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Nov 09, 2024

Flexible EV charging prices prove to be good for solar soak, and it stopped ICEing

A South Australian study into EV driver behaviour has found that pricing charging stations correctly in the middle of the day can help soak up excess energy in the grid and help stop ICEing behaviour

A South Australian study into EV driver behaviour has found that pricing charging stations correctly in the middle of the day can help soak up excess energy in the grid and help stop ICEing behaviour by keeping the spot busy enough to stop incidents.

The study was one of nine commissioned by the South Australian government’s Department of Mines and Energy investigating different aspects of driver behaviour across the state to address concerns about the perceived impact of EV charging on the grid.

With the high penetration of rooftop solar and other renewables across South Australia, and the gradual increase in EV drivers on the state’s roads, it has been argued that charging could be used to help “soak up” excess power generated at peak times in the middle of the day.

Researchers considered whether changing the price at the charging station could influence the behaviour of drivers in any way, which could then be used to encourage more charging at peak times.

The study, conducted by fast-charging network operator ChargeFox, was among the first to begin and involved monitoring the way drivers used a DC fast-charging station at Port Adelaide Plaza in Adelaide’s western suburbs.

Over the course of the trial, researchers monitored activity at the station and interviewed drivers to better understand their decision making.

Miles Menegon, lead researcher at the company, said that the study initially assumed, based on other research the company had undertaken, that price would not make much difference on driver behaviour.

Past work suggested that “early adopter” EV drivers at that time tended to be middle aged men with disposable income who did not factor the cost of charging when making their decision.

“Over the course of the study, which was many months long and over a series of different experiments we ran, we found, surprise, surprise, price did have an impact,” Menegon said. “There were caveats, though: you can change pricing to encourage drivers to charge at different times of day, but they have to be the right driver.”

Menegon said EV drivers fell into two broad categories; “need to charge” drivers who will pay what they need to keep themselves on the road, and “want to charge” drivers who can choose when to charge usually because they can do so at home.

The researchers found that the second category, those with the ability to choose, perform a “mental arithmetic” when they leave the house.

This involved a calculation using a rule of thumb that considered variables such as how much they pay to charge at home, how much they thought it had cost to install the public charging station, the distance of travel and what else they might do while they charged, like go to a café or get groceries.

As a result of this, researchers were able to identify what they called a “goldilocks zone” that was lower than the cost of petrol, but did not give the power away for free.

When the price approached the same or higher than the cost of petrol, Menegon said drivers grew angry as they felt it disincentivized people driving electric vehicles, but when it was given away for free, they assumed the station would be unavailable as everyone was trying to use it.

“It’s like a honeypot. All the drivers will go there and it’s inconvenient, nobody wants to wait for a charge,” Menegon said.

The researchers who monitored the site also looked for instances of ICEing – that is where a petrol car, whether intentionally or not, is parked in the charging bay, preventing it from being used. As the charging-station was in a busy suburban carpark near an Australia post, it was frequently blocked by delivery vans prior to the trial.

“When we incentivised drivers to come charge during the middle of the day, and the chargers were being used regularly, that ICEing behaviour almost completely disappeared because there was activity,” he said.

“We talk about, read a lot about ways you can disincentive icing. One of the best ways to do that from these studies is to make sure your charges are very busy all the time so you don’t have a parking spot to actually park in.”

The South Australian Department of Mines and Energy was contacted for comment but did not respond by publication.

Good study. Makes sense. When can we have incentives to public charge in peak solar hours to reduce soaking up coal powered grid? Surely, a no brainer to get us off coal.

What time do you work during the week.Simple question

You asked this a few times. Are you saying it’s impossible to have chargers nearby to work? The train station near me had 20+ AC chargers installed, allowing commuters to slowly charge while at work. There are many examples where incentivising charging through the day will work.

Then couple v2h into the equation after that…

Full report here: SA Government and Chargefox trial shows what drives EV charging behaviour. | Chargefox

I wouldn’t know where to find the rate that is being charged at any one time for a local charge station. If it was uniform and significant I would change my charging habits.

True. NSW government has fuel check, but kWh check I’ve never seen.

Not hard to find. The PlugShare app or website gives you the price of most networks charger’s locations. If not in PlugShare then the app of the network will show it.

encourage MORE charging at peak time??????????

Middle of the day is when most excess power is available and needs soaking up.

When do the majority of people work.During the day

I have lunch in the middle of the day and a 30 min charge session on a 200kW charger will add 600km of range, not many EVs have that range so you will need less time than that.On the days you work from home, bring your lunch, charge up, eat up and return back to work, easy peasy.

Peak supply, not peak demand.

Of course this makes sense. Charge 10c/kWh and they will come.Charge 90c/kWh and your bay will get iced.

But cheaper electrons could and should be the norm all hours of the day with solar canopies and a grid-connected stationary storage battery on site. You can still have cheap midday prices, and high afternoon early evening peak, but overall it should always be cheaper to charge an EV than fill an ice.

Just asking what times do the majority of people work.

Great study, I find it a bit ludicrous that the RAA chargers in SA currently charge the equivalent of $640/MWh for fast charging outside of peak hours, even when the wholesale price is negative!

Hopefully this study will lead to changes and better use of the SA renewable resources, with a good outcome for consumers and a better outcome for the grid.

All charging are based on perceived value and price carries the highest factor in that equation and will stay with perception when there is no other method to separate CPO’s, even these decisions has subtle undertones such as weather, weekends local activities and buy low, sell high thoughts These dynamic prices are already implemented and data clearly shows pricing as the dominant factor in that for instance you can drain the activity on some public chargers close to zero but difficult to do the same for Tesla superchargers (hence other method to separate CPO’s)…… That said the lower values must be leveled for CAPEX+ and EV owners will not easily move if its not at least <= to home charging rates

So, the study found that when a charging bay was occupied it could not be used by a different vehicle.Great work team!And, charging that costs more than fossil fools? Isn’t that known as gouging?Reminds me of when unleaded petrol was introduced. They charged you more for leaving the lead out.Hell, I’m old enough to remember when clunky non retractable seat belts were a novelty.

They want people to charge during the day when most people work.Do I tell the boss I will be back in 3hrs or I charge on weekends and not take the kids to sports.

Tom, pay attention, you are going to learn something.

The power of the charger = the distance added in 10 mins (rule of thumb).

50kW charger will add 50km of range in 10 mins100kW charger will add 100km of range in 10 mins200kW charger will add 200km of range in 10 mins

Most ppl can afford 20 or 30 mins for charging over their lunch break.

EVs don’t have to be fully charged from empty like most ICE vehicles drivers tend to do filing it all the way up. Most ppl don’t wait until their phone is on 5% before they charge and then charge it to 100%. You charge enough to cover your drive with the time you have (fast charging) or charge enough to add sufficient range for the day or next few days and repeat a few times per week, i.e. plug into power point at home charging overnight for a few nights per week.

The like for like mentality catches a lot of ICE drivers out. It’s different most of the time as EVs are better for city driving as most trips per day on average are around 35kms. On a 200kW charger that is quicker than filling up an ICE car empty to full.

ICE drivers will not go to the petrol station 4 times per week, EV drivers might charge that frequently when they top up, which is as quick as plugging your phone in to charge which is multiple times per week, assuming you have access to a power point at home for the EV

There’s no reason chargers might not be near sports fields. In fact public sporting facilities are exactly the right location for chargers – people that go to that location are likely to go for an hour or two, perfect amount of time for charging.

1. Nothing is free.2. Sorry boss I must go charge my ev while the price is low, see you in 2hrs

Tom, don’t be boring. You can’t charge in the middle of the day, got it! As the study showed, some people can.

…a some are even lucky their employers have installed level 2 chargers at work, which also helps “solar soak”. I do nearly all my charging that way! And rarely get concerned about “how long it takes to charge”

Instead, your boss (or others) just install some chargers on site.

Sorry Tom you will have to charge at home on cheap overnight tarrifs if you can.

I charge at home mostly for free off solar and night rates if needed and have been bewildered by the blatant gouging at the DC chargers especially during the day. As more infrastructure gets built competition should lower the cost and hopefully discount TOU tarrifs will become prevalent.