EV charging costs and calculation - Real world example. Check my figures?

Bachelorplace

Would anyone like to comment / help identify a summary of true costs and check my figures please?

Car - Ford Mach E: Cost £40,270 
Petrol Equiv - Audi Q3 £29,380 Audi Q5 £41,695

Town driving - with 4 trips at 70mph for approximately 15 mins each. 

Starting Odometer – 13690

Starting Miles range claimed 303 miles

Starting Range 83%

 

Finishing Odometer – 13815

Finishing Range Claimed - 79 miles

Finishing Range 28%

 

Miles covered – 125

Range used 55%

Charging:  

Cost of  single charge from 28% to 77% - £22.00 ( ran out of time to reach 83%)

 

Cost to charge 49% of battery - £22.07

Time to charge  at 50kw charger - 57 minutes.  

Assumptions:

Assumption 1 – Actual miles covered 28% to 83% range = 125 miles

 

Assumption 2 – 55% of range provided 125 miles. In theory 100% of range would provide just over 250 miles and not the claimed 303 miles or less as the car stated 303 miles of range at 83% charge.

 

Assumption 3 – 125 miles cost £22.07 or slightly more because the final charge was 77% and not 83% – Actual miles covered 28% to 83% 125 miles.

Assumption 4 - 125 miles covered in a petrol car would cost £22.51 based on 45mpg or £31.65 at 32mpg. 


Assumption 5 - EV's are not cheaper if you ever plan to charge out of home. And the ranges and power usage is much less accurate than ICE cars. 


Dyscalculia is my middle name, so feel free to make this simpler if you are a maths person or if I am incorrect. 

DrEskimo

Nope seems right. Added about 32kWh from the charge, and are getting about 3.5miles/kWh right?

So the charger must have been around £0.69/kWh, which of course is expensive.
If all you are every doing is using these high cost rapid chargers, then yes about as expensive as fuel, but even when I didn't have home charging I used a slower and cheaper AC charging when I could leave the car for long periods. Was around £0.18/kWh when I did this for a couple of years.

It does show the growing disparity in costs between those that can charge at home, and those that cant, and it's a real problem. I commuted ~75miles today and used about 23kWh of energy. Charging last night cost me £1.17.

Petriix

Yes. These figures seem accurate. There are multiple aggravating factors which compound. 1) driving at 70 mph uses ~ 50% more energy than driving at 50 mph; 2) you charged at one of the most expensive rapid chargers; 3) you're calculating the per mile cost as if your entire journey is charged at that rate.

Typically you'll charge to full the night before your long journey, then you'll only rapid charge sufficiently to arrive home nearly empty. If you're driving less than 250 miles in total then all your charging should be at home at (max) 7.5p per kWh or ~ 2.5p per mile.

If your journey is 400 miles then you only need to rapid charge by about 60% of your battery. Say £25 for the most expensive rapid charging plus £5 to fully recharge at home so ~ 7.5p per mile.

Your suggestion that it's no cheaper than petrol would only be true if you exclusively rapid charged at the most expensive chargers.

The 14,000 miles I've driven in the last 16 months have cost ~ £160 in total. That's 1.15p per mile. Some people are able to charge for free. 

iwb100

DrEskimo said:

Nope seems right. Added about 32kWh from the charge, and are getting about 3.5miles/kWh right?

So the charger must have been around £0.69/kWh, which of course is expensive.
If all you are every doing is using these high cost rapid chargers, then yes about as expensive as fuel, but even when I didn't have home charging I used a slower and cheaper AC charging when I could leave the car for long periods. Was around £0.18/kWh when I did this for a couple of years.

It does show the growing disparity in costs between those that can charge at home, and those that cant, and it's a real problem. I commuted ~75miles today and used about 23kWh of energy. Charging last night cost me £1.17.

Genuine question. Round me the majority of people live in terraced houses with no drive and no parking other than on road. Many are along main roads. They all have cars. Can someone explain when the only option is EVs what are such residents supposed to be doing? How do they home charge? Or do half the population need to be charging elsewhere? 

Right now there is about one charging point for every 10 full EVs. And even now there are reports of sometimes queuing and waiting and problems. People with EVs say it’s getting more difficult.

But let’s say that we have to suffer with just the 1:10 ratio that might be sub optimal but still in this country everything is sub optimal.

That means that even if we reduce cars on the roads by ten percent, that means we need something in the realm of 320,000 charging points. 

And that is based on the current situation where demand is mitigated as only people with drives or charging points at home are buying EVs. So the numbers I have here are not even going to come close to working.

Let’s say conservatively we’d need over half a million charging points. Where are they all going to go? 

Petriix

There are solutions for terraced houses. My local council is operating a permit scheme (with baked in insurance) to allow people to safely trail cables over the pavement. Other areas are installing cable gullies.

Benny2020

We need to follow the example of fairground bumper cars and have a network of chicken wire above motorways so you use a small amount of battery power to get to the main road and then you put your pole up to the chicken wire and use the power from that to power and recharge your car.
 

Cross_Man

Petriix said:

 1) driving at 70 mph uses ~ 50% more energy than driving at 50 mph; 

That impact is the same for an EV and an ICE so should not alter the comparison between the two modes.

Furthermore, EV is not a very good alternative to ICE if EV is also imposing restrictions on speed and potentially increasing journey time.

Bachelorplace

DrEskimo said:

Nope seems right. Added about 32kWh from the charge, and are getting about 3.5miles/kWh right?

So the charger must have been around £0.69/kWh, which of course is expensive.
If all you are every doing is using these high cost rapid chargers, then yes about as expensive as fuel, but even when I didn't have home charging I used a slower and cheaper AC charging when I could leave the car for long periods. Was around £0.18/kWh when I did this for a couple of years.

It does show the growing disparity in costs between those that can charge at home, and those that cant, and it's a real problem. I commuted ~75miles today and used about 23kWh of energy. Charging last night cost me £1.17.

Not bad Esko - 50p 
27p in Brighton
50p Swindon
48p Cirencester
Home - who knows!

I also note the disparity of what "range" means. 

I forgot to mention that the Mach E - shows you 14% use for Aircon 7% for Screen and so on etc etc. This would also mean that if you had say a Tesla which has a decent sound system and an AMP or an IPace which draws more digital power for the interior light pack etc, then this might explain why Telsa's have nothing else in them. 

Much of the driving was on warm days... so at first I was amazed with the usage in relation to what it says it might use. 

But yes that 70mph or any hard acceleration.... at 7c late at night is a shocker. 

iwb100

Petriix said:

There are solutions for terraced houses. My local council is operating a permit scheme (with baked in insurance) to allow people to safely trail cables over the pavement. Other areas are installing cable gullies.

Cables from where? Where are the charging ports? Most of these houses have looped service. So where are they charging from?

DrEskimo

iwb100 said:

DrEskimo said:

Nope seems right. Added about 32kWh from the charge, and are getting about 3.5miles/kWh right?

So the charger must have been around £0.69/kWh, which of course is expensive.
If all you are every doing is using these high cost rapid chargers, then yes about as expensive as fuel, but even when I didn't have home charging I used a slower and cheaper AC charging when I could leave the car for long periods. Was around £0.18/kWh when I did this for a couple of years.

It does show the growing disparity in costs between those that can charge at home, and those that cant, and it's a real problem. I commuted ~75miles today and used about 23kWh of energy. Charging last night cost me £1.17.

Genuine question. Round me the majority of people live in terraced houses with no drive and no parking other than on road. Many are along main roads. They all have cars. Can someone explain when the only option is EVs what are such residents supposed to be doing? How do they home charge? Or do half the population need to be charging elsewhere? 

Right now there is about one charging point for every 10 full EVs. And even now there are reports of sometimes queuing and waiting and problems. People with EVs say it’s getting more difficult.

But let’s say that we have to suffer with just the 1:10 ratio that might be sub optimal but still in this country everything is sub optimal.

That means that even if we reduce cars on the roads by ten percent, that means we need something in the realm of 320,000 charging points. 

And that is based on the current situation where demand is mitigated as only people with drives or charging points at home are buying EVs. So the numbers I have here are not even going to come close to working.

Let’s say conservatively we’d need over half a million charging points. Where are they all going to go? 

No idea.

Needs to be a mixture of approaches I imagine. If upwards of 50% of the population can charge at home then that is a large proportion of private cars electrified, but agree, if the ban does go ahead it does mean there needs to be a solution when new car sales stop in 2030, and by 2040 you only have 10+yr old ICE cars as an alternative.

The others will have to be a mixture of off-street chargers, ability to lay cables across pavements using trenches, rapid charges and workplace charging.

When I owned my EV without a driveway for 2yrs I personally used 3 main ways to charge:

1. A local car pack with 4hours free parking in my town. I would charge once a week on a Sunday. Park up in the morning, go for my morning run/gym, then go home, later go do the shopping and drive the car back home.
2. Installed a charger at my parents, who I visited most weeks for family get togethers.
3. Workplace charging. I moved jobs and before COVID was expecting to travel 70miles/day. There were 6 chargers at my workplace that meant I could reliable charge at work every day to ensure I had enough to get there and back.

This all worked fine for me in my personal situation, but appreciate everyone is different.

I borrowed a Tesla for a few weeks and I can honestly say a trip to a supercharger made charging a non-issue, even if I didn't have home charging. Literally pull up, 12+ stalls all working, and done in 20mins. Getting the rest of the infrastructure to that level would do a lot to improve the situation.

Bachelorplace

I will add an element of context.

I also spent £13 on a burger and fries...at a venue I would not normally go to. In an ice, or with a much faster charger....!?

So that charge actually cost £22 plus £13 really. 

 a. Because I was tired b. Because I was stressed c. Because I was cold and wanted to go home. d. Because I wasn't going to sit in a cold car like a lemon for 57 minutes. 

My mum is not well and I was back and forth to hospital. EV in this instance even with home charging is properly useless, I am sorry to say.