On Thursday, 18 April 2019 10:01:46 UTC+1, NY wrote:
"The Natural Philosopher" wrote in message
...

Since electric motors should be much more efficient than internal
combustion engines the above figures are pessimistic but even if the
power requirement was only 30% of the above they'd still be problematic.

If we can actually produce an acceptable battery car in due course for
more than intra urban short hops, then all the infrastructure is buildable
over the same sort of period that a petrol and diesel based
infrastructure was rolled out in the last century.

Yes. What worries me is that we may find that we have to alter our habits,
scheduling in longer breaks whenever the car is getting low on power,
whereas we are used to filling up in a few minutes whenever we need to
(without having to plan ahead).

It's fine for people who have a commute with recharging points at both ends,
but I bet there will be lots of times when you get to work and find that
there are no free charging points in the car park so you waste a lot of work
time going round the neighbouring area to find somewhere that you can hook
up so you'll be able to get home again in the evening.

Hopefully the number of charging points will keep pace with the number of
cars (ideally one for every parking space in a car park). I've heard that in
some places, people with petrol/diesel cars are parking in charging spaces -
deliberately rather than just because it's the only free space, as if in
some sort of protest.

Fast recharging sounds great until you do the sums and realise just how much
energy you need to get into a car battery to match the "recharge rate" of
filling up with a tank of petrol/diesel, and how much of that energy, even
at very high efficiency, will go as heat, with the problem of how to dispose
of that heat safely to avoid things melting.

There might be one way to get lots of charge points out there. Permit house & business owners to resell grid electricity at sufficient profit to make it worth fitting a charging point outside.


If we can crack the power problem, electric cars sound great: to have a car
that can accelerate smoothly from 0 to 60 without any mechanical change of
gear, and where the driver directly controls the rate of the car's
acceleration, without having to make allowances for acceleration in a higher
gear being less, and without having to overcome the problem of smoothly
changing down after approaching a junction and wanting to accelerate away
again.

Cars have been able to do that for decades using variable gearing. Except the decreasing acceleration at speed which happens with all engine types: petrol, diesel, electric & steam.


NT