Monitoring EV running costs

[staffordian]

A hypothetical question at the moment, but I imagine my next car purchase might well be an EV.

I am a bit of a geek when it comes to monitoring motoring costs, and it is very simple to note how many litres of petrol I buy and how much it costs. Therefore accurate mpg figures and data such as cost per mile can easily be calculated.

How easy is it to do with an EV?

If I have a home charger, does it, or does the typical EV itself record the amount of charge put into the vehicle per charge, or over a period of time?

And what about the cost of that electricity? Easy enough on a fixed tariff, but what if on a flexible tariff where cost varies per hour?

Then, if I get a free top up using the local Tesco charger, does that tell you how much juice it has given you? There, at least, the cost is easy to calculate

And I assume if out and about, the public chargers will tell you the amount of energy purchased, and your credit card, or the charger display will reveal the cost.

I imagine these questions don't have definitive answers as chargers and cars will vary, but I wondered if there were any general principles which hold good.

TIA for any insights.

[AF62]

The answers to all those questions are ‘sort of’.

My EV, a Renault, doesn’t show the charge you have put into it, but does show how much charge has been consumed. However the information is somewhere in the car’s system as third party apps can connect to the car and pull out the information out from wherever it is.

The EV charger I use at home, an Ohme, does show the historical energy used and the cost of the energy - I have a smart meter tariff and the charger and electricity network talk to each other so it knows only to charge when cheap.

As an aside, you really wouldn’t want to regularly charge an EV at home if you didn’t have a smart meter and dedicated EV tariff to take advantage of the cheap off-peak electricity.

Out and about I mainly use PodPoint chargers as they are frequently free at supermarkets and retail parks, and their app will give a summary of use and charge input into the car.

However… the cost of the electricity is so cheap in comparison to petrol, when considering the cost of ownership it is the smallest number and almost gets lost in the rounding.

[Howard]

I'm a fellow automotive geek who has tracked motoring costs over the years. In my experience it's very easy to track the energy consumption of our KIA BEV. The smart charger in the garage tracks exactly how much electricity has been used. For example, its app on my phone will tell me exactly how much charge went in on a particular day last year. And, of course, it will give me a total for a given time period.

However, our BEV is a second car, so I've only once plugged it into a public charger for fun. I used a Geniepoint charger and their app still records the event about 9 months ago!

As our BEV has a range of between 250 and 300 miles depending on speed of driving/wind speed/temperature etc we have never needed to use public chargers. We have an ICE car with a range of 600 miles for longer journeys.

The BEV also records how much charge it has received on its app. It can also be set to only charge between 12.30 am and 4.00 am which is the period when Octopus charge only 5p per kWh. Given its usage as a second car, we have never needed to charge outside that time window as the car can be topped up to 100% the evening before a long trip. (It's normally not charged above 80%).

Hope that answers some of your questions.

It's worth adding that the cost of running the car is low. The fuel cost is around a quarter of the cost of running our previous petrol Golf. I was lucky in timing the acquisition of the car so the overall cost of the car was similar to a new Golf.

Obviously we don't know how much we'll be paying for electricity later in the year when our fixed price agreement runs out!

regards

Howard

[staffordian]

The answers to all those questions are ‘sort of’.

My EV, a Renault, doesn’t show the charge you have put into it, but does show how much charge has been consumed. However the information is somewhere in the car’s system as third party apps can connect to the car and pull out the information out from wherever it is.

The EV charger I use at home, an Ohme, does show the historical energy used and the cost of the energy - I have a smart meter tariff and the charger and electricity network talk to each other so it knows only to charge when cheap.

As an aside, you really wouldn’t want to regularly charge an EV at home if you didn’t have a smart meter and dedicated EV tariff to take advantage of the cheap off-peak electricity.

Out and about I mainly use PodPoint chargers as they are frequently free at supermarkets and retail parks, and their app will give a summary of use and charge input into the car.

However… the cost of the electricity is so cheap in comparison to petrol, when considering the cost of ownership it is the smallest number and almost gets lost in the rounding.

Thanks, some useful information and interesting thoughts.

I guess one of my reasons for asking about cost is that (sadly!) I also monitor my home gas and electricity consumption and just lumping car charging costs in with home electricity consumption seemed wrong, but yes, given the relatively insignificant cost compared to other higher figures, such as purchase, depreciation, insurance etc, its probably not worth worrying about, especially as I'm a low mileage driver these days. And this aspect is one reason for not jumping into EV ownership. Even my petrol costs are modest, so the scope for savings with an EV are rather limited.

[scotview]

Our Zappi home charger shows car and home consumption in graphical form, examples attached from the app.

[bluedonkey]

As I'm sure you are aware, the fuel costs are a small part of the total costs which will also include insurance, depreciation, servicing, etc.

[staffordian]

As I'm sure you are aware, the fuel costs are a small part of the total costs which will also include insurance, depreciation, servicing, etc.

Certainly. The query was more to satisfy my inner geek, than in any way influencing any purchasing decision

[DrFfybes]

As I'm sure you are aware, the fuel costs are a small part of the total costs which will also include insurance, depreciation, servicing, etc.

Certainly. The query was more to satisfy my inner geek, than in any way influencing any purchasing decision

On a new(ish) car with average, most things are dwarfed by depreciationt. At 40mpg and 6000 miles per year you are looking around £1000 on petrol, so 3 or 4 months' rental spent on fuel. With a BEV it is even less, bluedonkey is correct that the charging cost will really not matter.

Can I suggest your next car should be a large engined V8 or V12. Preferably Italian, but British would be fine, or even a US V8.

Not only will it be easier to monitor your motoring costs (you simply count the increase in "bank balance below alert level" emails), but quite soon you will find your inner geek finds something else to focus on.

Like the running costs of a 14 year old Rescue Dog

Paul

[Howard]

For me, the total cost of leasing a KIA BEV for three years is virtually the same as the best quote I got for a lower spec ICE Golf. Insurance is the same.

And for sad souls like me who used to drive a supercharged V8 Jag XKR, should I want to, our BEV will match or embarrassingly out-accelerate all but the most powerful ICE cars from a standing start to 30 mph and probababy to around 50 mph. (Less wheel spin on a damp road because of the extra weight).

And it's infotainment, Sat Nav, and all the uneccessary gismos of a new car are excellent.

What's not to like?

regards

Howard

PS Only extra cost is the fitting of the charger in the garage.

[AF62]

I guess one of my reasons for asking about cost is that (sadly!) I also monitor my home gas and electricity consumption and just lumping car charging costs in with home electricity consumption seemed wrong

Then you would love the data you can get with a smart meter - my electricity bill runs to 30 pages or more of close typed print showing the consumption every 30 minutes!

But seriously, the data can be downloaded to a spreadsheet and as my usage overnight is predictable as the house is just ‘ticking over’ in the early hours then it is obvious when the EV has been plugged in as the consumption suddenly increases by 7.4kWh, so it wouldn’t be hard to identify those peaks, add them up and deduct an average ‘non-charging’ use.

[genou]

Then you would love the data you can get with a smart meter - my electricity bill runs to 30 pages or more of close typed print showing the consumption every 30 minutes!

In this context the OP could look at something like

https://www.ebay.co.uk/itm/373217391368 ... 2749.l2649

There is quite a lot of data to be had from a BEV.

[staffordian]

I guess one of my reasons for asking about cost is that (sadly!) I also monitor my home gas and electricity consumption and just lumping car charging costs in with home electricity consumption seemed wrong

Then you would love the data you can get with a smart meter - my electricity bill runs to 30 pages or more of close typed print showing the consumption every 30 minutes!

But seriously, the data can be downloaded to a spreadsheet and as my usage overnight is predictable as the house is just ‘ticking over’ in the early hours then it is obvious when the EV has been plugged in as the consumption suddenly increases by 7.4kWh, so it wouldn’t be hard to identify those peaks, add them up and deduct an average ‘non-charging’ use.

Consumption every month is enough for me

But good point regarding overnight usage differences. That would probably be accurate enough.

[Howard]

I guess one of my reasons for asking about cost is that (sadly!) I also monitor my home gas and electricity consumption and just lumping car charging costs in with home electricity consumption seemed wrong

Then you would love the data you can get with a smart meter - my electricity bill runs to 30 pages or more of close typed print showing the consumption every 30 minutes!

But seriously, the data can be downloaded to a spreadsheet and as my usage overnight is predictable as the house is just ‘ticking over’ in the early hours then it is obvious when the EV has been plugged in as the consumption suddenly increases by 7.4kWh, so it wouldn’t be hard to identify those peaks, add them up and deduct an average ‘non-charging’ use.

Consumption every month is enough for me

But good point regarding overnight usage differences. That would probably be accurate enough.

The amount of money per month is pretty tiny if, as you say, you are doing a low mileage. Hardly worth bothering about?

Our BEV does just under 4 miles per kWh, so at 5p per kWh and an annual mileage of 5,000 miles the current extra cost of electricity to run the car is around £6 per month. We only charge at off peak rates.

Obviously electricity prices are likely to go up but even if they double or treble it won't be a lot, compared with our heating and lighting bills.

regards

Howard

[9873210]

The amount of money per month is pretty tiny if, as you say, you are doing a low mileage. Hardly worth bothering about?

Our BEV does just under 4 miles per kWh, so at 5p per kWh and an annual mileage of 5,000 miles the current extra cost of electricity to run the car is around £6 per month. We only charge at off peak rates.

Obviously electricity prices are likely to go up but even if they double or treble it won't be a lot, compared with our heating and lighting bills.

regards

Howard

The reason your costs are so low is because you are bothering.

The average electric cost is closer to 20p/kWh than 5p. Not bothering could easily triple or quadruple your cost. If you really not bothered you could charge at a peak rate and increase the cost by a factor of about 10.

As more and more renewables come online there will be changes to the tariffs. The details on when and how to charge to get the best prices will change. Nobody knows exactly how this will pan out, but somebody, somewhere will fail to notice that off-peak has moved from say the middle of the night to the middle of the day and end up with ridiculously high bills because they did not adjust their behaviour. This will not happen to people who are paying a little bit of attention. That doesn't mean you have to obsess with daily spreadsheets, but some minimal attention should be paid.

[Midsmartin]

You'd imagine that a smart home charger might talk to your smart Meter and just know when off peak power is available. I don't imagine we are there yet. Our smart meter seems as thick as a short plank.

[Urbandreamer]

You'd imagine that a smart home charger might talk to your smart Meter and just know when off peak power is available. I don't imagine we are there yet. Our smart meter seems as thick as a short plank.

There are trials out there, though I think that the charger communicates directly with the grid.

The buzz word to google is V2G (Vehicle to grid).

https://www.ofgem.gov.uk/publications/c ... g-charging
https://www.theade.co.uk/news/market-ne ... ity-market
https://chargedevs.com/newswire/london- ... ker-buses/

I did actually briefly mention the idea in the crypto currency thread, as consuming energy during periods of high availability would enable us to install "too many" wind generators. That would mean enough renewable energy for important uses when there was less wind and reduce our CO2 output.

However arguably using EV batteries is a better solution, as it could mean that less resources needs spending on transmission wires from generators to cities.

[9873210]

I did actually briefly mention the idea in the crypto currency thread, as consuming energy during periods of high availability would enable us to install "too many" wind generators. That would mean enough renewable energy for important uses when there was less wind and reduce our CO2 output.

However arguably using EV batteries is a better solution, as it could mean that less resources needs spending on transmission wires from generators to cities.

All of the above, plus a lot more. Plus money, because an accurate pricing mechanism is the best method we know of for making complex decisions like whether it is better to spend more on transmission wires or to collocate supply and demand.

[AF62]

You'd imagine that a smart home charger might talk to your smart Meter and just know when off peak power is available. I don't imagine we are there yet. Our smart meter seems as thick as a short plank.

We are there.

My Ohme EV charger communicates with the energy supply network through a built in SIM card.

It knows what tariff I have, when the cheap rates are and what the maximum electricity price I am prepared to pay.

It also knows what car I have and talks to the car (which also has built in SIM card) to establish how much charge the car requires and how long it will take to charge to the capacity I have set for that session, in order to work out when to switch on.

So get home, plug the car in with the knowledge that charging will only start when the electricity price falls below that pricing level.

[AF62]

However arguably using EV batteries is a better solution, as it could mean that less resources needs spending on transmission wires from generators to cities.

This will never happen unless there is a substantial, and I mean *substantial*, payment for the use of an EV’s battery to top up the grid.

Firstly the vast majority of EVs are not plugged in most of the time; why would they be! With a range in hundreds of miles most EVs only need to be charged every week or so. Suggesting EVs could feed the grid is like suggesting petrol cars could supply the oil pipelines because they are ‘connected’ to it when filling up.

Secondly, when EVs are plugged in it is because they don’t have sufficient charge and the user wants the car to be fully charged when they unplug it. If the network is taking charge from the car that just won’t happen.

And that is before you get to the cost of the extra electronics needed for the two way supply in the car, the additional wear on the battery, the extra electronics needed for the two way supply from the charger to the grid.

It just isn’t ever going to happen.

[Urbandreamer]

However arguably using EV batteries is a better solution, as it could mean that less resources needs spending on transmission wires from generators to cities.

This will never happen unless there is a substantial, and I mean *substantial*, payment for the use of an EV’s battery to top up the grid.

I don't entirely disagree with you.

However I would point out that much the same was said of solar panels. True, that hasn't "happened" in bulk. The point is that it has happened enough that the statement could not be held to be true of them. Indeed you can even buy shares in an investment trust hoping to profit from the roof space of industrial and commercial buildings. Presumably your concern about 2 way electricity has been solved for each solar panel installation.

Then again, it is not entirely unknown for some people to seek out options that they consider to have environmental benefits, without financial benefits. I believe that a number of electricity providers offer tariffs with the promise that the electricity comes entirely from renewable sources. Indeed some already offer special tariffs for those with an EV charger as well. ie
https://www.britishgas.co.uk/energy/ev-tariff-home.html
No doubt there are others.
Would it be too far a stretch to imagine a V2G tariff in the future? Oh, sorry, this company does have one. (there are others)
https://www.ovoenergy.com/guides/demand-side-response

As for a car with a range of in excess of 100 miles being left discharged before the work commute, it would be unlikely in the morning and if plugged in at work (work being on a V2G tariff), then surely the car can know the likely commute distance and ensure that it has enough energy. That is unless you tell it that you need it to have a full charge. Indeed it's likely that the car would even roughly know when you are likely to use it. Extra computing power? Now you are having a laugh. All modern cars are computers on wheels and some receive software updates via the phone network as you use them.

Why would someone leave an EV plugged in? During winter or summer when they want to get into a car with a comfortable temperature? No need to drain the battery before you drive. Indeed in some parts of the world they plug their petrol cars in overnight, either for the same reason or so that the car can start.
https://www.minit-tune.com/blog/everyth ... ck-heaters

Most vehicles sold in Canada come with a block heater as a standard feature.

By the way, did you follow any of the previous links? The Ofgem one mentioned a possible payment of £725pa. I would agree that isn't substantial, but it might be significant. Especially were one to lease rather than own the car and hence battery. Others were large businesses who presumably are not doing it totally altruistically.

Finally, have you considered the possibility of regulation? The law now requires that a EV charger be fitted to any new house built. How large a stretch would it be for Ofgem, you know the author of the first link, to regulate on such chargers.

Never? Well you might be right.