Soon enough, all cars will be electric. Electric cars already cost less per kilometre and have lower maintenance costs than their fire-breathing cousins. Soon, they will be cheaper to buy.
The first to benefit (and those who will benefit the most) will be the “Driveways” who have solar panels on their roof and a driveway onto their block. The sun will fuel their cars and kms for free.
If you are a “Driveway” and you do not have an electric car, put down whatever you are doing, and get hold of one as soon as possible. Otherwise, in the words of the late Fred Dagg, you are a fool to yourself and burden to others.
It is a longer road for the “Apartamentos.” First, they will need to convince the Owners Corporation to run cables, install meters and software in the basement car park. Then, they will need to convince the OC to install solar panels or sign up to a fancy retail tariff that trades cheap midday power.
These challenges will be character building. But rewards await. The Apartamentos (and the Driveways) will soon be paid to soak up midday solar in the battery of their idle car and then get paid to sell some of it back overnight. It will be a Magic Pudding.
Probably the last to join the electric party will be non-owners and occasional drivers. These folks will not be able to enjoy electric motoring until the car share and care hire companies make the switch. Car share went electric in Quebec years ago, but our service providers are waiting until electric driving and charging becomes the norm.
Kerbies
That leaves the “Kerbies” – people like me who live in the inner city and have an electric car that they store overnight on the street. How do we join in on the fun from the sun?
Well, I have some bad news. There no gold rush at the kerb. We will not be able to travel on our homebrew power or have our cars (and bank accounts) absorb surplus solar power at the kerb like a lungfish. We will need to keep buying fuel from a public network, just like our parents. This is likely to cost us around $1,500 a year.
This rubbery estimate is based on the Australian average vehicle kilometres travelled (11,200 km), an mpg of 20kWh for every 100km and a cost of 64¢ per kWh.
Likely if you are Kerbie, you will not travel as far (by car). Likely, you will get hold of a vehicle that only needs 15kWh per 100km, and, who knows, you may be able to plug in at a friend’s place from time to time.
What about your Kerbie neighbour with a brand-new petrol Yaris? If they travel 11,200km each year and the car detonates 5 litres every 100km and the cost is $2 a litre they will be paying $1,100 a year for fuel. Less than you.
Of course, your neighbour may have a bigger, heavier, older car and pay $1,600 for fuel. In that case, you would be in front by a Nellie Melba. You will also be in front on maintenance costs and the fun of electric motoring.
The take home message is that if you are a Kerbie and can afford to run a car, you can go electric today. But there will no free fuel bonus.
Kerbie charging
How do you charge an electric car if you are a Kerbie?
It is important to know that you are not permitted to run an extension cord across the footpath. The idea is tempting, but no one wants public liability lawyers crawling all over them.
One Melbourne Kerbie Council is trialling private power at the public kerb. The system is basically an entrenched extension cord that runs from your house to the kerb. A creative designer and fabricator has built this solution from scratch and it is in use in a trial.
The technical problems have been solved but the public/private thing remains unresolved. Let’s put those issues aside. Clever as this solution is, it will not fill your car for free.
If we spread the upfront and annual costs over ten years, it is going to cost you ~$800 a year plus power. To fuel the full Kerbie fleet this way, we would need one of these for each Kerbie household.
The main and immediate option for a Kerbie is charging through the DC public charging network.
This network is made up of several vendors (red, yellow, and blue). The DC power comes from a cabinet that looks just like a petrol bowser. Mostly the ‘pumps’ are on private land (under the supermarket for example) and nearly all are away from the kerb in off-street car parks.
An exception can be found in the twin towns of Korumburra and Leongatha. For some reason they sited their DC chargers at the kerb. It must be quite exciting plugging in a BYD on the driver’s side while standing in traffic on the South Gippsland Highway.
If you are lucky, you will live in a Kerbie area where DC chargers are beginning to become available. For us there is a DC charger in the parking lot near the big shopping centre, one at the library and a new one at the supermarket. Soon, they say, there will be another at the local pool.
Typically, we fill up on the way back home when not under time pressure, rather than trying to jam in a charge before a deadline.
Charge times vary for several reasons including the top speed of the charge unit. To give you an idea about fill time, I did two part-fills recently on the blue network. A 17 kWh fill took 32 minutes at a 50 kWh charger. A 20 kWh fill at a 75kWh charger took 22 minutes.
The DC network is still in its adolescence, growing in an ungainly manner. The Blue network can now recognise the car when you plug it in. This allows you leave your phone in your pocket.
However, it does not accept two drivers, so it sends to my bill to Jeanette. Long may this last. When charging is nearly complete, it also sends the ‘go back to your car’ note to her, even when she is 100km away from the vehicle. So, work to do.
Other clumsiness is less entertaining. You may arrive at the charge point and find it occupied. Although you can book a dentist, gym session, or dinner reservation in advance, you cannot pre-pay and schedule a charging session. I am not sure why.
To sum up, a new DC-based servo system is emerging and steadily getting bigger, faster, and better.
Count the DC chargers
If Kerbies only had access to a DC network, how many charge units would there need to be?
We know that there are 45,000 cars in the resident fleet in my municipality. We do not know how many car owners are Kerbies. Let us use 1,000 as our example and then, when we find out the actual number, we can multiply easily.
In the rubbery estimate above we are using a rubbery vehicle. The rubber vehicle travels 300km on a charge, has a battery capacity of 60kWh, and always fills from completely empty to completely full.
To travel the average distance, the rubber car will need 37 fills each year. Each charge is at a constant 50kWh and takes 1.2 hours. The car will be at the power pump for 45 hours a year. Let us assume that all these charges take place in the municipality. Don’t you love models?
To estimate the number of DC bowsers, we need to define the active charging time. The chargers will be available 24/7 but for some hours people will be in bed. Let’s say the system is ‘open’ for 15 hours (07:00 to 22:00). Now we can say that each charge bay can support 123 vehicles, and we will need 8 DC charge units for a 1,000 Kerbie fleet.
That estimate is only true if there is maximum changeover efficiency, with no lost time when the bay is empty or when someone overstays. It is difficult to know how inefficient real life is or will be at a DC charging bay.
Let’s not put a number to it, otherwise it might look like we know more than we do. Instead, let’s round our estimate to one DC charger for every 100 Kerbies or ten DC chargers for a fleet of one thousand. That is neat and probably not very wrong.
AC charging at the kerb
You do not have to hang around the inner city or listen to discussions about vehicle electrification for long before you hear the cry of a Kerbie who yearns for AC charging at the kerb.
I would like to hear focus groups discuss this desire. It seems illogical—why want a network that, even at its best (25kWh), can only be twice as slow as the slowest DC charger?
Maybe people believe kerbside charging through AC is cheap or free or more convenient. Perhaps they do not yet have an electric car and so have no experience of the DC network except on social media. Perhaps there are no DC chargers in their area.
Let’s examine the AC system. We can study the theory using the rubbery model car and compare the theory with trials in Sydney and long-term results in London.
An AC system is relatively inexpensive to install – you stick a plug on the pole and run a cable up to the wires above. From a power perspective there are few location constraints. A car at an AC charger sips through a straw, so a plug can be installed on any power pole. By contrast, DC chargers are costly. They also draw significant power and can only be installed where there is surplus energy.
The monopoly electricity distribution businesses support AC charging as it generates additional income and gets them in touch with consumers. Better still they can get a government grant to set it up. Governments like the idea because they get to be seen to be doing something about vehicle electrification. There are several more impactful things that governments could be supporting in the world of four-wheel electrification, but that is another conversation.
Using an AC system
Now let’s look at what people like to call the user ‘experience’.
The cost of AC charging is relatively high. It varies but you can expect to pay 50¢ a kWh. (Double the retail cost of plugging in at home.) Nonetheless, the lower fee cuts the DC charge bill by $313 a year. Now the electric Kerbie is paying the same fuel bill as their neighbour with a Kerbie Yaris. There may be other cots. Not every pole charger has a cable, so you may need to buy a car-to-pole cable. These cables can cost a couple of hundred dollars.
The other two factors are time and space. Thank you, Mr Newton.
Our rubbery car still needs 37 fills each year but now the process will take twice as long – 2.4 hours for a fill. (The maximum AC charge speed is 25kWh while the slowest DC speed is 50kWh).
Because our AC charge is going to take 2.4 hours, the user will probably seek to run the charge while they are at home and doing other things, rather than when out and about and doing other things. London has found that the most popular AC kerbside charge time is 16:00 – 19:00.
Perhaps the AC charging Kerbie would seek to plug in on the way home from work. Let us say 18:00. First, they would look for a bay near home that the app says is available. (These bays will not have CCTV so there may be a vehicle in the bay that is not connected.) Then, when they find a vacant AC charging bay, they plug in and walk the rest of the way home.
If the DC user plugs in at the same time, they will be later home but will not need to go out again.
The AC charger’s phone will ping at 20:15, and they will walk back to the car and drive it back home, hoping to find a vacant bay. The next Kerbie will see that the charge bay is free, jump off the sofa and drive to the charge point before anyone else gets there. Let’s say they plug in at 20:30 and then walk home. When they finish their charge at around 11pm, they will need to hoof it back to their car and bring it home.
All being well, that kerbside AC charge bay will charge 6 cars across the day. But to achieve that someone must get up and plug in at 07:00. Would that suit you?
Sydney
Let us now look at some in-action information from Sydney.
Their kerbside AC chargers run at 7kWh or 22kWh, both somewhat slower than the 25kWh in our model.
A manager of a group of AC bays said they can get 2,000 charges a year out of a bay. That translates into 5.5 charges a day, roughly what our model suggested. If they have a 15-hour span of activity, then the charge periods average ~2.7 hours, again close to the model.
What do you get from a 2.7-hour charge? Not much if the charger runs at 7kWh. Three hours at 7kWh charge gives you a ~20kWh charge. (You will remember that a 20kWh charge took 20 minutes at a fast charger.) To get a 7kWh charger to fill our rubber car from bottom to top would take 8 hours.
That explains the report from London which said that people stay in the charge bay for 8 hours, charge for 5 hours and each bay hosts 2 sessions each day. At that level of use each bay will only support 20 Kerbies (compared to 123 at a DC charger).
A 22kWh AC charger is three times better than slow kerbside AC. We get close to a full charge of 60kWh in ~2.7 hours. We can support 54 Kerbies from one bay and we will need ~18 bays for 1,000 time-efficient Kerbies. Let us round that up to 22 bays.
Space
Let us now think about the effect a complete AC charge system will have on space at the kerb. There is a lot going on at the kerb – as any Kerbie knows – and the AC system will need to kick people out to set up the charging bays.
Rather than 10 off-street DC bays for 1,000 Kerbie cars, according to Sydney, our best case is 22 AC bays at the kerb. Likely we will need more.
If one third of the local fleet are Kerbies, then at some point we will need to charge 15,000 Kerbie cars. Our options are 150 DC bays in off-street locations (fewer if the chargers are faster) or on AC 330 bays (Sydney) or 750 bays (London). The lower the charge rate, the more AC bays we will need.
I would not like to be the one who must explain to the businesses, permit holders and those who would like street trees that we are going to pull out 350 or 750 kerbside parking bays and turn them into AC charging bays. Indeed, some push back against kerbside charging has already occurred in Sydney.
I should let you go so you can walk back to your car and unplug it. But before you go, the final thing to note is the difference between the catchment of a DC and an AC charge bay.
A DC charger draws people from miles around. ‘I have never been here before’ said the driver of the car at the adjoining DC charging bay as she headed into the supermarket. Every additional DC charger helps everyone in the municipality (and beyond).
By contrast, the AC charge bay must be within walking distance of your home. 20 DC units would support 2,000 Kerbies across the municipality. But an additional 20 AC units in streets 3km away from my place will be of no use to me at all.
I’m sticking with DC, how about you?
Harry Barber is a transport consultant based in Melbourne.