mapj1:

The hiccup is one of rate of transfer of energy - the speed to refuel a petrol car means the service station borders on the burn rate equivalent to a modest power station . . .

 

Now an electric car needs less KVA, being more efficient, perhaps more like 30kVA

 

At the motorway services, perhaps 5-10 cars may be filling at once when busy

(Think how that will affect off-peak demand and "cheap rate" tariffs - we could start a whole new topic on this.)

I think we could also start a whole topic on the updates needed to the way we run the LV (230/400) network. At the moment the substations are all sized on about 2kVA per house, because that is the average demand over time, smoothed over a large number of houses, so a 400A substation fuse feeds 25-35 houses, each of whom imagine they have a 100A supply, and perhaps  half a dozen street lights. Adding charge points for the first 1% who would like one is easy, as the extra load is negligible.  When that becomes something like 10% all charging at once, the substation is overloaded.

And there is a problem for all those cars parked nose to tail on both sides of terraced streets - I'm not sure we want extension leads out of every bedroom window, but at the cheap end of town it is what we will get if we do not make a formal provision.

The average UK car does around 10k miles a year    That is  30 miles a day, again smoothed over many.  That 30kVA mentioned above, gets perhaps you perhaps100 miles so recharge every 3 to 4 days, or more likely, a shorter charge taken more often, but a similar total.


It will sort of work, but no without a lot of careful load management, and maybe adding thermostatic fans on the substations. one of many ideas being trialled as we type..