Commercial AC charging · UK 2026
A 22kW charger has roughly three times the nameplate power of a 7kW unit — but it can also place three times the electrical demand on the site, and many EVs will not draw the full 22kW on AC. Choose around dwell time, vehicle capability and site capacity.
Technical data checked: 31 August 2026
The core difference
The commercial decision is a trade-off between energy delivered during the parking window and the infrastructure needed to make that power available across multiple bays.
*Theoretical energy based on rated power × time. Real charging is affected by vehicle limits, battery state, charging losses and power management.
Parking time
A commercial charger exists to replace the energy the vehicle needs before departure. Once that requirement can be met inside the dwell window, extra charging speed may add little operational value.
The vehicle can be the bottleneck
AC charging passes through the vehicle's onboard charger, which converts AC electricity to DC for the battery. The vehicle's onboard charger therefore sets an upper limit on the AC rate it can accept.
If a vehicle can accept only 11kW AC, connecting it to a 22kW chargepoint does not double that capability — the vehicle will still charge at up to about 11kW.
Site capacity
One 22kW charger may be manageable. Twenty can represent 440kW of nameplate demand. That is why commercial charger design is about the whole estate, not the label on one wallbox.
Smart load management can reduce coincident demand by sharing available site power between vehicles, but it does not create extra grid capacity. Charger power should still be aligned with the energy that vehicles genuinely need.
Same site, different charger power
The comparison below uses the same eight-socket workplace assumptions in our V2 cost engine: medium cable routes, light civils, RFID, load management and electrical capacity not yet confirmed.
Lower base hardware and a smaller electrical planning allowance.
Higher charger cost plus a larger allowance for three-phase electrical capacity risk.
A site with abundant three-phase capacity may narrow the difference considerably. A constrained site may make 22kW much more expensive if distribution or connection work is required.
Which should you choose?
Cars parked for most of the day can often recover daily mileage at 7kW, allowing more sockets to share the site's available capacity.
Workplace charging guideAn overnight stay can provide 8–12 hours of charging time. More bookable sockets may add more guest value than fewer 22kW units.
Hotel charging guideRestaurants, leisure sites and visitor parking with shorter dwell periods can benefit where vehicles and three-phase supply support higher AC rates.
Check the target vehicle mix first.Long overnight van dwell may suit AC; shorter turnaround or larger energy requirements may justify DC rather than simply moving from 7kW to 22kW.
Fleet / depot guideWorkplace Charging Scheme
The current scheme can cover up to 75% of eligible purchase and installation costs including VAT, capped at £500 per eligible socket and 40 sockets across all sites.
So an eligible 22kW socket does not receive a larger per-socket grant simply because it has more power. Where 22kW increases hardware or electrical cost, the business may fund more of that difference itself.
Current scheme closes31 March 2027
Before specifying 22kW
If these questions cannot be answered, specifying 22kW everywhere is premature.
Dwell time — is 7kW actually too slow for the vehicles' departure deadline?
Vehicle capability — how much AC power do the expected EVs accept?
Three-phase supply — does the site have enough usable capacity for the intended number of 22kW sockets?
Scale — would more 7kW sockets serve more drivers than fewer high-power sockets?
Load management — can diversified charging reduce the required coincident demand?
Future fleet — will likely future vehicles or use cases benefit more from higher AC power?
7kW vs 22kW FAQ
Its rated power is roughly three times higher, but actual charging only reaches that level if the vehicle's onboard AC charger can accept 22kW and the installation can supply it. An 11kW-capable vehicle connected to a 22kW chargepoint will still be vehicle-limited to around 11kW.
For normal UK commercial AC charging, 22kW uses a 400V three-phase supply at around 32A per phase. A typical 7kW outlet uses 230V single-phase at around 32A.
Often. A theoretical 7kW socket can deliver 56kWh during an eight-hour parking window. If that comfortably replaces the daily energy a vehicle needs, higher charging power may not create additional operational value.
The vehicle's onboard AC charger sets its maximum AC charging rate. For example, Tesla currently states an 11kW maximum on 400V three-phase for Model S, Model 3, Model X and Model Y, so a 22kW AC point cannot make those cars accept 22kW.
Not automatically. Overnight guests have long dwell periods, making 7kW highly practical. 22kW is more valuable where stays are shorter and the site has suitable three-phase capacity.
No higher per-socket grant cap applies just because a charger is 22kW. The current WCS is capped at £500 per eligible socket and 40 sockets, subject also to the 75% eligible-cost limit.
Sources & methodology
Power and supply references use current UK government commercial chargepoint specifications and Energy Saving Trust fleet guidance. Vehicle examples come from current manufacturer charging information. Cost comparisons use the same V2 model as our commercial EV charging calculator.
Planning information, not electrical design: CommercialEVCharger.co.uk is independent. Exact charger rating, phase loading, diversity and connection design must be confirmed by a competent installer using site and vehicle data.
Compare the economics
Change only the charger power in our calculator to see how hardware, electrical allowances and total project range move.