opposed to power mix and driving patterns.
There won’t be any reduction in emissions if people don’t buy EVs, and on that front, the study has some good news. EVs are cost-competitive with internal combustion “in many places and for many people,” the researchers said, with the main factor being the cost of electricity compared to gas prices. The advent of less expensive EVs like the Slate pickup and its Ford rival should make the cost picture even better for at least some buyers.
