"Roland Perry" wrote in message
...
In message , at 17:34:59 on Mon, 25 May
2009, David A Stocks remarked:
And in London the problem is distributing the electricity from the grid
to the end users. Even if there was a plentiful source of electricity,
you'd have to do quite a lot of work to get it where it's needed.

Just dig up the relevant bit of road/pavement and tap into the existing
domestic supply cables that are under every street. This must have been
the approach for the existing charging points, and it's hardly rocket
science.

You'll soon overload it if it's more than a few charging points per
street.
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. 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.

Nor does this approach solve getting the extra power from the outside
world to the substations.
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.

D A Stocks