Single-Phase vs Three-Phase EV Charging: What UK Homeowners Need to Know
The Quick Answer
Most UK homeowners should stick with single-phase (7kW) charging. It charges a Tesla overnight in 8–10 hours, costs £800–1,200 to install, and is more than fast enough for daily driving. Three-phase (22kW) charging is faster but requires an expensive electrical upgrade that rarely makes financial sense for home use.
What's the Difference?
Single-Phase (Most UK Homes)
- Max charging speed: 7.4kW
- What it means: Your home receives electricity through one wire (one phase) from the grid
- Charging time: Tesla Model 3/Y charges from 20–80% in roughly 5–6 hours
- Full charge: 8–10 hours for a Model 3/Y, 12–14 hours for a Model S/X
- Availability: ~95% of UK homes have single-phase power
Three-Phase (Rare in UK Homes)
- Max charging speed: 22kW
- What it means: Your home receives electricity through three wires (three phases) from the grid
- Charging time: Tesla Model 3/Y charges from 20–80% in roughly 2–3 hours
- Full charge: 3–4 hours for a Model 3/Y, 5–6 hours for a Model S/X
- Availability: ~5% of UK homes, mostly larger or newer properties
Speed Comparison
| Scenario | Single-Phase (7kW) | Three-Phase (22kW) |
|---|---|---|
| Daily top-up (30 miles) | ~1 hour | ~20 minutes |
| 20–80% charge (Model 3) | ~5 hours | ~1.5 hours |
| Full charge (Model 3, 60kWh) | ~8.5 hours | ~2.7 hours |
| Full charge (Model S, 100kWh) | ~14 hours | ~4.5 hours |
The speed difference looks dramatic on paper, but consider this: if you plug in overnight, both give you a full battery by morning. The three-phase advantage only matters if you need to charge during the day with limited time.
Do You Have Three-Phase Power?
Most people don't know what they have. Here's how to check:
Check Your Consumer Unit (Fuse Box)
- Single-phase: One main switch (or one row of circuit breakers)
- Three-phase: Three main switches, or a three-pole main switch, often with coloured labels (red, yellow, blue or brown, black, grey)
Check Your Meter
- Single-phase: One set of readings
- Three-phase: Three sets of readings or a digital display showing L1, L2, L3
Check Your Main Fuse
- Single-phase: Typically rated at 60A or 80A (single)
- Three-phase: Three separate fuses, typically 60A or 100A each
Still Not Sure?
Ask your electrician when they visit for a charger installation quote — they'll tell you immediately.
Cost of Upgrading to Three-Phase
If you don't already have three-phase power, upgrading is a significant project:
| Item | Cost |
|---|---|
| DNO application and supply upgrade | £1,500–3,500 |
| Electrical installation work | £1,000–2,000 |
| New consumer unit (fuse box) | £500–800 |
| Groundwork (digging trenches) | £500–2,000 |
| Total estimate | £3,500–8,000+ |
On top of that, you'd still need a three-phase charger (~£475–595 for a Tesla Wall Connector or Wallbox Pulsar Plus in three-phase mode) and installation (£400–600).
Total cost for three-phase EV charging from scratch: £4,500–9,000+
Compare that to a standard single-phase charger installation: £800–1,200 total.
Does Your Tesla Even Support 22kW?
This is the crucial detail that many people miss. Not all EVs can accept 22kW AC charging, even if your home supply supports it:
| Tesla Model | Max AC Charging Speed | Benefits from Three-Phase? |
|---|---|---|
| Model 3 (Standard Range) | 7.4kW (single-phase only) | No |
| Model 3 (Long Range/Performance) | 11kW | Partially (11kW, not 22kW) |
| Model Y (all variants) | 11kW | Partially (11kW, not 22kW) |
| Model S | 16.5kW | Mostly (16.5kW, not full 22kW) |
| Model X | 16.5kW | Mostly (16.5kW, not full 22kW) |
Key takeaway: The Model 3 Standard Range can only charge at 7.4kW regardless of your power supply. The Long Range and Model Y top out at 11kW. Only the Model S and X get close to utilising a 22kW supply, and even they don't use the full 22kW.
When Three-Phase Makes Sense
It's worth it if:
- You already have three-phase power — no upgrade cost, just buy a three-phase charger
- You have a Model S or X and need to charge quickly during the day
- You have multiple EVs and want to charge them simultaneously at higher speeds
- You're building a new home and can include three-phase in the initial electrical design (cheaper than retrofitting)
It's NOT worth it if:
- You'd need to upgrade your supply — the £3,500–8,000+ upgrade cost would take years to justify through faster charging
- You have a Model 3 Standard Range — it can't charge faster than 7.4kW on AC regardless
- You charge overnight — 7kW gives you a full battery by morning anyway
- You mainly need a quick top-up — for fast daytime charging, a 15-minute Supercharger stop is cheaper and faster than a three-phase home upgrade
Which Chargers Support Three-Phase?
Of the chargers we review, two support three-phase:
| Charger | Single-Phase | Three-Phase | Price |
|---|---|---|---|
| Tesla Wall Connector | 7.4kW | 22kW | £475 |
| Wallbox Pulsar Plus | 7.4kW | 22kW | £595 |
| Ohme Home Pro | 7.4kW | No | £535 |
| Pod Point Solo 3S | 7.4kW | No | £999 (installed) |
| Easee One | 7.4kW | No | £405 |
If you do have three-phase power, the Tesla Wall Connector offers the best value — at £475, it's the cheapest three-phase capable charger and integrates seamlessly with your Tesla.
Our Recommendation
For 95% of UK Tesla owners, a 7kW single-phase charger is the right choice. It provides a full overnight charge, costs a fraction of a three-phase setup, and the charging speed is more than adequate for daily driving.
The maths is simple: spending £4,000–8,000 on a three-phase upgrade to save 5–6 hours of charging time (while you're asleep anyway) doesn't make financial sense. That money is better spent on solar panels, a smart tariff, or simply saved.
If you already have three-phase power, then by all means take advantage of it — the Tesla Wall Connector supports up to 22kW and costs just £475. But don't upgrade your electrical supply just for faster home charging.
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