Prices vary according to the theoretical maximum charging speed of the charging station plug (kW). In the case of the Volvo public charging service Large tariff, higher potential maximum charging speed of the charging station means lower prices. When searching for a charging station, you can filter by plug power level (kW) to know in advance which prices will apply.
To take an example, you may see the below information for the Large tariff on the tariff page (note that the given prices are only for the sake of the example):
DC charging
Up to 99 kW
0,63 GBP / kWh
after 90 minutes, up to 99 kW
+ 0,20 GBP / min
from 100 kW
0,5 GBP / kWh
after 90 minutes, from 100 kW
+ 0,20 GBP / min
For example, if you charge at a High Speed charging station with a maximum charging speed of 300 kW, but your vehicle battery is only able to charge at a maximum of 85 kW, the tariff applied will still be the "From 100 kW" tariff, because only the theoretical maximum charging speed of the charging station plug is taken into account, which in this case is 300 kW. This means that you would be charged 0,5 GBP / kWh.
These prices are always displayed before charging on the map, within the app or on the Volvo public charging service website.