New data suggests that electric vehicles may not be an easy future substitute for the gasoline-powered fleet, as EVs currently travel less than half as much as the US fleet average.

A team from the University of Chicago, University of California, Davis, and UC Berkeley combined billions of hourly electricity meter measurements with address-level EV registration records in California—home to about half of the EVs in the United States. They found that the arrival of an EV in a household increases household electricity consumption by 2.9 kilowatt hours per day—less than half the amount assumed by state regulators.

Adjusted for the share of out-of-home charging, the electricity consumed translates to about 5,300 electric vehicle miles traveled (eVMT) per year—roughly half as large as EV driving estimates used by regulators and also half as large as vehicle miles traveled in gasoline-powered cars.

They reported their findings in a working paper published on the National Bureau of Economic Research (NBER) website.

There’s still so much we don’t know about the costs and benefits of EVs, so it seems appropriate to have some humility around this energy transition. Approaches that leave multiple technology pathways open are desirable; bans and mandates seem premature.

—co-author David Rapson, an associate professor at the UC Davis Economics Department

The takeaway here is not that EVs should never or will never be our future. It’s rather that policymakers may be underestimating the costs of going fully electric.

—co-author Fiona Burlig, an assistant professor at the University of Chicago Harris School of Public Policy

The research also studied different types of EVs and found that Teslas consume almost twice the amount of electricity per hour than the others studied. This is likely due to a combination of factors, including Tesla’s higher battery capacity.

Future research should seek to test a variety of potential explanations for the apparent low utilization of EVs. First, buyers of EVs to date may not represent the broader vehicle-owning population. Second, the marginal utility of eVMT may be lower than that of travel in conventional vehicles. This may be true for a variety of reasons, including an absence of sufficiently dense charging networks, range anxiety, or other attributes of the EV travel experience. Third, EVs may be complements to gasoline-powered vehicles, rather than substitutes for them. The vision of transportation electrification rests on EVs leading to a substitution of VMT away from conventional cars. If, instead, EVs are primarily owned by households with multiple cars, it will be important to understand why. Fourth, low eVMT may be a natural response to high electricity prices in California. While recent evidence suggests this may not be the case (Bushnell, Muehlegger, and Rapson (2021)), the influence of both electricity and gasoline prices on demand for and usage of EVs remains an area requiring further research. This paper demonstrates how pairing rich data on household-level electricity consumption with vehicle registration information can help answer these and other questions.

—Burlig et al.

Resources

• Fiona Burlig, James B. Bushnell, David S. Rapson & Catherine Wolfram (2021) “Low Energy: Estimating Electric Vehicle Electricity Use” NBER working paper 28451 doi: 10.3386/w28451