Is an Electric Car Still Cheaper to Run If You Can't Charge at Home?
Is an Electric Car Still Cheaper to Run If You Can't Charge at Home?
Going Green — by Philip M Russell
Two people can drive the same electric car and pay very different amounts to keep it moving.
One plugs in on the driveway and lets an overnight tariff do the work. The other lives in a flat, parks on the street and relies on public chargers.
Same car. Same distance. Very different electricity bills.
That matters whenever an advertisement promises motoring for a few pence per mile. The calculation may be perfectly valid for someone with a suitable home charger and tariff. It may tell you very little about the cost of using the same car from a terraced house without off-street parking.
An electric car can still be cheaper on energy without home charging. But the advantage depends on the public prices you can actually access, the car's efficiency and the petrol or diesel vehicle you are comparing it with.
The useful starting point is a practical question: what would 100 miles cost me?
The Price at the Plug Changes Everything
Electricity is sold in kilowatt-hours, shortened to kWh. For our purposes, that is the quantity of energy you buy. A charger's power rating in kW tells you about charging speed; its price per kWh tells you about energy cost.
Public charging does not have one national price.
Zapmap's October 2026 index, updated on 5 November, reports weighted average pay-as-you-go prices of 54p/kWh for standard and standard-plus public chargers, and 82p/kWh for rapid and ultra-rapid chargers. Individual sites, memberships and promotions can differ substantially. These are market reference points, rather than quotes for your local charger. [1]
At home, Ofgem's October–December 2026 average electricity unit rate for customers paying by Direct Debit is 26.32p/kWh across Great Britain. Your region and tariff may differ. [2]
Specialist EV tariffs can be considerably cheaper during qualifying periods. At the time of checking, Intelligent Octopus Go advertises eligible smart charging from 6.5p/kWh, subject to its requirements and terms. That is an example of a conditional tariff, not a price every household can obtain. [3]
Already, we have the explanation for those apparently contradictory conversations about electric motoring.
Both drivers may be reporting their costs accurately. They are buying energy at very different prices.
First, Include the Electricity That Does Not Move the Car
Suppose our example EV achieves:
4 miles per kWh of energy used from the battery.
It therefore needs:
100 / 4 = 25 kWh from the battery to travel 100 miles.
However, the electricity paid for and the energy subsequently available for driving are not necessarily identical. Charging involves losses and auxiliary energy use. ADAC's measurements show that these depend on the vehicle and charging conditions, including the distinction between AC and DC charging. [4]
For the worked examples below, assume 90% efficiency between billed electricity and usable battery energy:
Electricity bought = 25 / 0.90 = 27.78 kWh.
This is a transparent modelling assumption, not a claim that every charger loses exactly 10%. In particular, some conversion losses at a DC charging station occur upstream of the meter used to bill the driver. Only count the losses between the energy you pay for and the energy used by the car.
If a published consumption figure already includes charging losses, do not add them again.
The most useful real-world check is to record billed kWh and miles over several charges, beginning and ending at roughly the same battery charge level.
What Would 100 Miles Cost?
The following comparison uses the same EV, the same 4 miles/kWh and the same assumed 90% charging efficiency throughout.
| Charging option | Price per kWh | Energy cost per 100 miles | Energy cost per mile |
|---|---|---|---|
| Eligible home smart charging example | 6.5p | £1.81 | 1.81p |
| Home electricity at the stated Ofgem average | 26.32p | £7.31 | 7.31p |
| Public charger: illustrative local price | 45p | £12.50 | 12.50p |
| Standard public charging at the cited average | 54p | £15.00 | 15.00p |
| Public charger: illustrative higher price | 65p | £18.06 | 18.06p |
| Rapid public charging at the cited average | 82p | £22.78 | 22.78p |
Calculations by the author. The 45p and 65p rates are hypothetical comparison points, not advertised offers. Energy only: parking, subscriptions and other fees are excluded. All results are rounded.
At the two ends of this example, the electricity bill differs by more than a factor of twelve.
That does not mean every home-charging driver gets the lowest price, or every public-charging driver pays the highest. It does mean that quoting an EV running cost without explaining the charging arrangement leaves out a crucial part of the story.
Compare It With Your Actual Petrol Car
Let us compare the EV with a petrol car achieving 45 miles per UK gallon, with petrol at an illustrative £1.70 per litre.
This is a worked assumption, not a claim about today's national average. Use the price at your own filling station and the consumption you actually achieve. The government's weekly fuel-price series offers a useful national reference. [5]
One UK gallon is approximately 4.546 litres.
Litres needed for 100 miles = (100 / 45) x 4.546 = 10.10 litres.
Cost of 100 miles = 10.10 x £1.70 = approximately £17.17.
Against this particular petrol car:
- EV charging at 45p/kWh costs £12.50 per 100 miles.
- EV charging at 54p/kWh costs £15.00 per 100 miles.
- EV charging at 65p/kWh costs £18.06 per 100 miles.
- EV charging at 82p/kWh costs £22.78 per 100 miles.
Public charging can therefore produce a saving or an extra cost.
A more economical petrol hybrid would make the EV comparison tougher. A less economical petrol car would make it easier. For diesel, use the same calculation with your own diesel price and UK mpg.
Comparing a small electric hatchback with a large petrol SUV tells us less than comparing vehicles that perform a similar job.
Find Your Break-Even Electricity Price
Our example EV buys 27.78 kWh for 100 miles. Our example petrol car spends £17.17 covering the same distance.
The electricity price at which their energy costs match is:
Break-even electricity price = petrol cost per 100 miles / billed EV kWh per 100 miles.
Using unrounded figures, the answer is approximately:
61.8p/kWh.
Below that price, the example EV has the lower energy bill. Above it, the example petrol car does.
This threshold belongs to these assumptions. If the EV's efficiency, the petrol car's mpg or the pump price changes, so does the answer.
For someone without a driveway, this can be a more useful number than a national average. You can compare it with the actual prices on chargers near home, work and regular destinations.
A Charging Routine Matters More Than One Expensive Stop
An occasional costly motorway charge does not determine your whole year's motoring bill.
Equally, finding a cheap charger once does not make it the price you will pay all year.
Imagine someone without home charging buys:
- 70% of their electricity at 45p/kWh near work;
- 30% at 82p/kWh on journeys.
Their weighted average is:
(0.70 x 45p) + (0.30 x 82p) = 56.1p/kWh.
For our example car, that means approximately £15.58 per 100 miles.
That remains below the example petrol cost, although the saving is modest.
Weight the prices by the kWh bought, rather than the number of charging sessions. A short top-up and a substantial recharge should not have equal influence on the average.
Before buying a car, try mapping an ordinary fortnight. Where would charging fit naturally? Would the car charge while you work, shop or exercise? Is there a realistic alternative if the usual charger is occupied?
A cheap charger is useful when it is available at the times you need it.
Read Beyond the Headline Tariff
At home, compare the whole household bill
A low overnight price needs to be considered alongside the daytime rate, standing charge, eligibility requirements and the amount of charging that fits into the cheap period.
If switching tariffs raises the cost of the electricity used by the rest of the house, include that difference.
Do not assign the entire existing household standing charge to the car. Count additional costs caused by the change, including charger installation where relevant.
With solar panels and batteries at home, I am particularly interested in where each kWh goes. Electricity used for a car could sometimes have been exported or used elsewhere in the house. That gives it an opportunity cost, even when there is no immediate import bill.
It is worth doing the calculation rather than simply calling solar charging “free”.
In public, compare the complete charging session
Check the price through the payment method you intend to use. App, contactless, roaming and membership prices may differ.
Also check for:
- separate parking charges;
- connection or minimum fees;
- idle or overstay charges;
- time limits and access restrictions;
- subscription fees and cancellation terms.
These are checks to make at the particular site, rather than charges that every operator applies.
Suppose a hypothetical membership costs £10 a month and reduces charging by 10p/kWh:
Monthly break-even use = £10 / £0.10 = 100 kWh.
Above 100 kWh a month on that network, the discount exceeds the subscription cost. Below it, pay-as-you-go would cost less under those terms.
Only count electricity you would realistically buy there.
A £3 parking fee also matters. If a 20 kWh charge costs £10.80 at 54p/kWh, adding £3 makes the session £13.80: an effective 69p per billed kWh.
If you would have paid to park there anyway, only the extra parking expense belongs in the charging comparison.
Winter Can Change the Answer
A car's efficiency is a variable, not a permanent promise.
For planning, test what happens if your EV achieves 3 miles/kWh rather than 4. This is a sensitivity calculation, not a forecast for every winter journey.
At 90% charging efficiency, it would require:
100 / 3 / 0.90 = 37.04 billed kWh per 100 miles.
At 54p/kWh, the cost becomes £20 per 100 miles, compared with £15 in the earlier example.
That is enough to reverse the energy-cost result against our £17.17 petrol benchmark.
The sensible response is to use consumption figures suited to your journeys and repeat the calculation for less favourable conditions. Petrol and diesel consumption varies too; use comparable conditions on both sides.
If you tow a boat or trailer, include those journeys in your assessment rather than relying only on an unladen average.
Annual Mileage Makes Small Differences Add Up
Here is what our original EV example costs at three annual mileages:
| Annual mileage | All at 6.5p/kWh | All at 54p/kWh | All at 82p/kWh |
|---|---|---|---|
| 5,000 miles | £90 | £750 | £1,139 |
| 10,000 miles | £181 | £1,500 | £2,278 |
| 15,000 miles | £271 | £2,250 | £3,417 |
Illustrative annual energy costs, retaining 4 miles/kWh and 90% charging efficiency. Prices and efficiency are held constant for comparison.
At 10,000 miles, our example petrol car would use about £1,717 of fuel.
Charging the EV entirely at 54p/kWh therefore saves around £217 a year on energy. Charging entirely at 82p/kWh costs around £560 more.
Those figures are far less dramatic than the comparison with cheap home charging. They also show why annual mileage matters: a small saving per mile needs sufficient mileage to become a substantial annual saving.
Depreciation Can Outweigh the Charging Saving
“Cheaper to charge” and “cheaper to own” answer different questions.
Consider two hypothetical cars bought for £20,000:
| Three-year ownership example | Electric car | Petrol car |
|---|---|---|
| Purchase price | £20,000 | £20,000 |
| Assumed resale value after three years | £11,000 | £13,000 |
| Depreciation | £9,000 | £7,000 |
These are invented figures to demonstrate the calculation, not forecasts for either market.
The EV loses £2,000 more in value in this scenario. An energy saving of about £217 a year totals only about £651 over three years, so it would not cover that depreciation difference.
Different purchase prices or resale values could reverse the result. A used EV bought at an attractive price needs its own calculation.
Include insurance quotes, servicing, repairs, tyres, vehicle tax, finance interest and any charger installation or subscription costs. Use figures for the actual vehicles being considered.
For a car you buy, count purchase price minus resale value as depreciation; do not also add the entire purchase price as another cost. For a lease, compare the initial payment, rentals and relevant charges instead of adding depreciation separately.
If the real decision is whether to keep a serviceable car or replace it, compare those two options. A new-car-versus-new-car comparison may not answer your question.
My View: Start With the Driveway—or the Lack of One
In Going Green, I want to look beyond a headline saving and ask whether it survives contact with everyday life.
A household with solar panels, battery storage and somewhere to charge has options that someone in a flat may not have. It would be unfair to present the first household's costs as though everyone can reproduce them.
It would also be a mistake to assume that everyone without home charging faces the same expensive routine. A suitable workplace charger or competitively priced local site can change the calculation.
The financial result does not settle every environmental question. For this article, the aim is narrower and practical: establish what the motoring would cost, using access and prices that belong to you.
Your Challenge: Calculate the Cost of Your Next 100 Miles
You do not need a complicated spreadsheet. Gather four things:
- A realistic efficiency figure for the EV.
- Prices at the chargers you can regularly use.
- An allowance for charging losses, unless already included.
- Your current car's real mpg and local fuel price.
Then calculate:
EV billed kWh per 100 miles = 100 / miles per kWh / charging efficiency.
Use 0.90 for an assumed 90% efficiency.
EV cost per 100 miles = billed kWh x electricity price in pounds + allocated extra fees.
For petrol or diesel:
Cost per 100 miles = (100 / UK mpg) x 4.546 x fuel price per litre.
For a mixed charging routine, work out the average electricity price using your expected share of kWh at each location. Spread monthly fees across the miles driven that month.
Finally:
Annual energy-cost difference = difference per 100 miles x annual mileage / 100.
Write down one ordinary scenario and one less favourable scenario. Then add the ownership costs before deciding whether changing cars would save money.
The Right Answer Starts With Your Available Charger
Is an electric car still cheaper to run if you cannot charge at home?
It can be—but it is a calculation to make, rather than a saving to assume.
Cheap domestic electricity can create a substantial advantage. Public charging can still be competitive, but higher prices, extra fees or lower efficiency can reduce that advantage or reverse it. Depreciation can then change the ownership result again.
Before accepting a claim about pennies per mile, find out where those pennies come from.
Look up the chargers you could actually use. Calculate 100 miles. Then ask what a year—and three years—would cost.
That is how an interesting advertisement becomes an informed decision.
Sources and Price Note
Prices checked on 5 November 2026. Tariffs change; check live prices before relying on an example. All calculations and hypothetical ownership scenarios are the author's. The uniform 90% charging-efficiency assumption is for comparison and should be replaced with suitable measured data where available.
[1] Zapmap Price Index, updated 5 November 2026; October 2026 public PAYG averages.
[2] Ofgem: energy price cap unit rates and standing charges, October–December 2026.
[3] Octopus Energy: Intelligent Octopus Go, advertised rates and eligibility checked 5 November 2026.
[4] ADAC: charging losses in electric cars, measurements and explanation of AC and DC losses.
[5] Department for Energy Security and Net Zero: weekly road fuel prices. Use this for a national reference, or use your local pump price. The £1.70/litre used above is illustrative.
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