On Sat, 14 Jul 2018 13:31:15 +0100
Recliner wrote:
On Fri, 13 Jul 2018 19:22:45 +0100, Graeme Wall
wrote:

On 13/07/2018 19:12, Jarle Hammen Knudsen wrote:
On Fri, 13 Jul 2018 16:41:57 +0100, Roland Perry
wrote:

In message , at 16:21:33 on Fri, 13
Jul 2018, John Williamson remarked:
On 13/07/2018 16:09, Roland Perry wrote:

What's important for the EV-charging scenario is that is if several
dozen houses are supplied by an 200A street main at 230v from the
local substation, how can more than a handful charge an EV overnight
at 50 amps?

The grid will eventually have to be upgraded, though for domestic use,
an off peak slow charge at 3 kilowatts is usually enough for a day's
use.

The problem with off-peak is that everyone is expecting to use it, so it
becomes just as much in demand as "peak".

3 kilowatts is double the normal average power consumption of houses.

The street main is usually 200A per phase, though.

Which if we believe grid figures that an average household is perhaps
1.5kW means it can feed (200/(1500/230))x3 = 90 houses.

Still wondering where even the level 2 Tesla chargers (80 amps at 230v)
will get their supply from.

The future is hydrogen.


As it has been for 50 years…

50 years ago, you couldn't drive a hydrogen-powered car from John
O'Groats to Land's End, as Autocar did last month:
https://www.autocar.co.uk/car-news/n...s-land%E2%80%9
9s-end-hydrogen-fuel-cell-car

The physics hasn't changed in 50 years. I read somewhere (can't find it) that
using hydrogen for energy is so inefficient with our current grid of mixed
fossil fuel power stations that you'd create a lot less total CO2 just using a
diesel vehicle though far better to use the electricity you waste on creating
H2 just to convert it back to electricity again to charge a battery vehicle.

Also hydrogen is hard to transport and store in large amounts and requires a
lot of electricity to compress it over and above that required to create it
from water or (even worse) steamed out of natural gas in the first place.