Electric vehicles

You may already drive an electric car. At 20% of the UK new car market, they're a lot more common than Net Zero Homes! If you do, that's great, they are one of the critical techs for a sustainable future. Ignore any of the propaganda you may see about EV problems, even that they're not really green - this is all wrong or fake - see this car industry mythbuster for a start.

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If you don't yet drive an EV, you might be wondering how much of a priority an EV is. Should you put your money there, or into the core net zero techs we feature elsewhere on this site: PV, heat pump or battery. After all, even a second hand EV could easily cost £20,000, and this money could equally pay for ALL these home techs instead!

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In fact we don't think the decision is like that. The first and simple point is, do you really need a car? If you do, it's not an alternative to net zero home tech, it's a vital tool you will own already, whether EV or ICE (Internal Combustion Engine). Used EVs have roughly reached price parity with conventional ICE cars, so it's not an extra cost - in fact, you will probably save enormously on fuel costs, because home EV charging is around 1/10 of the cost of petrol or diesel. So you can treat it as a separate decision and get an EV next time you need to change your car.

If you don't need a car, or not badly, then consider having no car, or one less. If you live in a city, using a car club is a great alternative. We used to do this, and reckoned it was cheaper than owning a car, so long as you didn't need a car more than 100 days a year.

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The only reasons not to get an electric car

There are really only three:

1. I don't need a car! In green terms no car at all is the best option, if you can manage it. If you live in a place with good public transport or a Car Club, or can borrow a car, then why bother with the expense and occasional hassle (parking, security)? With so many delivery services and the ubiquitous Uber, a car is optional for many. Nearly 1/4 of UK households don't have a car, rising to nearly half in London.

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2. They're still too expensive for me. Electric cars are newer cars, and this makes them more expensive. If you're used to buying and running cars 5-10 years old (which is a very cost-effective approach), then you may need to wait a few years before you have a good choice at this price point.

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3. I don't have off-street parking. This affects around 35% of UK households, and is the single biggest obstacle to buying an EV. It makes it much harder to make use of cheap home charging. You can use public chargers for sure, but this will cost nearly as much as petrol or diesel, which is offputting. Many local authorities are installing street chargers eg in lamp posts, but you don't have the same guaranteed cheap access as home charging. There are other solutions but really we need a nationwide legal framework on how to do this.

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How does an electric car integrate with the Net Zero Home?

Can it be "Net Zero Home & Car"?

When you get an electric car, and charge it at home, you are effectively just adding a large new appliance. It will probably use less electricity than your heat pump, but more than anything else you own, unless you have something like a hot tub or swimming pool. At average mileage mostly charged at home, it will use about 1,500kWh per year, vs maybe 2,500kWh for a heat pump (again average heating demand), and 2,500kWh for other house needs. So it's a significant extra, adding maybe 15% to your electricity consumption. (of course, you stop spending £700 or more a year on fossil fuels, but these were previously outside the scope that we discuss elsewhere for the net zero home). 

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To be "Net Zero Home & Car", or as close to it as possible, you will therefore need to generate more solar than you would have otherwise. 1,500kWh per year can be generated by 1500kW of solar, or about 4 extra panels. Yes, that's all it takes to feed an average mileage EV! This is what you need to maintain net zero carbon for home & car.

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Net zero cost for your home & car!

​Strangely, achieving net zero cost is far easier! This is because there are some truly amazing tariffs out there for EVs, which can mean that average mileage may only cost you £100 per year to run your car! And to think you once you used to spend nearly that on a single tank fill! This cost is so low that it's within the year to year variability that you will experience in your home, as hot or cold weather and solar variation changes your production and consumption.  Whether or not you remain technically net zero cost with your electricity, you will be quids in overall due to not spending on fossil fuel. (note that you will probably use public chargers sometimes too. While some of these are as expensive as fossil fuel, they are like restaurants in that you only use them on special occasions).

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Minimising your vehicle energy costs

There are two factors: how much power the car uses, and what you pay for it.

Vehicle efficiency

So pay attention to efficiency when you buy your EV. Just as with ICE cars, efficiency can vary by a factor of two between big heavy SUV type EVs, and smaller lighter weight ones. A good resource to check this out in Europe is the EV database. You can filter & sort by obvious factors like price and range, but also efficiency, measured in Wh/mile. In 2025 the most efficient cars included the Tesla Model 3, Mini Cooper E, Hyundai Ioniq 6, and Dacia Spring 45, all with around 150Wh/mile (as with fossil, real life consumption is likely to be higher - we get around 200Wh/mile). Meanwhile big heavy vehicles like the Audi e-tron might be closer to 300Wh/mile. Obviously, the less the car uses, the less you have to put into it to recharge.

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EV tariffs

This bit is vital. If you use a standard tariff, you will pay 25/kWh, or maybe 5p/mile. But with the best EV tariff you pay just 7p/kWh, or less than a third. EV tariffs are this cheap because they are Time of Use tariffs - see our section on smart tariffs for an explanation of this. The most popular smart EV tariff is Intelligent Octopus Go. This charges just 7p/kWh, so long as you normally charge between 2330 and 0530 the following morning. Not just this, but the clever smart technology will actually choose when to charge your car, and turn on and off the charging for you - you just need to plug it in. If you need more charging than there is time available in that slot, they will normally extend it for you automatically so that your car reaches your set charge level by the time you need it. And when your car is smart charging, your whole house benefits from the 7p tariff. This means that we run the heat pump much more enthusiastically at night than we used to, because you're essentially banking really cheap heat in the house!