Developments in the EV space - some second order thinking
We’re all going to be charging soon
[This post originally published elsewhere on 2024-09-21]
Now that we're past the first hurdles in the EV space, we can move on to second-order thinking. The fact of EV viability has been established. The fact of EV superiority has been established. EV adoption has begun in earnest.
Having established that we are moving to EVs, and that we're moving at a reasonably predictable rate, we can now project second order effects, to wit, the changes that are coming as a result of the changes that are coming. (cf Second derivative being the rate of change of the rate of change).
I note with interest a recent discussion about airport parking lot EV charging, with observers reporting the presence of L2 and L1 charging facilities at various airports. We'll develop that discussion shortly, but tangentially, Rivian's design decision placing the charging port on the rear passenger corner of their upcoming R2 is provocative. Their rationale is that curbside charging is coming, and the Tesla-style driver-side-rear charging port no longer makes sense. I concur — we must assume that EVs will be routinely plugged in to 110V-US/240V-EU outlets — at shopping centers, on streets, in parking garages and naturellement, in private drives and home garages.
The mix of L2 and L1 facilities at airports has provided some interesting feedback from people who have used them. L2 seemingly makes sense, because faster is always better, right? Well, sure, if you need a lot of charge in a short space of time. That's a classic road trip use case -- drive, drive, drive, charge, charge, charge, drive, drive, drive. Airport parking is entirely different — drive, park, travel for multiple days, return, drive. Except when it's cold and the car needs to keep the battery pack warm.
Por Quoi, L2?
L2 chargers aren’t that expensive, and they’re useful for overnight charging — you’ll get to the customary 80% charge in about four or five hours assuming an outlet delivering something in the range of 40 Amps. This is the use case for home charging. You plug in when you get home, set the car to begin charging when the cheap electricity rate kicks in (you’re on a TOU [1] plan, right?) and by the the time you’re done brewing your morning coffee, the chariot is ready to go, and of course, pre-warmed in winter or pre-cooled in summer. This is the sweet spot of L2.
L2 at the airport doesn’t make that much sense. L2 pulls 40A for a couple of hours. For a car that’s going to sit at least a couple of days, unless the L2 chargers throttle the charge rate such that they reach 80% just in time for the owner’s return, which is a more complex problem. A much better charging use case for the airport (at least in long term parking) is L1, a nice slow charge that gives you twenty or thirty miles of range a day. For electric utilities, this is ideal — a slow steady draw, evened out across an entire car park of cars. You’re given a smooth, steady draw of power that a power company can easily service — that’s easy money.
Solutions to the airport L2 charger problem
De-rate the L2 chargers
Provide controllable power draw that matches target charge to the anticipated return of the car owner
Switch to L1, giving a very favorable draw profile for the entire parking lot
Places that should have L2
Movies
Shopping centers
Restaurants
Gyms and Sports facilities
Places that should have L1
Long-stay anything
Short-stay, high return anything (e.g. corporate parking lot where employees park all day, every day) where there’s a fixed pattern of arrival
As much as I dislike referencing Twitter, this is the post that prompted these thoughts.
[1] Time of Use.