Congestion at electric vehicle charging stations seems to be a rapidly emerging issue.
The recent influx of second generation EVs, with their greater range, is enticing many more drivers into taking regional or longer distance EV road trips.
A lot of us now seem to be turning up at the same charger at the same time.
In a recent road trip article I wrote for The Driven, I described a congestion situation at the NRMA charger at Mittagong which generated lots of comments.
As a result of these comments, and discussions with friends, I think it is worthwhile airing some possible responses to this situation.
In the long term, I assume we will reach a state of equilibrium and the supply of chargers will more or less meet demand. The challenge is in the short term as we navigate the ICE to EV transition.
How can we use our chargers most effectively?
In this article I want to focus my comments on congestion at en route rapid chargers which are mainly used by travellers.
Managing congestion at destination chargers is quite a different issue – I’ve been caught out a few times by that problem as well.
At the Charger
Encouraging drivers to stay with their car
It seems to me that a lot of the congestion ill-feeling is generated by drivers who simply hook‑up their cars for a full charge and then disappear.
A simple solution to this situation would be to incorporate some form of timer into all chargers.
At the end of a specified time period a charger would be designed to halt charging and release the cable (this could require some modification to current car design rules).
I think a maximum charge time of 30 mins would be appropriate. This amount of time would allow the driver to have a toilet break and grab a cup of coffee.
Thirty minutes of DC charging takes our Leaf from 20% to 80% full. If there is no queue the driver can simply re‑start the charging if desired.
Remove free charging
At the moment many EV chargers do not have a monetary charge.
This is providing a strong incentive for local drivers to regularly charge their cars at en route chargers.
I look forward to the day when all chargers impose a cost and believe that the cost of the electricity should be more than domestic rates so that charging at home is cheaper.
Having said that, I recognise that some EV owners without the ability to charge at home (eg apartment dwellers; houses without off‑street parking) will often have little choice but to ‘fill up’ at chargers used by travellers.
Notices encouraging reasonable behaviour
I would like to see some form of charging behaviour protocol developed and have this prominently displayed on chargers.
I don’t think it’s too hard to think of a list of ‘dos and don’ts’ which most of us would like to see adhered to.
These would in effect just seek that EV drivers consider other people and be aware of the inconvenience they can cause other travellers through thoughtless behaviour.
Many people’s response to congestion is simply to say ‘add another charger’. I’m somewhat wary of this approach.
In the first instance, at many current charging locations it is likely to be technically difficult to simply add more chargers due to site constraints (eg lack of power; lack of parking space).
Maybe more importantly, at the moment it seems to me that many of the congestion problems are more related to poor behaviour than real lack of charging capacity.
I would favour behaviour control being introduced before charger replication at any given site.
As more chargers are rolled out across the country I believe careful consideration needs to be given to where they are located. System design is important.
In the long run I can envisage multiple futuristic EV charging stations with all sorts of shops and cafes along the length of our major highways but at this preliminary stage in the transition I think we should aim for having a dispersed charging network.
I believe it is important not to solely concentrate new chargers on a few ‘thick routes’ (eg the Hume Highway) as a kneejerk reaction to intermittent congestion.
I think the NRMA is doing the right thing by spreading its chargers throughout regional centres in NSW. This will hopefully have the effect of dispersing, rather than concentrating, EV travel.
Changing the Mindset
At the moment it seems to me that many EV drivers have a state of mind built around the petrol car: drive fast until you run out of fuel; fill up; and then repeat the process as many times as needed until you get to your destination.
This doesn’t necessarily work for EVs. I believe with a change of mindset we can reduce the amount of rapid charging that is undertaken.
Minimising rapid charging is both good for your EV and good for congestion.
Slow down – you will get there faster!
The efficiency of any car is reduced the faster it goes.
If you hare along in an EV you will use more energy and hence reduce your range.
This will very likely mean you will spend more time waiting at chargers.
On a recent road trip I estimate that we got home at least an hour earlier simply by slowing down to 90km/h rather than sailing along at the speed limit (110km/h) – slowing down enabled us to avoid an en route charging stop.
The faster any EV goes the more heat is generated in the battery.
Managing speed is particularly important in our Nissan Leaf with its passively cooled battery.
It’s not hard to find references to early Leaf 2 drivers who hammered their EVs and found that the resulting heating of the battery, combined with multiple rapid charging events on a long journey, led to progressively slowing charging rates and prolonged travel times.
(This issue was termed ‘rapidgate’ although it is reported that the problem has now essentially been fixed).
If you’re on a road trip I believe the best idea is to keep rapid charging to a minimum and stay at hotels which let you charge your EV overnight.
Less travel time; less congestion at chargers; and better for your battery. I think it would be great if we could encourage more hotels to install destination chargers