No matter where you live in the United States or what your driving habits are, a battery electric vehicle is likely to have a smaller carbon footprint and cost less overall than a comparable gasoline-powered vehicle, according to a new analysis.
The study calls into question some persistent myths about EVs – and gives policymakers and individual drivers tools to evaluate the benefits for their specific situation.
It’s well known that the emissions savings from EVs vary due to a number of factors, such as the greenness of the local electricity grid, climate, and a person’s driving habits. EVs also tend to cost more upfront than gasoline cars, but have lower fuel and maintenance costs. How all these tradeoffs pencil out can be hard to figure.
Most previous studies have looked at just one or a few of these factors at a time. In the new study, the researchers gathered data from every U.S. zip code and systematically analyzed a host of factors that might affect emissions or costs: local climate, electricity sources, congestion, urban versus rural driving and traffic patterns, electricity and gasoline prices, and individual variations in driving habits.
They used the results of the analysis to update a freely available website that compares the life-cycle emissions and total ownership costs of almost any type of EV and gasoline vehicle. “We provide quantitative answers to common questions asked by prospective EV owners,” the researchers write.
EVs reduce emissions the most in areas with a green electric grid, heavier traffic, greater annual travel distances, and mild climate, the researchers found.
In any given area, EVs reduce emissions more for those drivers who drive more often, drive bigger vehicles, and spend more time stuck in traffic.
In most parts of the country, an EV reduces greenhouse gas emissions by 40-60% compared to a gasoline car. Not surprisingly, the greenness of the local grid is the biggest factor in driving differences in emission savings from place to place.
Many members of the public assume that EVs are no better than gasoline cars if the electricity that powers them comes from fossil fuels. But grids have gotten greener, and even in areas with the most carbon-intensive electricity, EVs almost always come out ahead, the researchers found.
Moreover, because grids everywhere are getting even greener yet, this will become less of a source of variation in the future, and individual driving patterns will matter more and more. Already, in some instances individual differences in driving patterns can matter as much as all regional factors combined, the analysis shows.
EVs also reduce emissions even in the most unfavorable climate conditions, upending assumptions that they have little environmental benefit in cold climates. It’s true that battery function takes a hit in the cold, but considered over the course of a whole year the effect on emissions savings is pretty small.
The cost of electricity is the largest factor in determining the relative costs of the different types of vehicles. In most areas of the United States, EVs are cost-competitive with gasoline vehicles, even without tax credits for clean vehicles. In areas where electricity is relatively cheap, EVs tend to have a lower lifetime ownership cost than gasoline cars.
Source: Miotti M. and J.E. Trancik. “Determinants of electric vehicle emissions savings and costs across locations and individuals.” Environmental Research Letters 2026.
Image: ©Anthropocene Magazine.
