22kW Three-Phase EV Charging

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22kW Three-Phase EV Charging

Electric vehicles (EVs) have taken the automotive industry by storm. There are more EVs on the road today than there were a few decades ago, and this trend will keep on increasing.

Due to the imminent shift from ICE vehicles to electric vehicles, the latter are now sold at more affordable prices, making them more accessible to the general public.

As the number of EVs increases, so does the demand for more charging points and stations. To meet future EV charging needs, the UK needs approximately 29,000 EV chargers across the country. This includes home EV chargers, commercial EV charging points, and public EV charging stations.

EV chargers come at different speeds – slow, fast, and rapid – and can either be single-phase or three-phase, and you need to choose the right one according to your needs in order to enjoy their full benefits.

Since most EV owners do not understand the differences between them and how and when they should be using 22kW three-phase EV charging, here is a guide explaining the costs and whether it is worth it:


You can charge your EV at a range of different speeds depending on a couple of factors such as the power source, the output of the charger, and the charging capacity of your electric car.

The most common home EV charging speeds include:

  • 3kW – very slow (Three-pin plug)
  • 6kW – slow (Home EV charge point)
  • 4kW – fast (Home EV charge point)
  • Up to 22kW – very fast (Home EV charge point)

A 2.3kW three-pin plug is the slowest out of the lot and is generally recommended only as a backup option. The 7.4kW charger is one of the most common options for home EV charge points and is recommended by most EV charger installers.

The 22kW three-phase charger is the fastest EV charger you can install in your home, but for it to be three-phased, a few criteria need to be fulfilled in order to use it.

The charge point will have to be “three-phase compatible” and use something known as a three-phase electricity supply. In addition to that, the EV itself needs to be compatible with the 22kW charging output.

So, what does three-phase charging mean?

Alternating current (AC) power supply can be classified into single-phase and three-phase. Both allow EV owners to charge their cars through single and three-phase power outlets, respectively.

The difference between them is that in the former, the power flows through a single conductor, whereas in the latter, it flows through three conductors. As compared to single-phase charging, three-phase charging has a higher power transfer capacity of 22kW.

22kW EV charging refers to the rate at which the electricity transfers from the EV charger into the EV. It is thrice as fast as 7kW charging and can only be supported by properties that have a three-phase incoming power supply.

Since a vast majority of residential properties in the UK do not have a three-phase power supply, it means that 22kW EV charging is a rarity in homes.


Whether or not you can have 22kW three-phase charging depends on two things:

  • Your property’s electricity supply,
  • How much power your EV can receive.

Since most homes in the UK have a single-phase power supply that provides up to 7kW to charge up an EV, most EVs charged at home are done at 7kW. This gives roughly around 30 miles per hour.

To charge your EV at a higher rate, such as 22kW, you will need a three-phase electricity supply on your property.

However, as mentioned earlier, since a huge chunk of the residential sector operates on a single-phase supply, most homes are unable to support fast charging of around 22kW.

On top of all this, you have to make sure that your electric car can take advantage of 22kW three-phase charging at home since, in the end, it is the electric car that decides the charging speed it will accept.

Installing a faster home EV charger doesn’t necessarily mean that your EV will also charge faster. This is because both systems have to be compatible with each other in order to work.

For instance, imagine a single-lane tunnel. No matter how many cars you try and squeeze through it, since it has only one lane, it can accommodate only a certain number of cars at a given time.

Similarly, if your EV isn’t made to accommodate 22kW three-phase charging, it wouldn’t do you any good if you install a 22kW charger since your car won’t charge at the expected rate.

Therefore, to fully benefit from 22kW three-phase EV charging, you will need:


One way to find out if you have a three-phase power supply in your home is to contact your electricity provider and ask them.

Since most homes in the UK do not have a three-phase power supply, chances are that you don’t either. However, you can always check to be sure.

If you do not, you can upgrade to one from a single-phase so that the incoming power to your home is tripled.

This means that you can use a 22kW three-phase charger and charge three times as fast as a single-phase 7kW charger. In addition to that, it is also ideal for future-proofing your property.

You may contact your District Network Operator (DNO) to gauge the suitability of the system and provide you with a quote for the upgrade.

The prices may vary considerably, with the process often being very expensive, ranging from £3,000 to £15,000.

For this reason, most EV drivers in the UK will install a 7kW charger in their homes since that is the fastest charger you can get on a single-phase supply.


While it may seem like the best option to go for 22kW charging, it is important to take into consideration that the majority of EVs in the market at the moment are not compatible with 22kW charging.

There is something called an onboard charger (OBC) inside an EV that determines the maximum rate of power the car can accept. Currently, this varies between 3.6kW, 7kW, and in some cases, 11kW.

So, for instance, if you have a 22kW three-phase charger, but an EV that can accept only 3.6kW, the maximum rate of power the car will be able to accept will be only 3.6kW.


The average time it takes to charge an EV depends on 4 factors:

  • The incoming power supply on your property
  • The charging capability of the EV
  • The on-board charger of the EV
  • The battery size of the EV

In the UK, there are 3 main types of EV chargers that are differentiated according to how fast they charge an EV. They are referred to as ‘slow’, ‘fast’, and ‘rapid/ultra-rapid’ chargers.

Their speeds are obvious by their names, with slow chargers taking the longest and rapid chargers charging a full battery in hardly a few minutes.

  • Slow chargers charge up to 3.6kW and can take between 6 to 12 hours for a full charge. They are most commonly used in homes for overnight charging.
  • Fast chargers charge around 7kW to 22kW and can take between 3 to 5 hours for a full charge. For now, they are the most common type of charging point.
  • Rapid and ultra-rapid DC chargers can handle charging outputs of around 50kW to 350kW, allowing you to charge your batteries to 80% in hardly 20 minutes. They are mostly found in shopping centres, car parks, and service stations.

When talking about fast chargers, a 22kW three-phase charger can charge three times faster than a single-phase 7kW charger.

Also, the capacity and health of the battery and the power of the charger play a crucial role here. The bigger the size of the battery and the slower the charging output, the longer it will take to charge it from empty to full.

To get a better idea of the relation, here are the battery capacities, charging powers, and times for some of the most common battery sizes:

  • An electric car with a 32kW battery will take around 9 hours to charge with a 3kW charging point, and around 4 hours with a 7kW charging point.
  • An electric car with a 40kW battery will take around 11 hours to charge with a 3kW charging point, and around 4.5 hours with a 7kW charging point.
  • An electric car with a 60kW battery will take around 17 hours to charge with a 3kW charging point, and around 7 hours with a 7kW charging point.
  • An electric car with a 100kW battery will take around 27 hours to charge with a 3kW charging point, around 11.5 hours with a 7kW charging point, and around 4.5 hours with a 22kW charging point.


When compared to a 7kW standard EV charger installation, the cost of fitting a 22kW charger is usually higher since it involves more material and labour.

While the accurate costs depend on the amount of electrical work involved since you will need thrice as much material and cabling that is thrice as big, it would naturally take longer to connect and test everything.

The additional amount depends on the specific job but you can expect to pay an additional £700 to £900 on top of the installation.

Under the Government’s Electric Vehicle Homecharge Scheme (EVHS), you can receive a grant of up to 75% of the EV charger’s cost, with a cap set at £350 per installation.

To benefit from the grant, you must:

  • Own an OZEV-approved vehicle,
  • Have off-street parking suitable for EV charger installation,
  • Have the installation carried out by an OZEV authorised installer, and
  • Have charge points that use smart technology.


Since most properties in the UK do not have a three-phase power supply, plus it can be expensive to have the existing systems upgraded, it may not be worth it to install a 22kW three-phase charger on your residential property.

It may not be such a great idea, more so because most EVs won’t be able to take full advantage of a 22kW charger in their home anyway.

Since most EV charging in homes takes place overnight, even if you have a three-phase power supply and a compatible electric car that could charge between 11kW to 22kW, it wouldn’t make a difference since it wouldn’t matter how fast or slow the charging took place.

To make it clearer, imagine charging your smartphone with a fast charger overnight while you’re asleep. While it is true that, as compared to a regular charger, it will charge in one hour instead of two.

However, in both scenarios (slow and fast charger), your phone will be fully charged when you wake up in the morning and you won’t have noticed any time-saving.

For EV drivers who usually charge their EVs at home overnight, it wouldn’t be very wise to invest in a 22kW three-phase charger. For them, a 7kW charger would be more than enough.


If you have a three-phase power supply at home, then you may consider a 22kW charger as an option. However, you need to keep in mind that it will cost you more, both in terms of the unit price and the installation.

22kW three-phase charging may also be useful if you have multiple electric cars. For instance, if you have a few EVs at home, having a faster charger option may offer you more convenience. A 22kW in this scenario would allow you to charge your cars faster, making it easier to share a single charger.

A three-phase power supply is more commonly found in commercial settings such as offices, shops, factories, restaurants, and shopping centres; therefore, 22kW charging is more often seen in workplace office chargers and public car parks.

Oftentimes when you see a residential property using a three-phase option, it is because it was converted into a house from a workplace. For instance, a home that was originally an office, a pub, or an old factory.

Having said that, it is now becoming more common for new domestic builds, such as houses with 6 or more bedrooms, to have a three-phase power supply from the get-go, in which case, it could be a good option to consider getting 22kW fast charging.

In the end, it all depends on what you need and which type of charger works best for you. You need to keep in mind the number of electric cars you have and how often you need to charge them.


At Calder Electrical, we install EV chargers in line with the current regulations and can offer a government incentive to reduce the installation costs for both domestic and commercial properties.

There are various chargers currently in the market and it can be a little confusing to choose the best one for your needs.

We will take out the hassle and provide you with the most suitable and affordable option, ranging from the standard systems to the smart ones that are becoming increasingly popular.

We are authorised and registered OZEV installers and our charge points come with a 3-year warranty. We offer all kinds of different options to choose from, such as wall-mounted to freestanding pedestal units with different types of chargers and charging speeds.

Contact us here or call us on 0800 612 3001 for our expert opinion and professional services!

Photo by Waldemar Brandt on Unsplash