7.4 kW at home
Most UK houses have a single-phase supply. On that supply, 7.4 kW is the usual maximum for a home charger. Many cars then add roughly 25 to 35 miles of range in an hour. Yours may do less in winter or if the battery is nearly full. Left overnight, a normal commute is rarely the problem.
22 kW
22 kW needs three-phase power, a heavier supply used in some larger homes and many commercial buildings. If the house is single phase, a 22 kW unit will not charge at 22 kW. The survey looks at the supply before that model is offered. Guessing from the street is not enough.
Public rapids
Motorway chargers are much faster, and much more expensive per unit of electricity. They are for journeys, not for every night. The savings calculator lets you put a share of charging on public prices so that mix is visible.
None of these speeds is installed, or promised, from a web page. Get an indicative quote or read what the survey checks.