Impacts of EV adoption on household electricity use


The year began with the first major U.S. automaker, GM, pledging to go all electric by 2035. Their pledge came as powerbrokers around the world announce their intention to “go all in” on electric vehicles (EVs).  EVs have been anointed as the replacement technology, but currently comprise less than one percent of the vehicle fleet. Meeting these lofty goals without imposing serious costs on consumers will require EVs to offer the same services as gasoline cars currently provide. But is this the case so far?

One way to start to answer this question is to look at how much people are driving their EVs. If households are putting as many miles on their EVs as on their gas-guzzling counterparts, this is a good sign for the EV revolution. On the other hand, if households only drive their EVs sparingly, it might be an indication that current EV technology simply isn’t as good. That could signal more innovation will be needed before consumers will make that switch en masse, or else the switch away from gasoline could be more costly than we hope.

Harris Public Policy’s Fiona Burlig, along with her co-authors at UC-Davis and UC-Berkeley, provides the first at-scale estimates of “electric vehicle miles traveled” (eVMT) that represents the overall EV population in California. To do so, Burlig and her colleagues combine nearly 12 billion hours of electricity meter measurements with household-level EV registration records from 2014 to 2017 to estimate how much EV charging is occurring at home.

They find that when a household gets a new EV, electricity demand increases sharply, and that this increase remains quite stable more than 6 months after adoption. However, the increase they see is relatively small: only 2.9 kilowatt-hours (kWh) per day, or less than half the amount state regulators have assumed using data from dedicated-meter households. That translates into about 5,300 miles of electric-powered driving per year—roughly half as far as regulators’ estimates, and only half as far as people on average drive their gas-powered cars.

All told, this suggests that households may not yet view EVs as a good substitute for their gasoline-powered cars and that, unless there are major improvements in EV technology, regulators and policy-makers have more work to do to convince drivers to abandon their gasoline-powered cars for EVs.