Electric vehicles need to lighten up. Literally.
(Today’s blog is co-authored by Blake Shaffer, who is an Assistant Professor at the University of Calgary.)
Let’s get something straight, again. If we want any chance in hell of getting to net zero, we need to electrify the vast majority of end uses and decarbonize the grid. Electric vehicles (EVs) have a big role to play here.
But EVs are still – vehicles. Warts and all. And as three bald guys (the two of us and Costa Samaras of Carnegie Mellon) point out in Nature this week: they are heavy. And heavy vehicles come with costs. So let’s recap and expand a bit on the points we make in the piece.
When Garth Brooks rides his future electrified Ford F-150 Lightning around downtown Nashville, with his battery in low places, he is bringing along 6500 pounds of steel, battery and perceived toughness. We are into comparisons. That is the equivalent of two Toyota Camrys. Or a regular internal combustion engine powered F-150 plus 1550 pounds of battery and support weight. That is the weight of an American Bison or a Holstein Cow. As Mike Anderson and Max pointed out many moons ago, heavier vehicles impose an externality on other traffic participants. Garth is safer, but everyone else is less safe if they get hit by a much heavier car than if Garth had bought the regular F-150. This is a classic externality story.
In our piece we compare that externality from additional weight, as measured by lives lost, to the climate benefits from driving the F-150 Lightning, considering both the current and future grid carbon intensity. The figure below shows what we found. The Y-Axis measures the social cost of the F-150 lightening’s additional weight and its climate benefits, if it were plugged into different (current and some future) grids across the world (as shown on the X-axis). The weight externality does not vary by how dirty your grid is, but the climate externality does.
If you are into nerdy calculations, we use the increased probability of death from getting hit by a heavier vehicle, combined with the probability of being involved in an accident and the differential in weight to calculate a weight external cost per mile, which assumes average miles driven for …….