SCANDAL: EVs have a dirty little secret!

Juliet writes*

Policymakers and pro-climate groups want to address the climate crisis by replacing cars with internal combustion engines (ICEs) with electric vehicles (EVs). But can EVs be a true substitute for ICEs? Perhaps not. To fully grasp the potential benefits of EVs, it is important to know the extent to which EV owners actually end up driving them. This presents a challenge. Because EVs are primarily charged within homes, the existing charging data has been limited.

A 2020 study from the University of California – Davis [pdf] estimated that Californians drive their battery EVs 11,35o miles per year on average. These past analyses, however, were based on surveys and small sample sizes. Surveys are often inaccurate due to response bias, meaning that people have a tendency to respond to surveys with answers they believe to be more socially acceptable than true. This can be a subconscious phenomenon which skews the data. Small sample sizes can similarly affect data because a small subgroup may be unrepresentative of overall EV owners.

This year, another study at multiple universities including the University of California – Davis [pdf], using a much larger sample and direct measurements, indicates that EVs are being driven significantly fewer miles than their ICE counterparts. The study utilizes billions of California electricity meter measurements merged with address-level data about EV registrations in order to estimate the change in energy usage from EV charging. The result is an unexpectedly low change — a 2.9 kWh daily increase in electricity usage — signaling lower EV usage than previously thought. After adjusting for charging outside of the home, those results translate into battery EVs being driven only 6,700 miles per year. Data from the California Department of Public Health indicates that Californians as a whole typically drive around 9,000 miles annually.

The explanation for the low usage of EVs is not exactly clear, but the paper [pdf] cites a few possibilities. One possible explanation is that EVs might provide lower marginal utility per mile traveled when compared to ICE miles. The lower utility could stem from shorter distance range of EVs or insufficient charging networks. Another reason for less than expected charging could be that most EVs are owned by multiple-vehicle households. This would mean that EVs are a complement to ICEs instead of a substitute, and households who buy an EVschoose to drive their ICE more often than their EV. The last explanation I will touch on is that low charging rates could be a reflection of high electricity prices in California.

No matter the explanation, this information has important implications for future climate policy. The results indicate that policymakers should maybe reconsider making drastic commitments to EV technology in order to reach their decarbonization goals because it may not be as effective as it seems.

Bottom Line: EVs might not replace conventional gas-powered vehicles, so  policymakers might need to pump the brakes on EV promotion until they have better information and instead focus on other ways to  decarbonize society.


* Please help my Environmental Economics students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice :).

Author: David Zetland

I'm a political-economist from California who now lives in Amsterdam.

3 thoughts on “SCANDAL: EVs have a dirty little secret!”

  1. This is a well-written post on a very interesting topic Juliet! If I would guess I’d say that the low mileage in EVs may be because of the higher uncertainty in driving them longer distances because it may be more difficult to find a charging station along the way. This may especially be true for families with several cars so they use one for long distances and one for shorter distances. So perhaps you could look into the concentration of charging stations within your study area. I would also look into what subsidies there are for owning an electric car. In Sweden, it is popular to own a hybrid car because it is subsidized as an EV but most people drive it on conventional gas anyways. Especially so outside of cities where possibilities to charge are close non-existent. Hence, why more people buy hybrids than EVs. This may be outside the scope of your research but I would also be interested in hearing more about the materials used in the EV batteries and how environmentally and socially beneficial those really are. I hope these thoughts will help you when going forward and I look forward to reading more about this!

  2. This is a very good post, I really enjoyed reading it! The title caught my attention and throughout the post you kept me engaged, with some clear explanations of the trend as well as examples of how methodology is important when considering questions of environmental economics. I think that it particularly important to consider not only what drives the use of EV, but also why ICE’s are preferred (or maintained) in consumer’s everyday driving behaviour. Also, other modes of transport should be considered. EVs can also be used less as people decide more to go for substitute modes of transport such as a walk/bike ride/public transport, even though this is something that is probably not as frequently done in the US/California as in other parts of the world (The Netherlands/Europe). It can, however, be something that explain why EVs are not used as frequently, as other (maybe even more sustainable) transport ways are also on the rise, and (sustainable-focused) people hence might rather opt for that.

  3. Super interesting post and observation Juliet! It may be indeed that EV charging stations are not as widely available as gas stations, and therefore driving an EV (long distance) could be less attractive. It could also, maybe, be a “status” thing. In some circles (like LUC) being ‘green’ is seen as cool and hip, while in others this may differ and be more of a ‘vroom vroom is cool’ kind of hype (and many EV’s are near to silent). I do not know anything about Californians but I do know that many people (in general) go out of their way to be part of particular circles. Moreover, I wonder whether there is a price difference in buying an EV or an ICE? Maybe there is also a financial reason for certain groups (potentially the group that drives above averagely far a year) to not shift. Also, as a car is a pretty big investment, maybe it is just a gradual change before the majority of society shifts to EV’s.
    All the hypotheses above could indeed be solved with your suggestion of EV policy to be changed to make EV’s more attractive.
    One thing that may also be interesting to look at is the emission of the production of EV’s (compared to ICE’s, is there a clear difference?) and to see where most conventional electricity comes from… many electric (thus portrayed as green) products actually run on electricity made from fossil fuels. (https://www.carbonbrief.org/factcheck-how-electric-vehicles-help-to-tackle-climate-change)

Leave a Reply

Your email address will not be published.