Wondering how much it costs to charge an electric car? Wonder no more…
Electric cars bring with them many advantages, including reduced maintenance requirements and the fact they put out no on-road emissions, to the benefit of local air quality.
EVs have also historically been significantly cheaper to run than their petrol and diesel counterparts, but the recent spike in energy prices has unavoidably impacted the cost implicit in charging electric cars.
Here, we crunch the numbers to help you work out how much it costs to charge an electric car, both at home and when you’re on the road and reliant on public chargers.
How much does it cost to charge an electric car at home?
This will largely depend on the energy tariff you have at home and the size of the car’s batteries, but before we get onto some calculations, it’s worth highlighting that you’ll almost certainly want to get a home wallbox EV chargepoint installed at home.
Home wallbox costs
Domestic three-pin plugs are not recommended for charging EVs, partly because they will charge the car very slowly, and partly because the draw an electric car will put on the socket will be high, and so it is therefore not wise from a safety perspective. Three-pin plugs typically charge at around 2.3 kiloWatts (kW), so if your EV has a 100 kiloWatt hour battery, it will take 43.5 hours to charge from full to empty.
Fortunately, a number of companies build and fit home wallbox chargers, and these tend not to be prohibitively expensive, costing £800 or so. They’re also specifically designed to charge EVs safely, and can generally deliver electricity at up to 7kW, more than halving the time it will take to charge the car. You’ll need off-street parking to get a wallbox installed, though.
If you’re looking for an installer, carwow has teamed up with Rightcharge, our official EV charging installation partner. Rightcharge is the easy way to get a home charger installed for your new electric vehicle. They will recommend the right charger, match you with a trusted installer and help you find the best energy deal in a few simple steps. And in a special offer for carwow customers, Rightcharge is offering 250 FREE miles in the form of public charging credit, redeemable when your charge point is installed.
Energy tariff prices
A wallbox is a one-off cost, though, and your domestic energy prices will have a far greater bearing on how much it costs you to charge an EV at home.
EV battery sizes are measured in kiloWatt hours, or kWh, as is the electricity that is delivered to your home. A 100kWh battery will, clearly, take 100kWh of electricity to fill from 0-100%, and you can calculate how much this will cost by looking up how much you pay your electricity supplier for each kWh.
The energy price cap from April to September 2022 was £0.28 per kWh; at this price, a 100kWh EV would cost £28 to charge from 0-100%.
The price cap from October to December 2022 is £0.52 per kWh, and at this rate the same EV would cost £52. If your EV has a 50kWh battery you could halve these costs, whereas an 80kWh EV would be 80% of those prices (IE £22.40 at £0.28 per kWh; £41.60 at £0.52 per kWh).
Cost per mile is a more important metric
While the amount your energy provider charges per unit is clearly a hugely significant factor, it’s worth pointing out that the efficiency of an electric car is also important.
That 100kWh EV we modelled above will be able to store twice as much electricity as a car with a 50kWh. All other things being equal that would give it twice the range, but the reality is that most EVs with high-capacity batteries tend to weigh more than electric cars with smaller ones.
This tends to lead to smaller EVs being being able to travel further on a single kWh unit of electricity. As an example, a really efficient EV might cover five miles for every kWh of electricity its battery holds, whereas a less efficient one might only be able to go 2.5 miles per kWh. The more efficient EV will therefore cost you half as much per mile compared to the less efficient one, and so while the amount it will cost you to fill each car will differ, the amount each car will cost you to cover a mile is far more relevant.
An EV that does 2.5 miles per kWh and charged using electricity priced at at £0.52 per kWh will cost roughly £0.21 per mile.
An EV that manages 5 miles per kWh and charged using electricity priced at at £0.52 per kWh will cost roughly £0.10 per mile.
Let’s compare this to a petrol car, which might do 40 miles per gallon. With the average cost of a litre of unleaded (as of Sept. 22) being £1.64 (equivalent to £7.45 per gallon), each mile in that 40mpg car will cost £0.18.
Specialist home EV tariffs
The prices per kWh we’ve covered so far have assumed each unit costs the same as the energy price cap, but many electric-car owners get an electricity tariff that is specifically designed for EV drivers.
These tend to bring significantly lower prices at night, and with most EVs (and many home wallboxes) being able to schedule charging sessions based on owner preferences, it is easy to take advantage of these off-peak prices.
As an example, and while prices can vary based on region, Octopus Energy’s Go tariff costs £0.39 (rounded down – it’s really 39.34 pence) per kWh from the hours of 04:30 to 00:30, but from 00:30 to 04:30 it’s only £0.075 (7.5 pence) pence per kWh. On that tariff, a 100kWh EV would cost you £39.24 to charge during standard pricing hours, but if you schedule charging to take place between half midnight and half four in the morning, the same charge would only cost you £7.50.
If that EV covers 2.5 miles per kWh, each mile will cost you just 3 pence if charged at 7.5 pence per kWh, or 15.7 pence if charged at the higher rate.
How much does it cost to charge an electric car at a public charging point?
If you’ve made it through so far, the good news is things get a lot simpler from this point, because there are no wallboxes or variable tariffs to think about when it comes to public charging, while we’ve already covered most of the principles about EV charging and costs.
In short, the amount it costs to charge an electric car publicly depends on how large its battery is, and how expensive the electricity being sold by the chargepoint provider is.
Let’s start with the basics: public chargers are more expensive than home charging, and each network charges a different amount for their electricity, just as petrol stations set their own prices.
The Ionity network charges £0.69 per kWh, so a 100kWh EV would cost £69 to charge from full to empty, and a 50kWh EV would cost £34.50. A car that will cover five miles per kWh will cost 13.8 pence per mile if using Ionity, whereas an EV that does 2.5 miles per kWh will cost 27.6 pence.
Instavolt chargers all cost £0.66 per kWh, so the prices are very similar to the above.
Chargepoint firm Osprey recently (Sept ’22) announced its rapid chargers would cost £1 per kWh to reflect the energy crisis, so a 100kWh EV would cost £100 to charge from full to empty.
BP Pulse charges between £0.44 and £0.69 depending both on the speed of the charger being used, and whether you are a subscriber or a guest user.
Some public EV chargepoints are free to use, and these are often located at places such as supermarkets, gyms, hotels and the like. These tend to be slower 7kW chargers rather than the rapid 50-150kW units you’ll find at most public points you pay to use.
How much does it cost to charge an electric car on the motorway?
In the same way as filling up a petrol or diesel car will cost you more at a motorway service station, you may pay more to charge an EV there than you would at public points around town – though some chargepoint firms offer flat rates, no matter the location.
Motorway service stations tend to have a greater number of rapid chargers than other locations, so you’ll be able to get an impressive return on range for your money while you tuck into a coffee and a sandwich. Be mindful that some chargers and motorway-services car parks have time limits for use, with fines for those who outstay their welcome.
If you’ve got a Tesla, you’ll be able to use the company’s Supercharger network. This is gradually (and on a trial basis) being opened up to owners of other EVs, but in the main remains the preserve of Tesla Drivers.
Tesla Supercharges can be found at various locations, and are often situated at motorway services. They tend to be pretty fast, often with 150kW points that can take a battery from flat to full in about 40 minutes for the latest models.
Prices for Superchargers vary based on location and are displayed on the car’s touchscreen, so it’s worth checking before plugging in (though £0.67 per kWh is not atypical. Older models of Teslas came with free Supercharger use, although the manufacturer stopped offering this on cars made after 2016, limiting it instead to a set amount of mileage credits or hours of free charge annually.
You should also note Tesla charges idle fees if more than half the cabinets are in use and you’ve left a fully charged car plugged in.
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