How much does your electric car add to your electricity bill?

[Bayum]

I’m seriously considering an electric car. I’m trying to find suggestions/ideas of how much it costs to charge overnight without any use of kwh and averages etc. but struggling to find any. Any ideas?

 

[fourtytwo]

There will be the hotel losses (what it uses standing around doing nothing) to replenish as well as the energy used in driving. The battery/charger of course are not 100% efficient so those losses have to be paid for as well. A very interesting question given the expected huge further rise in energy tariffs next year and something the manufacturers are very quiet about. Have you worked out how many miles you might do in a day ?

I suppose one might estimate the Kwh/mile by dividing the battery capacity by the claimed range but as we all know the range is somewhat questionable!

 

[Domh245]

It'll depend on your usage, both in terms of what car and how many miles - those are fundamental questions to get a reasonable idea. In the same way you don't ask "how much do you spend on petrol" without at least knowing a distance.

If we assume an average car with an efficiency of 3.5mi/kWh (~Mercedes EQA/MG 5 EV/Vauxhall Mokka E/Nissan Leaf are officially around this level, so reasonably representative) and you do 142 miles a week (UK average), and pay 23.6p/kWh for your electricity (the yorkshire region cap for standard meters), you'd pay about £9.60 a week.

The other way to look at it is the price to 'brim it' - for an MG 5 EV with a 61kWh battery, from empty to full you'd pay £14.50, for a mini electric with a battery that's around half the size you'd pay £7.70 for a full charge

 

[Bayum]

Work is about a 24 mile round trip 5x a week. Occasionally, I need to drive to and from Leeds which is 17 miles to Leeds and 13 miles home.

 

[Harpers Tate]

Assume the car will do around 4 miles per kWh. Varies by vehicle.
Typical week 5x24= 120 miles will use 30 kWh. And your extra trip is an extra 7.5kWh.
Assume charging efficiency around 80%.
You will need to feed the car about 38 kWh a week, plus 9.4 for the Leeds trip.
Multiply by your electric tariff: the current cap is just over 20p/unit so let's assume that what you pay. Whatever happens in the spring will affect that, of course.

38 x 20p = £7.60 normal week.
9.4 x 20p = £1.90 Leeds trip.

Now, if you can bear to spend a few hours shopping nearby where there is a supermarket with a free outlet, then you can currently reduce this.

 

[DelW]

There *have been* deals offering overnight charging at around 5p per kWh, which would mean costs about 1/4 of those above. However, with the present state of the energy market, it's anyone's guess when or if such deals might reappear. They certainly won't be available at present.

 

[skyhigh]

They certainly won't be available at present.

They're still available if you know where to look

 

[DelW]

They're still available if you know where to look

Oh, OK, so the OP might be able to get one and pay a much lower price than quoted above, if they're still available if/when they need it.

 

[skyhigh]

Oh, OK, so the OP might be able to get one and pay a much lower price than quoted above, if they're still available if/when they need it.

Octopus still offer it with their 'Go' tariff - however it's not shown on their online quote tool so you'll have to ask for it specifically to get it. You need to have an EV to go onto it now though.

 

[mmh]

The questions which nobody seems to have asked so far are to me the most relevant to making the decision

- are you going to buy a new car regardless
- why are you considering an electric car

Without knowing the answers to those it's pretty impossible to give any serious opinion.

 

[skyhigh]

The questions which nobody seems to have asked so far are to me the most relevant to making the decision

- are you going to buy a new car regardless
- why are you considering an electric car

Without knowing the answers to those it's pretty impossible to give any serious opinion.

To be fair the OP just asked the fairly simple question of 'how much does it cost', rather than opinions on if they should get one

 

[mmh]

To be fair the OP just asked the fairly simple question of 'how much does it cost', rather than opinions on if they should get one

My questions are far more relevant to how much it costs than many of the replies!

 

[Romsey]

A little warning about "cheap overnight charging" from personal experience. ( See the post by DelW above.) Mrs R is the proud owner her third Nissan Leaf anda while back wondered if there were any packages for cheap overnight charging and we found a couple. Both gave a very low rate per kwh overnight but for car charging only. The associated general tariff was getting on for double the discount rate we were paying to SSE. A scrap paper guestimation meant it was cheaper by staying our discount tariff. As Mrs R is working from home most of the time since March 2020, her car mileage has reduced by at least 50%.
On the general costs until early 2020 our electricity consumption had gone up by roughly £ 15 per month since owning an electric car. On the other hand we're not paying maybe £50 per month to oil companies and HMG.
To save money find out which supermarkets offer free charging. Sainsbury used to, but are in the process of appointing a new EV power supplier and provider of charging points. All four ev chargers at Winchester are OOS and apparently only one works at hedge End.

 

[NoRoute]

Both gave a very low rate per kwh overnight but for car charging only.

That is rather unusual though, most EV tariffs use your smart meter to measure your consumption, which measures how much the whole house is using but not how much the EV is using, with the off-peak rate applying to the whole house. I'm on an EV tariff and use the off-peak period for other things like running the dishwasher or the washing.

There are a few tariffs which provide a low rate for EV charging only, but these are normally sold as a package with a specialised EV charger which lets the supplier monitor exactly how much the charger has used. Personally I'd avoid these and stick with a simpler, whole-house type EV tariff.

 

[Bayum]

The questions which nobody seems to have asked so far are to me the most relevant to making the decision

- are you going to buy a new car regardless
- why are you considering an electric car

Without knowing the answers to those it's pretty impossible to give any serious opinion.

I’d be looking at a new car this year, yes. I’m considering an electric car to try and reduce fuel costs and environmental concerns. Fuel is one of my main outgoings and if I can reduce that and pay more at home for electricity to help out mum the that’d be great.

 

[kevin_roche]

I have a Toyota Prius Plug In. I know it's not completely electric but it allows me to compare its Hybrid performance with electric performance so the information may be useful. It does about 50mpg when on petrol.

During the last couple of years, with lockdowns etc I have not actually put petrol in it as often as it mostly gets me where I want to go on electricity alone.

I worked out the cost per mile a little while ago relying on charging at home with cost about 13p per kWh and running on electric was 6p per mile and petrol was 12p a mile. Both have gone up since so it may be slightly more now.

I recently had a mail from one of the charging companies saying they were going to be charging 40p per kWh and it seems to me that will mean it is cheaper to put petrol in.

 

[EveningStar]

Two electric cars in household since October and not due to change tariff until next month. Electric bill settled down at £25/month extra against previous total petrol costs of ~£250/month. Factor into that extra over for higher purchase cost, less tax and insurance costs (Mrs ES went up, mine went down ... go figure). I get free charging at work, although pressure on a small number of charging points so not a given on any individual day. Overall costs come about about same as before.

Only real world point is that quoted values for range are as cloud-cuckoo as manufacturers stated MPG ... always knew I had an indelicate right foot.

 

[DelW]

Only real world point is that quoted values for range are as cloud-cuckoo as manufacturers stated MPG ... always knew I had an indelicate right foot.

This point isn't specifically aimed at you, but was prompted by your last comment.

People don't always realise that with EVs, heating the car interior is no longer done at zero cost, unlike with IC engines.

With ICEs, heat which would otherwise be dumped into the atmosphere via the radiator is instead directed into the cabin via the heater matrix. With an EV, there is no "spare" heat, so heating is done electrically, and just like running a fan heater indoors, there's a cost to that.

I'm not suggesting that we should go back to the days of dressing up in overcoats, scarves and gloves to go out in the car, but if you have an EV (or most PHEVs I think), and you don't actually need the heater on, you can get a small but still noticeable increase in range by turning it down or fully off.

 

[Bletchleyite]

I'm slightly surprised that other options for heating than battery-electric aren't looked at. For buses it seems to be diesel heaters which is a bit ironic, but would not some sort of storage heater be worthy of consideration, with the option to top up from the battery? If most people plug in overnight that could be warmed up then.

 

[kevin_roche]

I'm not suggesting that we should go back to the days of dressing up in overcoats, scarves and gloves to go out in the car, but if you have an EV (or most PHEVs I think), and you don't actually need the heater on, you can get a small but still noticeable increase in range by turning it down or fully off.

Yes, it is noticeable in my Toyota Prius plug-in. In the winter I have found that going to work in the morning when it is colder it's better to use the ICE and come home on the battery when the temperature has warmed up a bit as I can usually come home without heating.

== Doublepost prevention - post automatically merged: 15 Dec 2021 ==

I'm slightly surprised that other options for heating than battery-electric aren't looked at. For buses it seems to be diesel heaters which is a bit ironic, but would not some sort of storage heater be worthy of consideration, with the option to top up from the battery? If most people plug in overnight that could be warmed up then.

I actually plug in a 240v fan heater to warm the car on icy mornings before I leave home.

 

[Bletchleyite]

I actually plug in a 240v fan heater to warm the car on icy mornings before I leave home.

If the car is on charge I'm surprised they don't allow you to programme it to run the car's heater off the mains at a set time to be ready. I expect some do.

 

[Harpers Tate]

.....With an EV, there is no "spare" heat, so heating is done electrically, and just like running a fan heater indoors, there's a cost to that.

I'm not suggesting that we should go back to the days of dressing up in overcoats, scarves and gloves to go out in the car, but if you have an EV (or most PHEVs I think), and you don't actually need the heater on, you can get a small but still noticeable increase in range by turning it down or fully off.

Indeed. Although in some better-equipped models, the heater is an air source heat pump which uses ~25% the power of an equivalent conventional heater. And if you have heated seats and steering wheel (as I do) then, used instead of cabin heat in marginally cold weather these consume way less again.

If the car is on charge I'm surprised they don't allow you to programme it to run the car's heater off the mains at a set time to be ready. I expect some do.

Mine can be scheduled to pre-heat (or cool) the interior when it's connected to a charger.

 

[DelW]

If the car is on charge I'm surprised they don't allow you to programme it to run the car's heater off the mains at a set time to be ready. I expect some do.

My PHEV allows that (heating in winter, a/c in summer) by pre-setting a departure time. I think you can also use a phone app to turn it on, though I've never investigated that.

I wish I'd had that option when I was still working, and leaving home at 06:30 on frosty winter mornings.

 

[py_megapixel]

I'm slightly surprised that other options for heating than battery-electric aren't looked at.

I'm yet to see an EV which does not come with air conditioning, so I assume most of them are capable of using their air conditioning equipment in reverse to heat the car (i.e. operating as an air-sourced heat pump) - which is considerably more efficient than a normal electric heater. Or am I being too optimistic there?

== Doublepost prevention - post automatically merged: 15 Dec 2021 ==

People don't always realise that with EVs, heating the car interior is no longer done at zero cost, unlike with IC engines. With ICEs, heat which would otherwise be dumped into the atmosphere via the radiator is instead directed into the cabin via the heater matrix. With an EV, there is no "spare" heat, so heating is done electrically, and just like running a fan heater indoors, there's a cost to that.

I'm not sure that's actually true with more modern ICE vehicles. In my car, the heat comes on suspiciously quickly after starting from cold - I think there must be an electric heating element in the system somewhere, even if the computer disables it once the engine is warm.

Compare that to another car in my family, about 15-16 years old - the heat doesn't start for quite a number of minutes.

I actually plug in a 240v fan heater to warm the car on icy mornings before I leave home.

Does your car have a 240V socket (which I think is quite unusual on vehicles)? Because otherwise you presumably have to leave a car window open to run a cable through, which means your little fan-heater is heating the icy cold air outside, hugely reducing the efficiency.

 

[DelW]

I'm yet to see an EV which does not come with air conditioning, so I assume most of them are capable of using their air conditioning equipment in reverse to heat the car (i.e. operating as an air-sourced heat pump) - which is considerably more efficient than a normal electric heater. Or am I being too optimistic there?

You may well be right, I know it's electrically powered on mine but I don't know exactly how. Turning the heater off definitely increases predicted electric range though.

I'm not sure that's actually true with more modern ICE vehicles. In my car, the heat comes on suspiciously quickly after starting from cold - I think there must be an electric heating element in the system somewhere, even if the computer disables it once the engine is warm.

Compare that to another car in my family, about 15-16 years old - the heat doesn't start for quite a number of minutes.

My last car was a diesel Focus from 2012, and on winter mornings it took a good 10 minutes driving before any warmth appeared. An earlier electric boost would have been very welcome!

 

[Domh245]

I'm yet to see an EV which does not come with air conditioning, so I assume most of them are capable of using their air conditioning equipment in reverse to heat the car (i.e. operating as an air-sourced heat pump) - which is considerably more efficient than a normal electric heater. Or am I being too optimistic there?

As @Harpers Tate notes, Heat pump for heat is a rare feature - not only does it require the immense cost & complexity (/s) of a reversing valve but they are also subject to the usual heat pump compromises around how the heat is delivered.

I'm not sure that's actually true with more modern ICE vehicles. In my car, the heat comes on suspiciously quickly after starting from cold - I think there must be an electric heating element in the system somewhere, even if the computer disables it once the engine is warm.

Compare that to another car in my family, about 15-16 years old - the heat doesn't start for quite a number of minutes.

Some cars will come with a small electric heater to help deliver heat more quickly, but some manufacturers have also taken to engine cooling systems designed for rapid warmup though I get the impression this was done more with emissions in mind than passenger comfort

The experience I've had with my parent's outlander is that it is the fan motor that is the big energy consumer, with heating/cooling only having a small impact beyond that.

 

[AM9]

Do any current EVs that have a battery temperature management system use the heat given off when driven to heat the vehicle? Even better would be to capture the heat created in the battery when being charged.

 

[JohnMcL7]

I'm not sure that's actually true with more modern ICE vehicles. In my car, the heat comes on suspiciously quickly after starting from cold - I think there must be an electric heating element in the system somewhere, even if the computer disables it once the engine is warm.

Compare that to another car in my family, about 15-16 years old - the heat doesn't start for quite a number of minutes.

I've found the engine type can make a big difference, my current petrol car has no electric heater but it produces heat almost straight away same as the other petrol car in the household but the diesel one took a frustratingly long time to heat up, noticeably worse than the diesel before which I assume is due to the efficiency of the newer engine. Irritatingly the diesel (Skoda Octavia) did offer a factory fit ceramic heater but not in the UK only the colder climates despite the fact it would have definitely been useful here.

 

[david1212]

...
If we assume an average car with an efficiency of 3.5mi/kWh (~Mercedes EQA/MG 5 EV/Vauxhall Mokka E/Nissan Leaf are officially around this level, so reasonably representative) ....

Assume the car will do around 4 miles per kWh. Varies by vehicle.
....

Of course it depends numerous factors including journeys, driving style and congestion but if those consumption figures are on a test track they will be optimistic in the real world.

As an example look at the Vauxhall E-Mokka website page

At 40mph the range at 15degC with climate control on is is 207 mile so just over 4mi/kWh. That presumably is a constant speed not real world in a 40mph zone slowing for and accelerating from junctions. At ( a constant ? ) 60mph down to 157 miles so just over 3mi/kWh and at 70mph 125 miles so 2.5mi/kWh.

I would not work on anything better than 3mi/kWh. If your consumption was less consider it a bonus.

Further while directly OT for the government to recover a similar income to fuel duty & VAT @ 20% rather than 5% they will need an average of around 7.5 p/mile. Road fund licence will either get lumped in with this at 1.5 p/mile based on an average of 10,000 miles per year or be charged at the current rates for petrol & diesel cars. Hence overall compared to now the running cost realistically will increase by around £900 for 10,000 miles per year.

 

[AM9]

Of course it depends numerous factors including journeys, driving style and congestion but if those consumption figures are on a test track they will be optimistic in the real world.

As an example look at the Vauxhall E-Mokka website page

At 40mph the range at 15degC with climate control on is is 207 mile so just over 4mi/kWh. That presumably is a constant speed not real world in a 40mph zone slowing for and accelerating from junctions. At ( a constant ? ) 60mph down to 157 miles so just over 3mi/kWh and at 70mph 125 miles so 2.5mi/kWh.

I would not work on anything better than 3mi/kWh. If your consumption was less consider it a bonus.

It's wrong to assume that normal stop start driving in built-up areas increases energy consumption over steady c 50mph cruising. On ICVs, that presumption is based on the engine running at a steady speed at or near its most efficient level, pitched against a start stop usage where all of the energy used to accelerate is dumped into heat in the brakes or stirring the engine in overrun. With EVs, much of that energy invested in accelerating will be recovered by regeneration and returned to the battery. That is why EVs give a double benefit in urban areas

== Doublepost prevention - post automatically merged: 16 Dec 2021 ==

... Further while directly OT for the government to recover a similar income to fuel duty & VAT @ 20% rather than 5% they will need an average of around 7.5 p/mile. Road fund licence will either get lumped in with this at 1.5 p/mile based on an average of 10,000 miles per year or be charged at the current rates for petrol & diesel cars. Hence overall compared to now the running cost realistically will increase by around £900 for 10,000 miles per year.

The government won't need to consider most of the peripheral environmental and health damage that ICVs cause which is the major justification for the Vehicle Excise Duty. There hasn't been a "road fund licence" since 1937! Roads are funded through general taxation which will continue, with the residual cost of EV pollution being recovered by a new road charging scheme where costs are related to usage.