EV Charging in the UK

On Sat, 15 Jun 2019 20:50:29 -0700 (PDT), Rick C
<gnuarm.deletethisbit@gmail.com> wrote:


>I have to acknowledge that if this 2 kW number is correct and a large fraction of homes in the UK receive such meager distribution, home EV charging of any significant fraction of the cars would be impossible.

While in some countries it is a necessity for a family to own one or
more cars, this is not the situation in large parts of Europe. This
reduces the number of EVs that needs charging in an area.

>Otherwise adding a simple 13 amp outlet accessible to the EV would suffice for charging up to 150 miles per night or more.

What is the EV consumption ? If one believe the EV manufacturers
claims, you should be able to drive 5-6 km with 1 kWh. At 6 km/kWh
then 240 km translates to 40 kWh. A 3 kW (13 A 240 V) socket could
barely supply that in 14 hours each evening and night.

However that daily 240 km sounds quite a lot, i.e. commuting 120 km in
one direction. No way, that is not a realistic average commuting
distance in UK. That would be spending more than 3 hours in the car
each day.

 

[Jan Panteltje]

On a sunny day (Sun, 16 Jun 2019 09:45:09 -0000 (UTC)) it happened Cursitor
Doom <curd@notformail.com> wrote in <qe5335$7ms$6@dont-email.me>:

On Sun, 16 Jun 2019 05:33:10 +0000, Jan Panteltje wrote:

Kid's brains were polluted by climate games played by that what's his
name (cannot remember the polar bears idiot) politicians for profit.
It is a political game for profit.
Mass manipulation.

Exactly.

Making all transport electric is wrong, you need to diversify.
One hacker, one solar storm , one high altitude nuke, is all it takes to
kill most of civilization if all is electric,
It will happen, (looks up date, oops)...
Al Gore, that is where the crap started.

Aren't we all supposed to be dead by now, according to Gore's apocalyptic
hockey stick? ;-)

Not only that, according the the Club Of Rome wisecracks,
there would be no more oil and the sidewalks would be full of people.
I think they did the simulations in BASIC on the first IBM PC
https://en.wikipedia.org/wiki/Club_of_Rome

Like Gore, they were / are? no scientists, but politicians ..
with an agenda.

Keeping the people like a puppet on a string and creating fear to rule them.

And they still play the same game today:
https://www.nature.com/articles/d41586-018-07117-2

It is a higher probablility that the next war (Iran?) that US is trying to provoke
will unite all countries of the world (Russia, China, Europe, India, Pakistan, others)
in a direct nuclear attack on N America.
They will be happy with a boat crossing the Atlantic or Pacific looking
for an not-polluted island or place.
Those that cross in their bathtub should not pull the plug,

I ain't kidding you not
some fugitive migrant guy tried to cross the north sea in a home made raft.
Some fishing boat spotted him of the coast,
and the coastgard picked him up an handed him to the police:
https://www.youtube.com/watch?v=0vfdkRQTeSM (in Ducth)

What a boat ;-(

What people will do in desperation.

 

[Martin Brown]

On 16/06/2019 10:34, Rick C wrote:

On Sunday, June 16, 2019 at 4:58:17 AM UTC-4, Martin Brown wrote:
On 16/06/2019 08:15, Tom Gardner wrote:

That's a good example of where the mean value can be misleading.

My normal daily travel is, I guess, less than 20 miles. But one
day last week it was 450 miles. I need a car that can do both.

That is more than twice the safe recommended daily journey length.
I have known travelling salesmen fall asleep on the way home doing
those sorts of distances.

Really? That's about 7-8 hours. Truckers do that without breaking a
sweat. I do it when I drive to TN or back.

They are proffesional drivers. The big difference is that an engineer or
salesman is expected to do at least a half a days work in addition to
his travel time to and from the client.

That took ~12 hours, including stops in the middle of nowhere to
relax and snooze. The latter would not have been possible in a
petrol forecourt.

The chargers I looked at on motorway services claimed to boost the
battery back to 80% range capacity in 20-40 minutes.

Doesn't that rather depend on the size of the battery???

Not as much as you might think since apart from a few outliers all the
car batteries are similar capacities and the charger adapts to them.

Charging is rated in kW. I don't see how any other metric is useful
or practical. Some people try to rate them as MPH. But that also
depends on the car.

They are remarkably vague about the actual kW rating beyond advising
that people with pacemakers should stand well back. eg

https://www.ecotricity.co.uk/for-the-road/charge-your-vehicle

Then there are electric showers and electric ovens, which have
dedicated lines run from the fuse box, and are rated up to 7kW.

Modern houses may be different, but in the UK many houses are
100-200 years old and will have been rewired in the 50s or 60s.

I think it is an average vs peak issue here. Peak household load
can go as high as its main fuse permits 40,60 or 80A. The nominal
average daily load that a household presents is usually estimated
at 6-10kWhr.

Lower numbers being favoured by green campaigners as it makes how
many houses a wind farm can supply sound bigger.

10 kWh per day in the winter seems very light. I've used $60 worth
of electricity in three days when the nights were really cold.

In the UK no-one with any sense uses electricity for space heating and
about half don't use it for cooking either. Mains gas is the method of
choice for hot water and CH and is typically a 10-20kW unit in its own
right the electricity used is only for the CH pump about 200W max.

It strikes me that the old style electric cookers and rigid timing of
dinner in the 1950's puts a fairly hard bound on what the local grid was
designed for as at least 4kW peak per household at that period.

Where I live oil or solid fuel is the default for heating since we have
no mains gas service in the village (despite being in the dead zone of
one of the UK's highest pressure trunk gas mains).

--
Regards,
Martin Brown

 

[Chris Jones]

On 16/06/2019 14:00, Rick C wrote:

On Saturday, June 15, 2019 at 7:43:03 PM UTC-4, Winfield Hill wrote:
tabbypurr@gmail.com wrote...

On Saturday, 15 June 2019, Rick C wrote:

But I'm being told there are two problems with that.
One is that distribution is sized for an average of
2 kW consumption per household in many older areas ...

So are these two problems being presented realistically?

Bogus. I can't believe houses don't have enough
current capacity (2kW/230V = 9A) to run 1.5kW
microwave ovens, dishwashers, washers, electric
dryers, lights, TVs, HVAC, and a few electric
water heaters. In my visits to England, they
even had heated towel racks in their bathrooms.
A household without those basic amenities isn't
going to be buying EV cars anyway.

I was surprised how common it is in the UK to have instant electric
water heaters for showers, often 10kW or more. Here is a typical example:
https://www.screwfix.com/p/mira-sprint-multi-fit-white-10-8kw-electric-shower/257fr

 

[Martin Brown]

On 16/06/2019 04:50, Rick C wrote:

On Saturday, June 15, 2019 at 6:37:03 PM UTC-4, tabb...@gmail.com
wrote:
On Saturday, 15 June 2019 21:05:31 UTC+1, Rick C wrote:

To mitigate this a ground rod at the house is required which in
many cases is prohibitively expensive to install with an
adequately conductive path.

not really, nothing expensive about them. Where impedance is high
one uses an RCD - but those are universal now anyway.

So why didn't those guys tell me about the RCD solution? That's what

Perhaps they are not as expert as you give them credit for.

we call a GFCI I believe, trips on unbalanced current in neutral and
ground, right?

It trips if the flow of current in the Live and *Neutral* do not balance
out to within some fairly tight tolerance typically 10mA, 30mA or 50mA.

IOW any current escaping to Earth means it trips.

So are these two problems being presented realistically?

I'm also being told it will be a huge problem to provide enough
charging capability for the many potential EV owners who park on
the street or in public facilities. I expect it is practical to
install curb side and parking lot outlets with some outlay which
is small, in fact tiny compared to the cost of a car. But I
kinda have to take them at their word for that one.

Rick C.

Everything I've heard indicates that kerbside charging would be
very expensive to install in quantity. The infrastructure to
support iy isn't there.

You sound like you can address this rationally. Can you verify the 2
kW per house typical usage? That seems awfully low. I understand

On average it may well be right since space heating and about half of
all cooking is done by mains gas or kerosene. My own house only the
computers, kitchen appliances and electric lights are on electricity.

The annual UK national average is claimed to be about 4kWhr/day. See

https://www.ovoenergy.com/guides/energy-guides/how-much-electricity-does-a-home-use.html

coffee makers in the UK are designed to use the full 13 amps on a 240
volt circuit. That is 3 kW. So with a few other things drawing
similar loads I don't see how a distribution system designed for 2 kW
could ever suffice. Is this one of those things where the 2 kW
figure only applies to older neighborhoods? Any idea of what
percentage of the homes are like this?

The 2kW number is just hopelessly wrong! When the 1960's estates were
built night time Economy 7 electric central heating was all the rage
(the infamous nuclear electricity too cheap to meter promise) so the
distribution network in towns would have been sized accordingly.

Even prior to that the national grid system must have been designed to
handle electric cookers all being run at roughly the same time to cook
evening meals. They are hardwired because they are 6kW heating elements
(but again only on for a proportion of the time). Some modern designed
cookers will plug into a 13A socket being less than 3kW peak load.

I have to acknowledge that if this 2 kW number is correct and a large
fraction of homes in the UK receive such meager distribution, home EV
charging of any significant fraction of the cars would be impossible.
Otherwise adding a simple 13 amp outlet accessible to the EV would
suffice for charging up to 150 miles per night or more.

It is a time average. The distribution network can handle a lot more.
Electric 10kW flash heaters for instant hot water and showers are quite
common here. The duty cycle they are used for makes all the difference.

Same with kettles. It is a 3kW load but only for a couple of minutes.

--
Regards,
Martin Brown

 

[Winfield Hill]

Cursitor Doom wrote...

Rather than have guessing games among Americans as to
what the situation in the UK is, just ask the Brits direct!

Well, R.C. was told, so we'll just have to leave it at that.


--
Thanks,
- Win

 

[Cursitor Doom]

On Sun, 16 Jun 2019 15:09:11 +0100, John Rumm wrote:

[...]

Thanks, John. Nice to have advice from someone that actually knows what
they're talking about for a change.



--
Leave first - THEN negotiate!

 

[Tom Gardner]

On 16/06/19 09:53, Rick C wrote:

On Sunday, June 16, 2019 at 4:18:06 AM UTC-4, Martin Brown wrote:
On 15/06/2019 21:05, Rick C wrote:
I'm being told EV charging will be a lot more difficult in the UK than it
is here in the US.

I looked at the typical daily cycle and they have some 10 to 20 GW
between the peak and minimum each day with resonably flat consumption in
the trough. That will allow off peak charging of a third of the 30
million vehicles for 50 miles.

The problem is that charging parked cars during the day will coincide with
peak industrial demand and supply is already so tight during winter that
they have had to pay major industrial users to drop off to avoid rolling
blackouts. Prevarication over new nuclear build hasn't helped.

What will allow charging during the day is increased electric production from
renewable sources. Solar is getting cheap enough that it is profitable to
install it on a mass scale... although may not so much in the UK which is
more northern than anyplace in our lower 48. But it won't be long before
that is true in the UK as well. Please don't go off about cloudy days and
such since EVs don't need charging every day for most people and solar still
produces reduced amounts of energy even on cloudy days.

Cloudy days are a noticeable problem.

Short days are even more of a problem.

So some charging
will be supportable in the day time with out impact. Just give it a few more
years. From what I'm hearing EVs aren't very popular in the UK for now
anyway.


Charging overnight would work but then the generating capacity would have
to run flat out on a continuous basis.

And that is a good thing. The UK has gotten themselves in a bind by not
expanding their capacity enough.

Yup. We have <5% excess generating capacity, so if two
major plants go offline unexpectedly, there will be
problems. And engineers in the generating industry
know that, but they don't control the finance and don't
control the politics of NIMBYism.

So they will certainly be doing something
about that. In the mean time night time charging won't come anywhere near
capacity for likely some 10 years or more. If the UK can't figure it out by
then, well... there's no hope for them.

Yup, it is beginning to feel that way.

It breaks my heart, but I've advised my daughter to try
to find a way to emigrate.

But I'm being told there are two problems with that. One is that
distribution is sized for an average of 2 kW consumption per household in
many older areas (which they seem to have a lot of). This clearly makes
it hard to charge EVs overnight at just 3 kW which otherwise would be
fine for a typical user. In this case it would require replacement of a
lot of distribution cabling.

The distribution isn't quite that bad. It can cope with the likes of 3kW
kettle loads on almost simultaneously in 80% of households when there is a
major football final on at half time or a wimbledon final ends. But they
have to prepare for it.

What does that mean, "they have to prepare for it"? What can you do to beef
up distribution capability? The problem isn't generation or transmission
typically. It's the local residential distribution.

Actually, this may not be an issue in the UK at all. In many parts of the US
we use heat pumps. The distribution can handle 10-15-20 kW furnaces kicking
on all night when the weather gets too cold for the heat pump to work. My
concern has been that a 7 kW *continuous* load will be added in a significant
portion of homes without coordination of timing.

My understanding is that the UK doesn't use heat pumps with electric back up.

Correct. Residential premises don't use heat pumps
running in either direction.

The total demand is lowest at night, but what about residential demand, does
that go up significantly on winter nights?

Yes it does go up in winter. You can see the last annual
graph at http://www.gridwatch.templar.co.uk/ but bear
in mind that last winter was notably mild. Cold winters
are much worse.

The big problem is that there is nothing like enough electricity generating
capacity to provide all the extra power needed.

Bzzzz! Sorry, you lose. But please play again. You should have been
listening rather than playing those old 78 rpm records in your head. Excess,
idle capacity at night can very adequately charge enough EVs to be a third of
your entire fleet of vehicles. That won't be fully utilized for some years
to come.

Scandalously, we have <5% excess generating capacity.

I'm also being told it will be a huge problem to provide enough charging
capability for the many potential EV owners who park on the street or in
public facilities. I expect it is practical to install curb side and
parking lot outlets with some outlay which is small, in fact tiny
compared to the cost of a car. But I kinda have to take them at their
word for that one.

Street parking will be the killer for electric vehicles in the UK. Imagine
how bad it would be with trailing cables running across the pavement
(footpath) every car length in a country where people do still routinely
walk between nearby locations. This is a daytime google street view - you
have to imagine it with a solid wall of cars parked on either side of the
street and with no preference as to where you park.

Yes, for this to work outlets will be needed at the curb. Not an
insurmountable obstacle.

Insurmountable? No.

Very significant to the point of being impractical, yes.

But gauging from the seemingly unremitting
resistance I encountered in the UK group I was discussing this with, there
won't be much progress any time soon on this matter.

Correct.

Although, I see about half these cars are in driveways. Install an outside
outlet or two on each of these homes and you are halfway there to charging at
home!

Not in my road, not in many roads.

 

[Winfield Hill]

Martin Brown wrote...

A helicopter with a sniffer flies along it every fortnight.

I hope it's buried under several meters of cement.


--
Thanks,
- Win

 

[Martin Brown]

On 16/06/2019 15:11, Tom Gardner wrote:

On 16/06/19 13:08, Martin Brown wrote:

Where I live oil or solid fuel is the default for heating since we
have no mains gas service in the village (despite being in the dead
zone of one of the UK's highest pressure trunk gas mains).

The Nigerians have invented solutions to that, as
occasionally seen on the news.

It would be very exciting if it were ever breached as the operating
pressure is never less than 60bar and usually 80-90bar.

A helicopter with a sniffer flies along it every fortnight.

--
Regards,
Martin Brown

 

[Tom Gardner]

On 16/06/19 09:18, Martin Brown wrote:

Street parking will be the killer for electric vehicles in the UK. Imagine how
bad it would be with trailing cables running across the pavement (footpath)
every car length in a country where people do still routinely walk between
nearby locations. This is a daytime google street view - you have to imagine it
with a solid wall of cars parked on either side of the street and with no
preference as to where you park.

https://www.google.co.uk/maps/@54.5679098,-1.2259691,3a,75y,152.73h,90.68t/data=!3m5!1e1!3m3!1scmSICc2Tq98xoHWefBLBwA!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3DcmSICc2Tq98xoHWefBLBwA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D128.31041%26pitch%3D0%26thumbfov%3D100

That's good compared to my road in similarly leafy suburbs.

You don't get to park in front of your own house in street parking it is first
come first served. Leads could be trailing for up to 30m.

Currently I'm parked 50m away, it has been 200m away and/or
on the other side of the road and/or across a busy road.

And then there are people living in houses converted into
flats.

There are chargers for Teslas and some other brands on motorway service stations
but they are quite coy about their capabilities. I am actively considering an
electric car now that diesel is out of fashion. Figuring out if I can cover the
distances I need sensibly is a part of that.

EVs would do for many of my journeys, but, crucially,
not for all. Having a hybrid for some journeys is not
practical.

And the effect of hills shouldn't be neglected, particularly
if you live at the top of a hill and travel to the bottom
of the valley.

 

[Martin Brown]

On 16/06/2019 14:18, Winfield Hill wrote:

Cursitor Doom wrote...


Rather than have guessing games among Americans as to
what the situation in the UK is, just ask the Brits direct!

Well, R.C. was told, so we'll just have to leave it at that.

The number he has might well be right as a time average across a year
for a household. Typical numbers for various sorts and sizes of UK house
are online here in terms of energy use in kWhr per household per year.

It is about 3-4MWhr per year per household or 8-11kWhr/day on average.

That translates to a 300-500W average daily load which seems a bit high
to me. My own daily peak load is about 350W average and night time base
load is well under 100W unless I am running something on the computers.

Interesting that several green sites quote the 6kWhr/day figure when
working out how many homes a new green energy PV farm can supply.
(at least when the sun is shining or the wind blowing hard enough)

But I am fairly sure that the distribution system is good for delivering
considerably more than that as peak transient load without any problems
at all. It happens with 3kW kettles at half time every cup final day.

They have to prep the generating system ready for the exact moment and
then engage the rapid response kit and pumped storage at full tilt.

--
Regards,
Martin Brown

 

[Tom Gardner]

On 16/06/19 13:08, Martin Brown wrote:

In the UK no-one with any sense uses electricity for space heating and about
half don't use it for cooking either. Mains gas is the method of choice for hot
water and CH and is typically a 10-20kW unit in its own right the electricity
used is only for the CH pump about 200W max.

The government (and I use that term loosely) is making
noises about preventing gas being supplied to new-build
housing estates.

Where I live oil or solid fuel is the default for heating since we have no mains
gas service in the village (despite being in the dead zone of one of the UK's
highest pressure trunk gas mains).

The Nigerians have invented solutions to that, as
occasionally seen on the news.

 

[John Rumm]

On 16/06/2019 10:42, Cursitor Doom wrote:

Rather than have guessing games among Americans as to what the situation
in the UK is, just ask the Brits direct!



On Sat, 15 Jun 2019 13:05:26 -0700, Rick C wrote:

I'm being told EV charging will be a lot more difficult in the UK than
it is here in the US.

I looked at the typical daily cycle and they have some 10 to 20 GW
between the peak and minimum each day with resonably flat consumption in
the trough. That will allow off peak charging of a third of the 30
million vehicles for 50 miles.

That does rather assume there is not also a move to shift domestic
heating away from gas or oil to electric. We would certainly need more
generating capacity for any significant shift.

But I'm being told there are two problems with that. One is that
distribution is sized for an average of 2 kW consumption per household
in many older areas (which they seem to have a lot of). This clearly
makes it hard to charge EVs overnight at just 3 kW which otherwise would
be fine for a typical user. In this case it would require replacement
of a lot of distribution cabling.

Distribution networks are sized based on statistical models - so they
will calculate an average load over 24 hours to assess total demand.
However they do also anticipate significantly higher peak demands. New
properties are typically built with a 24kW electrical supply (1 phase,
100A, 240V). Older properties may have 80, 60 or in some cases only 40A
supplies. Typical home charging stations will run at 6kW, although those
with smaller EVs may opt to use a 13A (~3kW) charging lead plugged into
a socket. As EV battery capacities grow this kind of charging solution
may become less practical for some.

The other is that many individual homes are on PME circuits where no
separate ground is provided to the home, only the neutral.

PME (Protective Multiple Earthing) distribution systems supply the
property with a "PEN" conductor - Protective Earth and Neutral. This is
the main neutral as derived at the substation - however as its name
suggests it is bonded to earth at the substation, and then at regular
intervals along the distribution network. Its the preferred solution
for new supplies since it delivers a reliable and low impedance earth
path. Many older properties however will have TN-S earthing systems,
(i.e. separate earth delivered from the sub station to the property).
Older rural properties may well have no earth supply from the network at
all (TT systems)

For more detail see:

http://wiki.diyfaq.org.uk/index.php/Earthing_Types

This neutral
is bonded to water pipes and any other exposed metal that could be
grounded my any means, like an old radiator heating system. This is
considered safe since even if the neutral to the home opened there would
be no shock hazard since there is no ground to make contact with as the
grounds in the house are all at neutral voltage.

Generally more caution is used when exporting a PME earth to outside
circuits. The risk of neutral disconnection (and not line also) is
considered a fairly low likelihood event. However precautions taken
typically include extending the equipotential zone to where you are
exporting power. This is not ideally suited for EV charge points outside.

This does make it hard
to use electricity outside where you could contact a true earth ground
and suffer electrocution with any grounded appliance. To mitigate this
a ground rod at the house is required which in many cases is
prohibitively expensive to install with an adequately conductive path.

No not really. In many cases you simply convert to TT with local RCD
(GFCI). Hence any ground rod only needs a stable earth impedance under
the low hundreds of ohms, and that is relatively easy to achieve.

See:

http://wiki.diyfaq.org.uk/index.php/Taking_electricity_outside#Exporting_an_earth

Note also that there are specific additional rules for EV charging point
protection (special classed of RCD etc) designed to mitigate some of the
perceived problems.

So are these two problems being presented realistically?

I'm also being told it will be a huge problem to provide enough charging
capability for the many potential EV owners who park on the street or in
public facilities. I expect it is practical to install curb side and
parking lot outlets with some outlay which is small, in fact tiny
compared to the cost of a car. But I kinda have to take them at their
word for that one.

Street charging is a more difficult problem to solve without significant
new infrastructure. Hopefully at some point there ought to be a larger
network of fast chargers that can be used to charge on demand, rather
than overnight. Making for something closer to the current normal
practice of stopping off at a filling station to refuel.


--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

 

[Tom Gardner]

On 16/06/19 09:58, Martin Brown wrote:

On 16/06/2019 08:15, Tom Gardner wrote:
On 16/06/19 05:16, Rick C wrote:
On Saturday, June 15, 2019 at 9:23:42 PM UTC-4, ke...@kjwdesigns.com wrote:
On Saturday, 15 June 2019 13:05:31 UTC-7, Rick C  wrote:
I'm being told EV charging will be a lot more difficult in the UK than it
is here in the US.

I looked at the typical daily cycle and they have some 10 to 20 GW
between the peak and minimum each day with resonably flat consumption in
the trough.  That will allow off peak charging of a third of the 30
million vehicles for 50 miles.

The average car mileage in the UK is about 8,000 miles per year, even
allowing for increased usage during weekdays it probably only amounts to
25-30 miles per day to recharge. Not 50 miles.

That's a good example of where the mean value can be misleading.

My normal daily travel is, I guess, less than 20 miles. But one
day last week it was 450 miles. I need a car that can do both.

That is more than twice the safe recommended daily journey length. I have known
travelling salesmen fall asleep on the way home doing those sorts of distances.

Yes indeed, and so have I.

I was surprised at how well I held up, particularly due
to the unseasonable weather and that I went on the
Wainfleet-All-Saints bypass, of current front page
news fame!

I was fully expecting to have to doze for an hour at
one or two service stations, but to my surprise it
wasn't necessary.

That took ~12 hours, including stops in the middle of nowhere
to relax and snooze. The latter would not have been possible
in a petrol forecourt.

The chargers I looked at on motorway services claimed to boost the battery back
to 80% range capacity in 20-40 minutes.

IIRC the first major standardisation was to 240V with 5A
sockets. In the 50s/60s most places were rewired to 13A
sockets. I remember as a kid (early 60s) having to change
mains plugs when I took toys to my friend's house because
they still had the old plugs.

2A, 5A plugs and 16A (-o-) plug socket for the kettle in the kitchen. One of my
college rooms still had those 2A sockets in places.

I don't remember seeing those 2A plug/sockets.

OTOH I have seen mains wiring consisting of a two
core cable covered in a lead sheath. The latter was
the protective mains earth, and junction boxes
gave/give me the screaming heebie-jeebies. Fortunately
it wasn't connected to any live circuits.

Electric kettles in UK usually have a 3kW heating element (240V @ 13A) and
it is a well known phenomenon that during intervals of popular TV programs
a large percentage of the population goes to "make a cup of tea" causing a
huge increase in electrical consumption.  The system can already tolerate
that. (https://en.wikipedia.org/wiki/TV_pickup)

Also the 3kW of power available from a normal outlet means that charging is
significantly faster than in the US. It would provide 10-12miles/hour for
most EVs. ~100 miles overnight, without any special wiring.

Yes, US outlets can provide 1.5 kW.  Can UK outlets provide a full 13 amps
continuously?  I think someone told me that which is different from the US
where continuous loads have to be derated to 80%, so 12 amps at 120 volts.

Yes, individual sockets are rated to deliver 13A continuously.
However, they are usually on ring mains which have 5A (lighting)
or 30A (sockets) thermal fuses.

Then there are electric showers and electric ovens, which have
dedicated lines run from the fuse box, and are rated up to 7kW.

Modern houses may be different, but in the UK many houses
are 100-200 years old and will have been rewired in the 50s
or 60s.

I think it is an average vs peak issue here. Peak household load can go as high
as its main fuse permits 40,60 or 80A. The nominal average daily load that a
household presents is usually estimated at 6-10kWhr.

Lower numbers being favoured by green campaigners as it makes how many houses a
wind farm can supply sound bigger.

You are lucky to find a green campaigner that understands
that kW != kWh. It is impossible to get them to answer
"if we install X GW of wind power, how much conventional
plant can we remove?".

Well, that's not quite true. They answer, but the answers
are invariably wrong.

 

[Tom Gardner]

On 16/06/19 11:14, John Larkin wrote:
> Teslas rarely show up at ski areas in the dead of winter.

Oh, picky picky picky

 

[Cursitor Doom]

On Sun, 16 Jun 2019 02:25:55 -0700, Rick C wrote:

If the UK can't build power generation in 10 years, I think there is no
hope for the UK. Maybe the Germans should have won the war. You would
not have any power shortage if they were running things.

Instead of making ignorant, offensive remarks, take the guesswork out and
check out the facts for once in your miserable life.

http://gridwatch.co.uk/



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[Cursitor Doom]

On Sun, 16 Jun 2019 02:41:27 -0700, Rick C wrote:

Let me repeat myself yet again. Charge at home, always have a full
battery in the morning and never have to drive to a busy, smelly, nasty
gas station again.

I thought you were referencing the situation specifically in the UK,
where access to charging, even if you own your own home, is frequently
impossible.




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[John Larkin]

On Sun, 16 Jun 2019 13:52:00 +0100, Martin Brown
<'''newspam'''@nezumi.demon.co.uk> wrote:

On 16/06/2019 04:50, Rick C wrote:
On Saturday, June 15, 2019 at 6:37:03 PM UTC-4, tabb...@gmail.com
wrote:
On Saturday, 15 June 2019 21:05:31 UTC+1, Rick C wrote:

To mitigate this a ground rod at the house is required which in
many cases is prohibitively expensive to install with an
adequately conductive path.

not really, nothing expensive about them. Where impedance is high
one uses an RCD - but those are universal now anyway.

So why didn't those guys tell me about the RCD solution? That's what

Perhaps they are not as expert as you give them credit for.

we call a GFCI I believe, trips on unbalanced current in neutral and
ground, right?

It trips if the flow of current in the Live and *Neutral* do not balance
out to within some fairly tight tolerance typically 10mA, 30mA or 50mA.

IOW any current escaping to Earth means it trips.

Do you get many false trips?

So are these two problems being presented realistically?

I'm also being told it will be a huge problem to provide enough
charging capability for the many potential EV owners who park on
the street or in public facilities. I expect it is practical to
install curb side and parking lot outlets with some outlay which
is small, in fact tiny compared to the cost of a car. But I
kinda have to take them at their word for that one.

Rick C.

Everything I've heard indicates that kerbside charging would be
very expensive to install in quantity. The infrastructure to
support iy isn't there.

You sound like you can address this rationally. Can you verify the 2
kW per house typical usage? That seems awfully low. I understand

On average it may well be right since space heating and about half of
all cooking is done by mains gas or kerosene. My own house only the
computers, kitchen appliances and electric lights are on electricity.

Kerosene? Yikes.

The annual UK national average is claimed to be about 4kWhr/day. See

https://www.ovoenergy.com/guides/energy-guides/how-much-electricity-does-a-home-use.html

coffee makers in the UK are designed to use the full 13 amps on a 240
volt circuit. That is 3 kW. So with a few other things drawing
similar loads I don't see how a distribution system designed for 2 kW
could ever suffice. Is this one of those things where the 2 kW
figure only applies to older neighborhoods? Any idea of what
percentage of the homes are like this?

The 2kW number is just hopelessly wrong! When the 1960's estates were
built night time Economy 7 electric central heating was all the rage
(the infamous nuclear electricity too cheap to meter promise) so the
distribution network in towns would have been sized accordingly.

Even prior to that the national grid system must have been designed to
handle electric cookers all being run at roughly the same time to cook
evening meals. They are hardwired because they are 6kW heating elements
(but again only on for a proportion of the time). Some modern designed
cookers will plug into a 13A socket being less than 3kW peak load.

I hate cooking on an electric range. Gas is great.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[John Larkin]

On Sun, 16 Jun 2019 09:58:55 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

On Sat, 15 Jun 2019 20:50:29 -0700, Rick C wrote:

I have to acknowledge that if this 2 kW number is correct and a large
fraction of homes in the UK receive such meager distribution, home EV
charging of any significant fraction of the cars would be impossible.
Otherwise adding a simple 13 amp outlet accessible to the EV would
suffice for charging up to 150 miles per night or more.

The maximum draw per single domestic socket outlet is 13A. HOWEVER, most
homes can legitimately have up to 60A -100A by taking a dedicated spur
off the house's consumer unit/distribution board. The general limit per
domestic installation is limited by the power co's fuse which is
generally 100A maximum. I'm sure that's plenty for even an American. ;-)

No one in the right mind would attempt to charge an EV from a 13A socket
(unless time was not a consideration.) ;-)

We have 30KW, 120-N-120 at 125 amps. We have gas too, so we use a tiny
fraction of that capacity.

120V outlets are good for 15A, I think. The clothes dryer socket is
240V, but it uses gas too.

Car charging would be possible but very inconvenient.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics