The car
A Skoda Enyaq arrived in July 2026 and is now the only car on the drive. It replaced two: a petrol Nissan Qashqai 1.6 and a diesel Citroen C4, which did roughly half the mileage each. It's the biggest new electricity load the house has had, and also one of the biggest savings on this site. This page treats those as two separate things.
Modelled, not measured. The car isn't metered separately from the house, so mileage, efficiency and charging losses here are estimates. The fuel figures use the economy we actually got from the two cars (not the manufacturer figures) at UK average pump prices in September 2026. We'll replace them with real figures after a full year of charging.
Driven
10kmi/yrat 3.4 mi/kWh
Electricity used
3,268kWhoff the meter, incl. charging losses
Fuel it replaces
£1,822/yrtwo cars, blended 18.2p a mile
Saving
£1,573/yr18.2p a mile down to 2.49p
What a mile costs
The Qashqai's 1.6 petrol managed about 36 mpg in real use, which at 167p a litre is 21.1p a mile. The C4 diesel did much better at 56 mpg, but diesel is the dearer fuel now at 189p, so it still cost 15.3p. The Enyaq, charged overnight, costs 2.49p.
Pence per mile. Even charged in the middle of a weekday at the full day rate, the Enyaq is cheaper to run than the diesel was, and half the cost of the petrol.
How much of this is the solar?
Very little. Most of the saving comes from the car being electric. Anyone with a driveway and a cheap overnight tariff would get most of it without any solar panels at all.
We've left this saving out of the solar payback. The payback tracker compares the panels and battery against what the same electricity would have cost without them. Adding £1,573 of avoided fuel would make the solar look as if it paid back in half the time. That wouldn't be fair, because we'd have saved most of it by buying the same car and plugging it in at an ordinary house, so the two are counted separately.
What if fuel prices change?
Our electricity price is fixed for twelve months, but pump prices aren't. Diesel is already about 189p and edging towards £2. The old fuel bill goes up with it and the charging bill stays where it is.
| 10,000 miles | today | +10% | +20% |
|---|---|---|---|
| All miles in the Qashqai | £2,109 | £2,320 | £2,531 |
| All miles in the C4 | £1,534 | £1,688 | £1,841 |
| Our actual 50/50 split | £1,822 | £2,004 | £2,186 |
Against £249 of electricity, every cell in that table is a saving of between £1,285 and £2,282 a year. The electric car is cheaper at today's fuel prices, and the gap only widens if they rise.
Why we don't charge it from the solar
Until 22 September the car charged from surplus solar on a granny lead. With export unpaid, that was the right call: a spare kWh was worth nothing unless we used it, and every unit that went into the car instead of the grid saved the full import price.
Now that export pays, we do the opposite. Exported solar earns 12p and the overnight rate is 8p, so it's cheaper to export the solar and charge the car overnight, and we keep the difference on every kWh the car takes. Not charging the car from your own panels feels odd, so we've written it down here before we get into the habit. See the tariff.
Winter will be tighter
The car adds about 3,268 kWh a year to a house that generates about 9,900. In summer that makes little difference. From December the heat pump will be using the same six-hour cheap window, so the battery, the car and the heating will all be competing for the same hours. That's mainly a scheduling problem for Predbat to handle, and we'll publish how it gets on.
Charging an EV at home?
Octopus · we both get £50
Most of the saving above comes from the overnight rate. The site has no sponsors, and you get the same referral payment we do.
Claim £50 share.octopus.energy/lush-spark-49