Despite the standard variable electricity price increasing to 28p/kWh there are some deals out there for EV users – some as low as 4.5p/kWh and this is one of the main attractions on moving to an EV. But beware the cost of your day rate..
Speed, A/C and DC
Charge is measured in kilowatts (kW). The higher the kW the faster the charge.
Alternating current (AC) is what you get from the mains at home. EV internal charging systems tend to be able only to take up to 22kW on A/C.
Public rapid chargers are direct current (DC) and can go far higher – up to 150kW and more.
• A 3-pin ‘Granny charger’ plugged into the mains will give 9-10 miles per hour
• 7.5kW will give up to 35 miles of charge per hour
• 22kW, 60 miles of charge per hour
• 50kW, 180 miles
• 150kW, 400 miles per hour
A charger of more than 7.5kW will slow down to a trickle charge at 80%. If you’re on a public charger the queue behind could get a bit twitchy!
As of July 2022, the UK government will mandate that all home chargers must be ‘smart’. Prior to this, if you received an Electric Vehicle Home Charging grant to install a home charger you would have had to have one with smart functionality. The new regulations will require greater smart functionality than those that were installed with government help before.
Broadly, smart chargers are preset to only charge your vehicle during off-peak hours between 08:00-11:00 in the morning and 18:00-22:00 in the evening. This is to reduce peak demand on the national electricity grid.
To do this, the smart charger has a data cable that communicates with your energy supplier and via your home network, to an app on your tablet or phone.
You can still override the setting. If you were planning an overnight run to Europe and wanted a full charge at 22:00, you could simply tell the app to charge to 100% through peak time. If you don’t, the system will switch on at or about 22:00 (within 10 minutes as per government requirements to avoid sudden spikes in demand) and charge your vehicle overnight.
If you are on a variable electricity tariff and know that between 01:00 and 04:00 you could get a full charge at just pennies per kWh, you can also programme your smart charger to charge then. This can mean significant savings to you in the long term.
If you rent or live in a block of flats you are eligible for a government grant under the Electric Vehicle Home Charging grant scheme. This was available to homeowners until April 2022 but the scheme has been scrapped. Under the scheme you can get up to £450 off a smart charger (to a maximum of 75% of the cost), fully installed.
Even if you are paying the full £500 or so for a typical charger to be installed, the costs will still be clawed back against purely public charging, as we will discuss later.
What to Consider in Choosing a Home Charger
There are broadly eight things to consider when thinking about a home charger:
- Will the vehicle be parked on-road or on a private driveway?
- Will it be on road or a private car park?
- If on your private property, how far from the fusebox will the charger be?
- How old is the house and do you have a fusebox with a 100A fuse?
- Can you get three-phase A/C?
- Is a solar array possible on your roof?
- What energy supply tariffs are out there?
- Vehicle to Home (V2H) or Vehicle to Grid (V2G)?
Will you be on a driveway or in your own garage?
If you have a driveway, this is simple to arrange. The installer will wire the charger into your fuse box and install it where you need.
Will you be in a car park or park on the road?
There’s no avoiding the fact that you may be among the 17 million UK households that don’t have a driveway or live in flats.
If you live in a block of flats there will be negotiation with the owner or managers of the property, helped with the government incentives we discussed above. In many cases, installation should be possible as it helps future-proof the property for the owners.
For those who live in terraced housing with no driveway, this can be problematic. One or two companies out there have solutions where the cabling can be routed below the pavement. Unless you are disabled and have a legally protected space it can be a bit of a lottery getting your car parked outside your home even if you can get a charger to not present a trip hazard.
In such terraces there is often an unwritten code among residents as to roughly where your car will end up, but the night before a long journey to the other side of the UK, you wouldn’t want to bet on it!
There is no simple answer at the moment in short, but innovations are coming out all the time.
How far will the charger be from the fusebox?
Some people have parking at the bottom of their rear gardens. The cabling and labour in getting the cabling to that point will cost more than a classic semi-detached house where the car pulls up by the side of the house.
Does your house have a 100-amp fuse in the fusebox?
You can check the fusebox to see. When a new meter is being installed – a smart meter for example – the energy company may well upgrade your fusebox as part of the deal. This can cost you nothing.
Some properties have very old electrical systems. This may be the case where you are buying a ‘fixer-upper’ from the estate of an old person who has lived in the house for 40+ years and died there. This may be a major obstacle to installing a charger, but an upgrade to the electrical system may make sense to future-proof it (and ensure the safety of your family anyway).
Can you get 3-phase A/C?
If you are on single phase A/C you can get up to 7.5kW of power into the car. Most cars can handle this and it means you can install the charger for as little as £500. Batteries are getting bigger though and you may want a faster charge. That means three-phase A/C.
For the fastest mains charging (22kW) you must have three phase alternating current (A/C). While most households in the UK are on single-phase A/C they are close enough to the three-phase network to plug in quite cheaply. The easiest way to check whether you are on it is to see if you have three, 100A fuses in the fusebox.
Installing can cost a lot more but if you have a car with a long range battery then it could mean you can get more charge in your energy provider’s off-peak window and save more on a full charge of battery.
Is a solar array possible?
If you have your car at home during the day, then a 4kWp array could put 4kW of charge into your car while it sits at home for £0. With VAT on solar arrays removed and many householders looking to tackle their energy bills, this is one upgrade to your home’s electricity that could hit your bills even further.
Though there are fewer than previously, as of April 2022 there are still EV charging and variable rate energy supply tariffs that go as low as 4.5p/kWh. Completely charging a 50kWh battery would cost you £2.25. If that car did a typical 325Wh per mile, you would get nearly 154 miles per charge, or £0.014 per mile – not even 10% that of a diesel car.
The Octopus Go tariff is notable for actually paying you up to £0.02/kWh at certain times. That means to charge a 50kWh battery you would get £1 off your next electric bill.
Both of these tariffs have their drawbacks. With Octopus much of the day and evening you will pay £0.35/kWh for electricity – 7p above the capped rate – so you need to think about other energy saving measures. With the other, you will pay 11p/kWh for gas and must have a dual-fuel agreement to get that.
Energy companies are businesses and they are in it to make money. All the cheapest deals have drawbacks – you must calculate whether those drawbacks are worth it or to stick to the standard variable rate of 28p/kWh.
V2x means that your EV would be part of your home energy network. It can both be charged and discharge energy either into your home or to the national electricity grid. Vehicle to grid (V2G) and vehicle to home (V2H) are both known as V2x.
Not all EVs have this facility but some do. Instead of installing an expensive home battery you have a bidirectional charger that would let your car power your home at peak hours. One energy provider – Ovo Energy – is piloting V2G just now and would pay you to use energy from your car battery at peak periods, while guaranteeing you the charge you need when you next use the car.
There are issues. If you went fully off-grid or left your car to sell energy every winter’s evening, each charge and discharge would degrade the battery incrementally in the same way as it would if you charged/discharged in a long drive. No studies have been done into the effect of this on car resale values but if someone used software to find out how many cycles the car battery had had, then even if it had low mileage the battery will behave as if it had done the equivalent mileage of a car driven a lot more. It would be like running your ICE car engine as a generator when it’s parked up with all the inherent wear and tear.
That said, a car would justify its value if you hardly used it, leaving it as part of your home energy system while working from home for example. It would effectively be a dual use battery system that can power your home for up to two days in the event of a grid outage as well as a form of transport.
Choices of Charger
In the last section we looked at eight thinking points where it comes to planning a charger installation. In this section we will now look at the decisions as to what charger you will make.
The first thing to remember is, particularly if you are buying an older, used EV, the car might only be able to take up to a certain amount of A/C charge. Check what the limit is – if it can only take up to 7.5kW then it will only make sense to install a single phase system. If newer and it can take up to 22kW, then consider upgrading your home electricity supply accordingly.
Smart chargers cost a little more than a ‘dumb charger’ but are more secure and can save you money as they can be programmed to only charge the vehicle in off-peak times. Many EV tariffs are only accessible if you charge at off-peak so the added cost of the charger will be immediately offset by the savings. Here’s some simple maths:
– A 50kW charge at 28p/kWh would be £14
– The same battery charged at £0.045 would cost £2.25.
That’s almost as big a jump as from diesel to EVs!
These cost significantly more than straight smart chargers but, forgetting the unknown maths of battery degradation and depreciation, can save you money by using off-peak energy at peak times.
Costs – Home Charger Installation
For a 7.5kW smart charger, expect to pay £400-£500 fully installed at a typical home. At the top end, with something like a 22kW three-phase V2x system, expect to pay more than £1,500. Expect to pay:
• £750 for a 3.6kW home charger with no grant, fully installed
• £900 for a 7kW home charger with no grant, fully installed
• £1,500 for a three-phase, 22kW home charger with no grant, fully installed
Variables that can affect a home charger installation include:
– Distance from the fusebox
– Whether it is on-road or off-road charging
– Age of home and state of electrics
– Whether you want three-phase
– Type of charger you choose
– Whether you are eligible for a home charger grant
With these in mind, you should be able to keep your charger installation costs to a minimum. As you will see in the next section, it is a lot more convenient and easier than using a public EV charging point!
List of Home Charger Manufacturers
This is a list of leading UK home chargepoint providers. As discussed above, the companies will use local installers to install your EV for you.