This DC Fast charging station in Grant’s Pass, OR has only 2 stations and only one car
Brad Templeton
There were a reported 60,000 EV charging stations at over 22,000 sites in the USA as of 2018, Impressively 15% are DC “fast” chargers and 87% of them are public. Yet there are claims that the vast majority of these see very light use — charging less than 10% of the time. While some, like Tesla superchargers and chargers at prime workplace parking lots see heavy use, many of them sit idle. The reason is they were designed for an already fading first era of electric vehicles.
That first era featured vehicles like the Nissan Leaf and many others that could go under 100 miles on a charge. These generated “range anxiety” and people sometimes needed a mid-day charge to get on with their travels, and they all wanted the knowledge they could get one if they needed one. (They actually don’t need one that often, since the average car drives only about 40 miles per day, but the fear is stronger than the need.)
The second era comes from cars with 200 miles of range or more, like the Teslas, and also the Chevy Bolt, latest Leaf, and a few others coming out soon. A 200 mile car has the range for pretty much all “local” driving, and only needs more on special long trips and road trips. This is why Tesla put a focus on their supercharging network, to make the latter possible.
Yet for the thousands of “level 2” chargers (offering 4 to 10kw of power) it seems a giant mistake has been made. Charging stations in the parking lots of shopping areas and restaurants have almost no value to the drivers of the second era of cars. And they weren’t that useful even to the shorter range cars — having to use one meant a major inconvenience.
Most charging is done in people’s homes. The other three places charging works are:
- At hotels (or other substitutes for your home.)
- At workplaces where people park all day, for those who can’t charge at home
- High speed charging for special long trips
To understand it, it may make sense to put it in the vocabulary of gasoline, though that’s usually the wrong way to look at it.
Imagine if everybody had a slow gas pump at home that cost $1/gallon for their 30mpg car. While it might only pump a gallon an hour, you just put in the nozzle when you come home and you’re always full in the morning.
In that world, it would be rare to use other slow gas stations around town — even when (as they frequently are) free! It’s not worth the inconvenience to park in their special slots, to pick up a gallon (dollar’s worth) at best. When it’s not free, it ranges from $2.50 to $5 per gallon, a price nobody would pay if they pay $1/gallon at home, except at the rare times they are desperate.
Tesla seems smarter about getting high utilization at their charging stations — but the slow chargers here are free and convenient
Brad Templeton
On long trips, you would make use of the gas stations on major routes. Even though they cost $2/gallon and take anywhere from 40 minutes to an hour to fill, you would use them because there is no other choice.
On the other hand, if your hotel gives free gas to guests (as a small but growing set of hotels do) you would be keen to take that, and would even probably pay up to about $2.50/gallon to avoid the wait and $2/gallon cost at the highway stations.
Workplace charging is of more mixed value. For those who “fill up” at home, it may not be worth charging at work if it involves any inconvenience. However, a large fraction of employees offer it free, and even give premium parking spaces, which is attractive. Workplace charging is also the only choice for people who don’t have any way to do it at home, because they park on the street or in apartment parking lots with no charging.
Robocar charging
As places build out charging infrastructure, they should keep these second era concepts in mind. But they should also consider the even more important third era — that of cars which can travel to charging on their own. These need not be full robocars that can safely carry people down a busy street. They might only be capable of low speed trips over short distances, and possibly only in super light traffic such as at night. This is a much easier problem than a general robocar. Indeed, while many doubt whether Tesla can deliver that full robocar as promised it is much more probable that they might deliver a car that can drive to a charging station.
At a charging station, the car must still plug in. One simple solution, already planned by some charging companies, is to have “full service” stations, with an attendant. This attendant’s job is actually too easy unless the station has many stalls, so you may want them to perform other tasks, like doing car washes, or security, or even outside online work, to keep the costs low.
Eventually we will also see automatic plug in. This turns out to be easier when you think, because if the car is a robot it can position itself with great precision. That means the charging plug need only be on a fairly simple plunger arm that can push the plug in and out, as long as the charging door can open itself, as is the case on Teslas. Sadly, because cars all put their charge ports in different locations, supporting lots of car models in this way is challenging.
Another option is a “park and wait” approach for use in lots that see occasional human traffic, including humans coming to manually charge their own cars. In this case, you can set up a “gig work” approach, where the humans who happen to enter the lot see a sign saying, “Earn quick and easy money. Plug or unplug the 4 cars waiting here and earn $2.50 through our app.” Obviously,
the wait is unpredictable, but robots don’t mind waiting. If the reward got high, then people driving Uber or otherwise going past the lot might get an alert and detour into the lot to make some quick money.
While this is hardly a common situation, there happen to be two large lots, one with 70 chargers and the other with 20 which are a short and easy drive from my home. In the near future, they could work this way.
Robocar charging lots will be large, and may do double duty as parking and manual charging during the day. They can be located very close to power stations, to make it easy to bring in all the megawatts needed. Once these arrive, people no longer need to install charging in their homes. Home charging can be simple and cheap to install, but more often than you would hope it is very expensive because it requires an upgrade of the house’s main electrical service, costing $4,000 or more. When cars can creep away from homes and hotels to robotic charging lots, there is no longer the same need to build lots of charging infrastructure.
Those wishing to build charging infrastructure in the places that don’t get used much, like shopping centers, should plan for a future where the charger becomes useful as a night charger for robots, either because there is a human worker present at night, or they leave a place to install a simplified robot arm charger.
