David A Stocks wrote:

A trickle-charge point is equivalent to a 13A socket inside a house. The
distribution system would barely notice that, even if everyone started
charging a car at the same time - we're talking about a system which copes
with events like a third of the nation's households putting a kettle on the
boil at the start of a TV commercial break.

Yes, but a third of the nation's households will still put the kettle on
during a commercial break... while their car is plugged in outside. Peak
loads add. (Give or take the fact that everyone's watching different
channels these days)

Fast charge points would
probably require rationing, probably by making them expensive to use. The
peaks in electricity demand tend to occur during the late afternoon when
cars are more likely to be out on the road than sat on charging points.

With a suitably non-trickle feed, the charging would be controlled so that
it takes place during the troughs in demand. You'd have to say something
like 'charge me by 7.30am' and the charger would know that if it hadn't got
enough cheap (aka trough) power by 4am it would have to charge on
'expensive' power. But you still need the grid and generating plant to
supply that. The system is a very complex series of many feedback loops, so
controlling it is quite tricky.

We're talking about a gradual take-up over the next 20 years or so, and it
should all be very predictable. I suspect the major challenge is
generating the electricity, not the distribution.

I saw a figure somewhere that a new HV national grid connection can take up
to 7 years. So you need a lot of planning.

Theo

David A Stocks wrote:

events like a third of the nation's
households putting a kettle on the boil at the start of a TV
commercial break.

I've just thought of a solution to that problem - kettles should have a
standby mode in which they consume as much power as when they are boiling
water.