It's one of the first things people worry about when switching to electric — and it's a fair question. The short answer is yes, your electricity bill will go up. But by how much depends almost entirely on how you charge, and for most drivers the increase is far smaller than the petrol saving it replaces.
How much electricity does an electric car actually use?
The average electric car uses around 3.5 miles per kWh of electricity — that's the standard UK efficiency figure across a typical mix of driving. At 10,000 miles per year, you'd use roughly 2,857 kWh to charge your car over 12 months.
To put that in context, the average UK household uses around 2,700–3,100 kWh per year for everything else — lights, appliances, heating. Adding an EV roughly doubles your household electricity consumption.
How much will it add to my electricity bill?
This is where the tariff you're on makes an enormous difference.
| Charging method | Rate | Annual cost (10k miles) | Monthly bill increase |
|---|---|---|---|
| Standard home rate | 24p/kWh | ~£685 | +£57/month |
| Economy 7 overnight | ~15p/kWh | ~£428 | +£36/month |
| Octopus Go overnight | 7p/kWh | ~£200 | +£17/month |
| Octopus Go (15k miles) | 7p/kWh | ~£300 | +£25/month |
On a standard tariff, adding an EV adds around £57 per month to your electricity bill. That sounds significant — until you compare it to what you were spending on petrol. At 10,000 miles a year in a 40MPG car at 169p/litre, you were spending around £57 per month on fuel anyway. So your bills swap — not stack.
Switch to a smart overnight tariff like Octopus Go and that drops to around £17 per month. Now you're saving roughly £40 per month compared to what you were spending on petrol.
💡 The single most important thing you can do: switch to a smart EV electricity tariff when you get your car. Octopus Go, EDF GoElectric and British Gas Electric Driver all offer cheap overnight rates specifically for EV charging. The difference between standard rate and smart tariff charging is worth £400–500 per year.
Will my supplier increase my bills because I have an EV?
No — your energy supplier has no way of knowing you have an electric car unless you tell them. They see increased electricity usage, but your unit rate stays the same. The only change is that you use more electricity, which you pay for at your existing rate.
In fact, switching to a smart EV tariff often means you get a lower rate overnight than you were paying before — the smart tariff charges are specifically designed to be cheap at night to encourage off-peak usage.
Does home charging affect my electricity meter?
It shows up as higher consumption on your meter — that's it. Some people worry about whether it affects standing charges or triggers any kind of tariff review. It doesn't. You simply use more kWh and pay for those units at your agreed rate.
If you're on a smart meter (most UK homes are now), you'll be able to see your EV charging usage separately in your supplier's app — which is a useful way to track costs.
What about solar panels?
If you have solar panels, the picture gets even better. A smart charger like the Ohme ePod or Hypervolt can be set to use surplus solar generation to charge your car first before drawing from the grid. On a good summer day, you might charge for free. Across a year, solar self-consumption can reduce your EV charging cost by 30–50% depending on your system size and usage patterns.
On a smart tariff, adding an EV costs around
£17 per month in extra electricity.
You were spending £57 per month on petrol.
How to minimise the increase in your electricity bill
- Switch to a smart EV tariff — Octopus Go, EDF GoElectric or British Gas Electric Driver. This is the biggest single lever.
- Charge overnight — between 11pm and 5am on most smart tariffs. A smart charger does this automatically.
- Use a smart charger — set a schedule once and it charges at the cheapest rate every night without you thinking about it.
- If you have solar, use solar divert — your charger uses surplus generation first.
- Don't charge to 100% every night — most EV manufacturers recommend keeping daily charging to 80% for battery longevity. It also means you use slightly less electricity.
Your bill goes up — but your total fuel spend goes down
Adding an EV will increase your electricity bill. On a standard tariff that's around £57 per month extra — roughly what you were spending on petrol anyway. On a smart overnight tariff it drops to around £17 per month, meaning you save around £40 per month compared to running a petrol car. The electricity bill increase is real, but it replaces petrol spending rather than adding to it — and on a smart tariff, you come out significantly ahead.
A smart charger makes the difference.
Our Ohme ePod automatically charges at the cheapest overnight rate — no scheduling needed. From £1,049 including installation across West Sussex, East Sussex and Surrey.
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