The 22kW Question: Why Most UK Driveways Are Fine With 7kW

There's a particular kind of upsell in the home charging market that goes roughly like this: you're spending anyway, so why not go for the 22kW model? It sounds sensible. It is, for a small minority of drivers. For everyone else it's an expensive answer to a question they don't have, and it often drags a lot of paperwork along with it.

Let's be clear about the framing: this isn't an argument against fast home charging. It's an argument for spending the money where it actually changes your day — load management, a sensible tariff, a decent cable run — rather than on raw kilowatts you'll never use.

What 22kW actually requires

A standard UK home has a single-phase supply, typically with an 80A or 100A cut-out. At 230V that puts a practical ceiling of around 7.4kW on a single-phase charge point, and that's before you account for the oven, the shower and everything else competing for the same headroom. To hit 22kW you need three-phase power — 400V at 32A per phase — which most UK houses simply don't have.

Getting it means asking your distribution network operator for a supply upgrade. Depending on where you live and what's in the street, that can mean anything from a fairly routine job to new cabling, a new meter position and a genuine five-figure quote. Add the electrician's side — three-phase distribution, a longer or heavier cable run, isolators, protection — and the numbers climb fast. There is no grant scheme that makes that arithmetic comfortable.

The mileage maths is unforgiving

A typical UK car covers somewhere around 7,000 to 8,000 miles a year. At a realistic 3.5 miles per kWh in mixed driving, that's roughly 20 to 25kWh a week. Even a heavy 12,000-mile year works out at around 65kWh a week — call it ten hours on a 7kW charger, spread across seven nights.

Most people plug in two or three times a week and let the car sit. A five-hour off-peak window on a 7kW unit delivers about 35kWh, which is more than the average daily commute by a comfortable margin. The bottleneck for most households isn't the charger. It's how long the car is parked, and it's parked for eleven hours a night.

Check what your car can actually accept

Here's the bit that gets skipped: many EVs cap AC charging at 7kW, and a good number cap at 11kW even when three-phase is available. A 22kW charge point will happily hand over 7kW to a car that only asked for 7kW. You'd be paying for supply capacity your vehicle can't use.

If you're shopping, look up the on-board charger rating for your specific model and trim before you look at charge points. If long journeys are the concern, the answer isn't a faster home charger — it's DC rapid charging en route, which is a completely different piece of infrastructure and not something you install on a driveway.

The cases where 22kW genuinely earns its keep

There are real ones, and they're worth naming honestly.

You already have three-phase. Farms, workshops, small business premises, some newer build properties and conversions with commercial heritage. If the supply is there, the incremental cost of a three-phase unit is modest and the headroom is free.

You're running a small fleet or a working vehicle. Taxis, private hire, courier work, care agencies, anything doing 200-plus miles a day with a short turnaround. When the car needs to be back out in three hours, 22kW is the difference between viable and not.

Multiple EVs, one charge point. Two cars sharing a single unit with tight overnight windows can justify more power — though load management and a bit of scheduling often solves the same problem for less.

Shared or communal driveways. Where charging has to be fair and fast because someone else is waiting, capacity has a social value as well as a technical one.

If none of those describe you, the case is thin.

What actually improves daily charging

Dynamic load management is the upgrade worth having. A current clamp on your incoming supply lets the charger throttle back when the house is busy — kettle, shower, oven — and ramp up again when it isn't. That's what lets a household with an 80A fuse run a 7kW charger confidently without asking the DNO for anything. It's the difference between a charge point that trips the main switch on a cold Sunday and one that quietly gets on with it.

Beyond that: pick a unit that plays nicely with time-of-use tariffs, so the cheap overnight window is used automatically. Add proper cable management so the run is tidy and the plug isn't lying in a puddle. If you already have three-phase and solar, an 11kW unit with solar diversion is a far more useful spend than 22kW. And get the cable sizing right for the length of run — voltage drop on a long driveway run is a real constraint, not a theoretical one.

The honest verdict

For the overwhelming majority of UK households, a smart 7kW charge point with load management, installed properly, is the correct answer. It charges overnight, it's cheap, it works with off-peak tariffs, and it doesn't require a conversation with your network operator.

Spend the difference on a better installation, a tariff that pays you back, and maybe a bit of solar or battery down the line. Buy the 22kW unit when you can point to three-phase on the wall and a mileage sheet that demands it — and not a moment before.