As the world moves away from fossil fuel to electric vehicles, billions of dollars are being invested, spent or planned to put in more EV charging. Recently the White House unveiled a $5B plan to put chargers every 50 miles. Much grander plans have also been touted, and EV charging startups are hot investment tickets. Even so, there’s a lot of misunderstanding of what sort of chargers solve the problem and when rather than where they are used.
You may wish to watch the video version of this article, which includes many useful images and videos to illustrate the points:
Much of this planing continues “gasoline thinking,” which is imagining that EVs are similar to gasoline cars that you drive around for a while, then fill up when you see the tank is low. Gasoline drivers are afraid of electric cars because they know they take longer to charge, and they don’t easily get away from their gasoline thinking.
To understand charging, and where to put it, it’s important to realize that it’s not so much about where you charge but when you charge, and more to the point, what you do while you are charging. That dictates the “where.” While people dream about 5 minute fast charges that parallel the gasoline experience, that probably won’t be the norm even when it becomes technically possible. Instead, one must understand the ideal activities to do while filling your electric car. In order, these are:
- Not even being aware it’s charging
- Sleep
- Sleep
- Sleep
- Did I mention sleep?
- Work
- Work
- Hang around the house
- Grocery shopping
- Other shopping
- Lunch
- Late evening (after 9pm) entertainment
- Other short breaks (ie. bathroom)
- Dinner
- Anything else
- Waiting for the car to charge
One of the key hallmarks of gasoline thinking is to think of energy as a commodity product, rather than seeing charging as a service. The wholesale cost of electrical energy (often as low as 2 cents/kwh) is a small fraction of the price paid by consumers, which depends much more on the where, when and how of charging. That retail price ranges from free to as much as 55 cents/kwh — nothing like gasoline. In fact, public charging should not be thought of as selling electricity.
Slow vs. Fast
What you do while charging is tied with how fast the charging is. Slow and Fast charging each have upsides and downsides:
- Slow charging equipment and wiring is much cheaper per station and safer. Fast charging usually requires major new electrical service installation. Because of the higher costs, fast chargers usually charge a lot more per unit of electrical energy – as much as 5 times the price at home in extreme cases.
- Fast chargers recharge more cars per day, and of course they do it faster.
- Fast charging causes more battery degradation. If you have the time, you prefer to charge slow.
- All cars can use the J1772 slow charging standard. Fast charging tends to be either Tesla or CCS in the USA, and more rarely CHAdeMO. Most Teslas will soon take CCS with a low-cost adapter.
- Really show charging, either Level 1 (1.5kw) or even 3kw actually meets the needs of the vast bulk of drivers if at home/work and it’s a lot cheaper to put in.
The upshot is that fast charging is primarily for road trips, special high-use weeks and, as a temporary stopgap, for people who can’t charge any other way.
While you sleep
Today, all factors clearly make sleeping the clear winner. Power demand is lowest at night and power is cheapest. And of course it takes no time from your day. In addition, the charging can be slow, which means it is done without needing expensive equipment or dangerous high-power circuits. It causes less damage to the battery. There’s only one thing not to love, namely the inability to use direct solar power (discussed below.)
Curbside charging is need for those who don’t have driveways and can’t charge at work, but not a lot … [+]
EVs work best for people who can charge when they sleep, at home or at hotels. As such, any incentives should focus on places where people park at night, including homes, apartment parking lots, and even curbside in places where people have no home parking spaces. In fact, if this is done, the only other charging you need is on road trips. Typically, around 3kw will handle almost all daily needs for 1 car, as the typical car needs only about 10khw per day on average. This sort of charging is low cost and easy to put everywhere.
While curbside charging should be rare, some new designs feature chargers which hang on power and light poles, if there is enough electricity there. A charging cord can be lowered to the street, commanded by the app or card which pays for charging. This is good because it does not require the very expensive step of digging up streets or parking lots.
Work
This company garage has 72 chargers, which is a lot until you realize it’s at Apple HQ. In the … [+]
Where you work (or park for your commute) is another great place. People usually park for 8 hours, allowing slow charging with low-cost equipment. There are a few downsides compared to the home, though. People do sometimes want their cars during the work-day. You only want to charge until about 3pm when power gets expensive, so you have fewer hours than overnight and most of all, you don’t park there on most weekends. This both creates an issue for heavy-driving weekends and also with the fact people arrive on Monday needing more charge than the other weekdays, and you want to handle that.
A “downside” is that many employers would rather put in fewer, slightly faster (like 7kw stations where the average car needs only 90 minutes) which forces staff to come out and move their cars regularly, to some inconvenience.
The big upside for work charging is that in time, the grid is going to move to be more solar. To make use of that, cars should charge in the day, from 8am to 3pm, which is naturally matched with work hours.
For those who work at home, or otherwise hang around the house (for example, doing childcare) you can get the best result, with charging while the sun shines in low cost home charging spots.
Not only will daytime power become cheap as the amount of solar grows, it turns out cars are the best place to send extra solar and renewable power. If you don’t store extra solar power, it’s thrown away. Better to sell it cheap to cars.
Shopping
This fast charger is at a grocery store. That’s an ideal location – people visit them regularly, … [+]
It’s actually likely we can put in slow charging for most people at home or work. We don’t have it yet, so there’s interest in other places. For that you need fast charging, 50kw or higher. This can mean either charging sessions of 15 minutes for those who charge almost daily, or 30-60 minutes for people who charge twice a week. As such, you want places that people go very frequently for short stops of these durations, and grocery shopping is the obvious match as almost everybody does it and does it frequently. Any type of shopping or service visits will do, of course, but most are not done as regularly.
When it comes to charging, you actually want the charging rate to closely match the amount of time needed for the errand. If fast charging is too fast, and the chargers are in short supply (which they are, because they are expensive) that means you may force people to cut short their errands, or come out in the middle of them to move the car, which can be highly inconvenient. The right answer might be a mix of expensive, very fast stations used by those stopping for just a short time, and medium speed for those planning longer stops.
Lunch vs. Dinner
Tritium and Chargenet imagine a Taco Bell with charging stations. The duration of a fast food diner … [+]
Meals are a great time to charge, and in fact are a major time for road-trip charging today. The problem is that this is limited to mealtimes. People will even eat outside of normal mealtimes because roadtrip charging is not optional, and almost everybody eats out on roadtrips as well. Lunch is the obvious time, particularly when people are charging at hotels where they sleep. Most road trippers don’t want to travel more than about 500 miles in a day, so an overnight charge combined with a late-lunch charge works well to allow charging to take zero time out of your day.
The problem, of course, is that everybody wants to charge at roughly the same time for meals. It’s very expensive to build charging infrastructure that is used just at lunch. Road trip meals tend to range from fast food (25 minutes) to sit-down (40 to 60 minutes.) Most sit-down meals take longer than a typical fast charge, so you actually prefer slower charging. It’s very annoying to have to get up in the middle of a meal to move a car.
Dinner is a different story. It’s very convenient, but electricity costs 2-3 times as much at dinner than at lunch or overnight. It’s better to eat at any restaurant you wish and then be able to charge while sleeping at hotels. Indeed right now, one of the problems with dining while charging is that many chargers are located only with fairly mediocre dining choices — chain fast food — but the appeal of charging while dining is so great that they will get used. Aside from locating charging with better restaurants, there are other options, like having eating spaces at the chargers (small rooms with tables) and having food delivered, or getting take-out on the way to the charger.
Dinner restaurants might consider having solar panels and batteries to get the power for lunch and diner without grid peak prices.
Other breaks and fleets
Breaks that are too short for a full charge can still be used by city dwellers who can’t charge at home or work. They can make do with short 10 minute charges a few times a week at places where they make quick stops. Short charges are no good for road-trippers who need full chargers, or city dwellers who want to charge only once a week. At least for the next decade, we will have a number of people who can’t get a charging space at home or work, but that number should dwindle.
Volvo recently announced a tiny partnership to put chargers at 15 Starbucks. (It was not clear if all the Starbucks were actually on the same corner.) You can’t fully charge in the time it takes to get a coffee, but if you do this at least every other day, it could be a reasonable plan. Again, people prefer coffee in the morning or early afternoon over coffee at night.
Fleets present a different issue. Some fleet cars, including taxi/Uber
Waiting while charging
Concept of fancy future charging station, with lounge, of Electrify America
With gasoline, the norm is to simply wait while the car is filling up, usually holding the nozzle. At some stations you can go in to shop or use the toilet, but this is not usually done while pumping. Since it only takes about 4 minutes, we don’t mind a lot. Waiting for 10 minutes to an hour is an entirely different story. While many companies tout that they can do a “10%to 80% charge” in a very short time, or will in the future, that short time is usually in the 10 minute range. Charging in 5-10 minutes might be doable but it’s always going to require expensive, super-high-wattage equipment. It’s probably not going to be good on batteries, so even if you can do it, you probably will only do it when you really need it — like on hard-pushing road trip where you haven’t got time for more than a bathroom pit stop. It’s unlikely to be the norm.
There is one modern alternative to waiting, though. Today, almost all of us spend lots of time online, either for work or fun. We watch TV that way and communicate with the world. It may be that 30 minute downtimes are not a big deal if we just do what we were going to do sitting at home or work. High speed internet makes sense as a must at any charging station where people might otherwise wait. Many cars are getting pretty large screens and good sound, too.
That’s if we have the discipline to accept that if we watched Netflix
Above is an image of the sort of charging station Electrify America (the large charging network created as part of VW’s “dieselgate” recompense) wants to build, with a lounge and other amenities to wait. Tesla has a station like this in Central California. If you do have no other choice but to wait, it is nice to have a station like this, but it probably should’t be the goal. Many stations would do well to at least have things like a place to eat (even picnic tables) so people can bring take-out they pick up on the way to the charging station, so that you are eating, not waiting, while charging.
Electrify America is almost entirely about large fast-charging stations, and funded by a fossil fuel scandal, so it’s not surprising they have gasoline thinking. And many customers still retain gasoline thinking, so their stations will get used, at least for a while.
Shell has a big electrification plan, and has partnered in Europe with Chinese OEMs Nio and BVD to build a big charging network for them, starting with chargers in gas stations. Better than nothing, but you have to expect gasoline thinking from an oil company.
Swap
Perhaps the ultimate expression of “gasoline thinking” is battery swap. The issues around this are detailed in this article about Ample, a swap company. Swap does not make sense for most daily and urban charging, it could have merit on road trips. It could also have merit for road trips as battery addition rather than swapping, to produce a temporary increase in range.
Magic charging
The best possible charging, however, is charging that just happens magically, because you have a car that charges itself. It may not be able to drive you around for a few years, but it’s a much simpler problem to develop cars that can self-drive short distances on quiet streets at night or in the morning. Such cars will simply take themselves to charging stations any time it looks like you don’t need them for a while — including while at work or asleep.
That’s something vastly better than any other car. A car that’s simply always full, and you aren’t even aware of how it does it. That’s coming. It may come fairly soon, making most of the plans for complex charging infrastructure obsolete before they are fully built.
To happen, this requires a primitive low-speed short-distance self-drive ability, and the presence of charging hubs within a few miles of places people park. It requires large charging hubs either with human plug-jockey service (adding a cost per charge) or some future robotic self-plugging connector — or better still a plug on the back of the car that allows the car to do the robotics. Office parking lots with daytime charging for employees might be ideal for this, or locations near power substations. These things are in the future, but not that far in the future.
While you drive?
Some people hope they can get a solar panel on their car that charges while they drive or park. While this can do something, and allow you to charge less often in ultra-efficient cars, it’s generally not a great or green idea. The solar panel on a car is expensive to install, and throws away all its power if the battery is nearly full. It also only works when the car is parked in full sun, but it never does as good a job as a panel on a rooftop which is kept in full sun and tilted at the right angle — and feeds all the power it makes into the grid if you don’t use it on site. If you have $900 to spend on solar panels, putting them on your house will probably be 3 times more effective at reducing emissions than putting them on your car — but on some specialty cars you might go a few more days without charging. (Good for you, bad for the planet.)
Chargers every 50 miles
The Biden plan calls for chargers every 50 miles along significant roads. That’s a lot of chargers, and some will get low usage, but it would remove all doubts that you can take your EV anywhere. While gasoline users sometimes run out of gas, that is much less frequent with EV drivers. (Roadside service providers report that while gas can service is common with other cars, calls to service an EV with an empty battery are rare.) EVs track energy usage precisely and EV drivers currently plan recharging more than gasoline drivers do.
If these rural stations can be placed at places people want to stop, then they can meet the criteria of avoiding having to wait while charging. In reality though, some will no doubt go at rest stops and other unexciting places. Good wifi might well do the trick, but good planners would try to favor locations which have activities they already wanted to do.
The Solar Flip
Right now, electric demand is lowest at night and power is cheapest at night. We plan to add vast amounts of solar power to the grid — it’s now cheaper than building any other kind of power plant — but these, of course, provide power only during the day. In fact, it means a large surplus of power from 7am to about 3pm, when the high demand peak (from 3pm to 9pm) starts. No car should charge from 3pm to 9pm that can avoid it, but cars are an excellent place to store the solar surplus from the morning.
This means cars will eventually want to stop charging during the night and move to the first part of the day. Sadly, that eliminates charging during the ideal time of sleep, and will move more of it to where cars park in the day, namely at work. Some cars remain at home but still will want to charge in that early part of the day. Night demand will still be low, and some cars really can only charge at night, including cars at hotels or cars that drive around all day. They will still charge at night but need to get their power from baseload or storage. Cars that can will be encouraged to charge in the early day.
In fact, there will be strong motive to have cars plug in as much as they can during the solar surplus. These cars will plug in, but unless they need it, they will only charge when the power company is offering surplus power at a cheap discount. Which it will, because, if you don’t sell solar power, it is wasted. You either store it or take any price better than the margin on storing it. Cars combine that, because they store it (for driving, not currently for the grid) and will do so on command. You might find most cars filling up on a sunny cool day, but skipping charging if they don’t need it when the clouds roll in or the weather gets hot and all the buildings need air conditioning. Of course, if the driver really needs the power, they will buy it at the higher prices of non-surplus days, as they do now.
Planning charging
As we rush to provide charging to meet the growing demand for electric cars, we want to make sure we do it right. Outside the home, the cost of EV charging is more about the service than the electrical energy. If we put in a lot of charging infrastructure to serve people who can’t charge at home or work, it may become underused in time. If most cars by 2030 can drive themselves to charging, then charging at the store may be a waste unless it’s the kind robots can use at night. Road trips will need fast charging but we want to put it where we eat and shop or take a work break.
The biggest legal changes needed aren’t money. Instead, rules are needed to get charging put into apartment parking lots and office parking, and rules should change to make it easier to put charging in homes — the market will respond with products to meet the demand and use the new rules. Electrical codes should be updated to support and encourage smart charging devices that watch other current in the house to prevent overloads, allowing most houses to install charging without increasing their electrical service. And we need to get ready for the solar flip, where the office becomes the primary charging location for car commuters.
Source: https://www.forbes.com/sites/bradtempleton/2022/03/30/its-not-where-charge-an-ev-its-what-you-do-while-charging/