EV Charging in the UK

[Winfield Hill]

Tom Gardner wrote...

Official "notices of insufficiency" are regularly issued.

If smart metering is introduced, with peak-load pricing,
people will start finding ways to time their usage. We
don't have that here, but I wish we did.


--
Thanks,
- Win

 

[Tom Gardner]

On 16/06/19 17:36, Martin Brown wrote:

On 16/06/2019 17:14, upsidedown@downunder.com wrote:
If you add up the total nominal power output of all available units,
this is well larger than the annual peak load. However, running all
would be very expensive, so you try to optimize the power station
production mix at any time.

Not in the UK it isn't. Without the demand side industrial load shedding the
margin of generating capacity to anticipated winter load in cold weather it is
now touch and go as to whether the lights stay on.

The people I have talked to (at IET meetings) whose job it
is to keep the lights on explicitly state they know they will
not be able to keep them on. The only question is the extent
and duration of the cuts.

Since it would be politically unacceptable for peons with a
vote to be blacked out, companies and the economy will
suffer first.

 

[Tom Gardner]

On 16/06/19 17:14, upsidedown@downunder.com wrote:

On Sun, 16 Jun 2019 15:34:39 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

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.

I think you are mixing up concepts.

No, I am not.

Scandalously I am right.

That 5 % sounds about right as the running reserve or short startup
time (minutes) gas turbines to fulfill the N-1 criterion, i.e. to
allow the largest single unit (typically nuclear) dropping from the
net. There are time limits (like 30 min) how fast slower starting
power plants must be started to restore the N-1 condition. to allow
for the next largest unit dropping out.

No.

In any country there are different types of power plants, some are
expensive to build but cheap to operate, such as nuclear, other are
chap to build but very expensive to operate like natural gas aero
derived gas turbines (essentially jet engines). An emergency gas
turbine would be run for less than 100 hours including regular test
runs.

If you add up the total nominal power output of all available units,
this is well larger than the annual peak load. However, running all
would be very expensive, so you try to optimize the power station
production mix at any time.

All true, but regrettably it doesn't change the fundamental
point that we are very near to the limit.

Official "notices of insufficiency" are regularly issued.
The audience is those commercial customers that buy cheaper
electricity on the basis that supply won't be guaranteed.
Summary: such commercial customers should be prepared to
be cut off.

 

[Tom Gardner]

On 16/06/19 18:06, Winfield Hill wrote:

Tom Gardner wrote...

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.

I have that issue, but do my charging for a round
trip. What I lose in one direction, I get back
on the other.

I didn't know you had hills in Boston

More seriously, I know someone in Bristol that
can't/won't charge his EV fully overnight, since
he recharges the battery going downhill in the
morning.

Since I can't measure it, I really ought to
calculate X ft hillclimb equates to
- Y miles on the horizontal in zero wind
- ditto +25mph headwind / tailwind
- Z 0-30mph and 0-30-0mph transitions

In the UK, city driving fuel consumption is dominated
by the number of stop-starts in traffic; the open-road
fuel consumption is relatively unimportant.
For example, a Ford Fiesta: 34mpg urban,
57mpg extra-urban, 46mpg combined.

 

On Sunday, 16 June 2019 11:12:36 UTC-7, Rick C wrote:
....

Seems that regardless of the lack of consistency, any EV connection requires an earth rod with sufficiently low resistance. I'm willing to bet EVs are designed to be the same as double insulated tools so electrifying the body simply won't happen. But you still need the earth rod!
....

On all EV's all of the high-voltage circuitry, including battery and motors, are galvanically isolated from the chassis.

There is leakage detection from the HV circuitry to chassis to detect any faults and there are separate positive and negative HV contactors that are not engaged until after an initial fault check. Even if one of the contactors fails short the system is still safe.

The level 2 charger has an isolation barrier to the HV circuitry.

The EVSE used fr AC charging has a built-in RCD to detect other ground faults

kw

 

[Rick C]

On Sunday, June 16, 2019 at 9:18:55 AM UTC-4, 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.

It's not like we don't have any Brits in this group. Some have already contributed. I'm curious if this differs much in other countries. I think parts of mainland Europe may be similar. I'd be willing to bet Australia is not so similar, rather more like the US.

--

Rick C.

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On Sunday, 16 June 2019 10:47:26 UTC-7, Rick C wrote:
....

Whaaaa...? Battery sizes range from Win's very small, I don't know, 20 kWh? to 100 kWh in my Tesla. The majority of EVs on the road in the US are Teslas, can't say about the UK. Charging units are rated in kW, anything else is just fooling yourself.

....

Win's Prius Prime has an 8.8kWh battery - it is a plug-in hybrid with ~25 miles electric only range.

kw

 

[Rick C]

On Sunday, June 16, 2019 at 8:52:06 AM UTC-4, Martin Brown 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.

Seems that regardless of the lack of consistency, any EV connection requires an earth rod with sufficiently low resistance. I'm willing to bet EVs are designed to be the same as double insulated tools so electrifying the body simply won't happen. But you still need the earth rod!

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

kWh/day doesn't really tell you much. With 25 million homes that comes to 100 GWh per day or 4 GW average capacity. Assume that varies 2:1 during the day and has a peak of... maybe 8 to 10 GW? Compare to the range of 30 to 60 GW peak usage over the day depending on the season.

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.

Yeah, that makes sense to me.

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.

That it is a time average doesn't matter. EVs tend to be on for hours, so each EV has to be counted fully unless there is a way to essentially multiplex them in a coordinated fashion.


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

Exactly, so I can't dispute the 2 kW average number.

--

Rick C.

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[Rick C]

On Sunday, June 16, 2019 at 8:36:47 AM UTC-4, upsid...@downunder.com wrote:

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.

Those are entirely realistic numbers. My model X is the battle ship of the Tesla fleet and gets 3 miles per kWh. The model 3 can get 5 miles per. So 6 km/kWh should be no problem for most EVs. Here in the US the Nissan Kia has sold well for some years and there are a lot of them out there. Some have pretty small batteries, 50 mile range I think, but for around town that's fine.

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.

Who drives 240 km each day? I suspect that is no more than 1% of the population. For most people they can charge every night for a few hours and be topped off or they can go for a few days without charging and then charge all night once or twice a week. Someone posted a Google map link of a urban street to show all the cars on the curb. But when I explored a bit there were as many parked off the street right in front of the house as on the street. It looked like one house would have two or more cars often. They could rotate charging and have no problems.

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.

Yeah, even here that is an unusual commute.

EVs are coming to a driveway near you. If you don't want one, you can put up with the mess and expense of the oil leaking, gas guzzling, carbon spewing beast you are currently driving. I think it is Ford who is saying all their cars will be electric by some date. I bet the F150 is still gas for a long time though.

--

Rick C.

---+ Get 1,000 miles of free Supercharging
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[Rick C]

On Sunday, June 16, 2019 at 8:08:35 AM UTC-4, Martin Brown wrote:

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.

Lol, you are funny.

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.

Whaaaa...? Battery sizes range from Win's very small, I don't know, 20 kWh? to 100 kWh in my Tesla. The majority of EVs on the road in the US are Teslas, can't say about the UK. Charging units are rated in kW, anything else is just fooling yourself.

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

"Charging sessions usually last 45 minutes" So I don't know where you got the 20 minute number.

Tesla's batteries will accept their highest rate at around 20% capacity linearly tapering off in either direction. The new 250 kW chargers will shave some minutes off the charging time since you get faster charging from 20 to 50%. In addition it relieves the loss of charging rate when sharing a pair of chargers.

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.

I'm told there was a program to get people to use heat storage tanks which are powered at night and release heat all day. They have to be a significant power level.

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.

Yeah, I can't find any hard info on this figure for either the US or for the UK. One guy says the UK is 2 KW, but that just seems too low. They mentioned how when a team is in the finals and a commercial break comes on, the tea kettles are fired up and the grid has trouble keeping up. At 3 kW, all at the same time, it only takes a quarter of the homes to stress the entire grid!

--

Rick C.

---- Get 1,000 miles of free Supercharging
---- Tesla referral code - https://ts.la/richard11209

 

On Sunday, 16 June 2019 10:57:04 UTC-7, Rick C wrote:
....

Those are entirely realistic numbers. My model X is the battle ship of the Tesla fleet and gets 3 miles per kWh. The model 3 can get 5 miles per. So 6 km/kWh should be no problem for most EVs. Here in the US the Nissan Kia has sold well for some years and there are a lot of them out there. Some have pretty small batteries, 50 mile range I think, but for around town that's fine.
....

I think you mean the Nissan Leaf.

The original Leaf had ~24kWh battery (~21kWh usable) with an EPA range of 73 miles.

It is not the most efficient so it also only gets about 3-4mi/kWh.

Be careful about the various efficiencies quoted - all EVs display consumption from the battery on their internal instrumentation, it does not include charger or battery losses.

In the case of my Tesla M3 the displayed consumption is ~240 Wh/mi (4mi/kWh). The charger has only about 75% efficiency when powered by 120V so the actual consumption from the wall is about 3mi/kWh.

The charger efficiency from 240v is about 85-90%.

Your Model X is probably closer to 2.5mi/kWh when charging from 120v.

kw

 

[Rick C]

On Sunday, June 16, 2019 at 12:11:51 PM UTC-4, ke...@kjwdesigns.com wrote:

On Saturday, 15 June 2019 22:21:51 UTC-7, John Larkin wrote:
...
If you only drive a few miles a day in a regular car, you won't use
much gasoline so you won't Destroy The Planet. You can spend 5
minutes, every few weeks, filling up. That's just about the right
amount of time to squeegie the windows.

Myself and many other people prefer the driving experience with electric vehicles.

OMG! Driving my model X is such a joy! I had an S for a few days and that is much sportier with quicker handling, but I have to accordion to get into it. Seems the windshield rakes back pretty hard and my shoulders and head bump things.

It is not necessarily anything to to do with saving the planet, although that's a nice side benefit.

Normal charging is more convenient than with a gasoline cars as it is done while I sleep for a few seconds of plugging in when necessary.

It's also about a third the cost even in my huge model X, the worst fuel economy in the Tesla fleet.

If you drive long distances, charging an electric car becomes a
nuisance.

Agreed that requires more planning than with a gasoline car but eminently practical.

That depends on whether you want to plan ahead or just use the navigator in the car to tell you where to charge. I was thinking of going to a place in Kentucky once. That would have actually required planning since one route was lacking a charger in a location so there would have been a side trip needed. Go on the other main route and no problem. The only part that needs planning is what to do when you get where you are. Sometimes there aren't any convenient charging facilities and people's homes don't typically have anything but level 1 accessible. Hotels often have level 2, overnight charging though. Free too.

--

Rick C.

+--- Get 1,000 miles of free Supercharging
+--- Tesla referral code - https://ts.la/richard11209

 

[Rick C]

On Sunday, June 16, 2019 at 11:31:23 AM UTC-4, Cursitor Doom wrote:

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.

There is no point in continuing to discuss this with you. "Impossible" is a strong word. If that really applies in the UK, then you guys have some very seriously large problems. I have had posters from the UK talk like they don't expect any new generation capability to be built even in 30 years. What happened to the UK, one time ruler of the waves, breakers of the Enigma code? You guys can't even figure out how to install electric outlets???

--

Rick C.

-+++ Get 1,000 miles of free Supercharging
-+++ Tesla referral code - https://ts.la/richard11209

 

[Rick C]

On Sunday, June 16, 2019 at 11:06:14 AM UTC-4, Lasse Langwadt Christensen wrote:

søndag den 16. juni 2019 kl. 11.34.53 UTC+2 skrev Rick C:
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.


rules here are max 4.5hours then minimum 45 minute rest, max 9 hours total
then a 11 hour rest

About perfect for EV use. Charge overnight, drive 4.5 hours, charge while resting, 4.5 hours drive, lather, rinse, repeat.

--

Rick C.

-++- Get 1,000 miles of free Supercharging
-++- Tesla referral code - https://ts.la/richard11209

 

[Rick C]

On Sunday, June 16, 2019 at 10:34:42 AM UTC-4, Tom Gardner wrote:

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.

Are you saying there won't be viable solar generation in the UK? Your comments are a bit like Larkin's and Trump's, saying something without saying anything.

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.

None of that makes night time charging of EVs impractical. In fact night charging of EVs improves utilization and provides more profits to plow into building infrastructure.

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.

Really? I like what I've seen of the UK (TV mostly). It's not like you are only growing potatoes.

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.

I would be looking for a daily graph from the winter, not the winter average. Here...

https://energymag.files.wordpress.com/2014/02/daily-demand-copyright-2011-national-grid-plc-all-rights-reserved.jpg

Not a large increase from summer to winter, but a more significant evening peak. Night charging of EVs should not be started before 8 or 9 PM.

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.

Why exactly??? Everyone says this because they can't picture it. But they aren't looking at any real info, just picturing crews digging up streets and sidewalks with chaos and terror reigning. A charge point would be $1000 or maybe as low as $500 per when done in mass. I'm talking about a 13 amp connection. I guess a credit card reader would be needed, so a smart unit rather than a dumb outlet and $1000 per. So how much is a car? $30,000, $40,000? A one time cost of $1,000 seems small in that context, no?

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.

Ok, when you guys want to catch up, let us know. The US is pretty good at helping third world countries... ;-) Just kidding.

--

Rick C.

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[Rick C]

On Sunday, June 16, 2019 at 10:09:15 AM UTC-4, John Rumm wrote:

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.

Wouldn't it be rather pointless to burn fossil fuels inefficiently to produce electricity, then use the electricity to make heat? We do it in the US because many homes don't have gas and heating oil requires a tank which takes up space many homes don't have and is a bit of a bother requiring maintenance. It was only in the 80s or so that we started using heat pumps where before the electric utilities encouraged direct heating from the ceiling, floor or baseboard.

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.

What the incoming feed is rated for is not the issue. The important part is the distribution. You say they average a measurement, but this is done when the homes were built or power added. Now adding EV charging may be a significant additional load even at 13 amps. 13 amps will be more than adequate for most since it equates to about 150 miles in 10 hours or 210 in 14 hours. That's a lot more than either the typical or average use (mode vs mean).

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

Trust me, I am well versed in the various systems now. The TN-C with the PEN conductor is the one they say will require a new earth rod for any EV charging, by code. I had trouble correlating that will other electrical power used outside, but it seems they get away with that somehow even though it is not safe unless a separate earth is installed to make those outlets TT..

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.

Yeah, as in virtually impossible for portable tools that aren't double insulated.

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.

The fly in the ointment of that approach is the code specifically calls for EV charging to be TT, local earth with low impedance... or so I am told.

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.

Again, I can only go by what I am told. First it was TT is needed, then someone here said RCD so I went back to them with that and they said, not code! Now it sounds like you are saying a special RCD can be used with EVs?

That conversation and some others are being ended today by the moderators. I think it is wise, it wasn't really contentious, but some there didn't like being questioned. To me this is all just exploring to find the ultimately right answer, no ego or recriminations involved.

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.

Fast chargers have limitations. I don't think they will ever be as fast as filling a gas tank. This shifts the power consumption to peak times of the day, the worst thing you can do... literally, not to mention the huge number of rather expensive charging units needed.

Home and work charging is the way to optimally match the energy availability going forward. Solar in California is so abundant that the daily minimum is at noon. That is the time to charge EVs evening out the demand for other power facilities improving the economics.

https://cdn.vox-cdn.com/uploads/chorus_asset/file/6025169/caiso-duck-curve.png

Installing level 2 charging for virtually every home parking spot is not so enormous an effort that it's not practical. It's much cheaper than buying a car! Is everyone buying cars such a significant effort? We do it every day!

--

Rick C.

-+-- Get 1,000 miles of free Supercharging
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[Rick C]

On Sunday, June 16, 2019 at 12:41:39 PM UTC-4, Winfield Hill wrote:

John Rumm wrote...

Street charging is a more difficult problem to solve...

I can charge on the street, if I can park within two
car spots of my driveway. Apartment dwellers in a
crowded city have a problem. Several are like that
here at work, but they can charge up in our garage.

Once EVs become more popular and it starts to be an issue for people, businesses and apartments will start installing level 2 charging. They won't need to convert every spot, just enough to keep up with demand.

In California a law requires apartments and condos to allow a resident to pay to have a charger installed. At least that's a start.

--

Rick C.

+--+ Get 1,000 miles of free Supercharging
+--+ Tesla referral code - https://ts.la/richard11209

 

[Tom Gardner]

On 16/06/19 20:01, Rick C wrote:

On Sunday, June 16, 2019 at 10:34:42 AM UTC-4, Tom Gardner wrote:
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.

Are you saying there won't be viable solar generation in the UK? Your
comments are a bit like Larkin's and Trump's, saying something without saying
anything.

Define "viable".

Sufficient for all the purposes you imagine, e.g. charging
EVs overnight in winter in Scotland - no.

For solid physics/chemistry with solid numbers and
without meaningless adjectives, see the resource
lauded by *everybody* from The Greens to Big Oil:
http://withouthotair.com/

MacKay includes several options for the UK future,
without preferring any. But he does insist on solid
science and that the arithmetic adds up.

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.

None of that makes night time charging of EVs impractical. In fact night
charging of EVs improves utilization and provides more profits to plow into
building infrastructure.

You continue to ignore the parlous state of our electricity industry.

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.

Really? I like what I've seen of the UK (TV mostly). It's not like you are
only growing potatoes.

Why am I not surprised that your impression of the UK is
formed from watching TV programmes.

Come here, open your eyes.

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.

I would be looking for a daily graph from the winter, not the winter average.
Here...

https://energymag.files.wordpress.com/2014/02/daily-demand-copyright-2011-national-grid-plc-all-rights-reserved.jpg

Not a large increase from summer to winter, but a more significant evening
peak. Night charging of EVs should not be started before 8 or 9 PM.

Correct, since last winter was noticeably mild - as I
clearly stated.

There is more difference in normal winters, and
the difference should be understood in the context
of <5% energy generation margin.

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.

Why exactly??? Everyone says this because they can't picture it. But they
aren't looking at any real info, just picturing crews digging up streets and
sidewalks with chaos and terror reigning. A charge point would be $1000 or
maybe as low as $500 per when done in mass. I'm talking about a 13 amp
connection. I guess a credit card reader would be needed, so a smart unit
rather than a dumb outlet and $1000 per. So how much is a car? $30,000,
$40,000? A one time cost of $1,000 seems small in that context, no?

Come here and have a look; see for yourself.

You seem to be basing your understanding of the UK on
TV programmes. What would you think of someone that
based their understanding of the US on Baywatch and
Midsummer Murders and NCIS and The Wire and The West
Wing?

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.

Ok, when you guys want to catch up, let us know. The US is pretty good at
helping third world countries... ;-) Just kidding.

In some respects the US is a third world country. Just kidding.

 

[Rick C]

On Sunday, June 16, 2019 at 1:41:15 PM UTC-4, Tom Gardner wrote:

On 16/06/19 18:06, Winfield Hill wrote:
Tom Gardner wrote...

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.

I have that issue, but do my charging for a round
trip. What I lose in one direction, I get back
on the other.

I didn't know you had hills in Boston

More seriously, I know someone in Bristol that
can't/won't charge his EV fully overnight, since
he recharges the battery going downhill in the
morning.

Since I can't measure it, I really ought to
calculate X ft hillclimb equates to
- Y miles on the horizontal in zero wind
- ditto +25mph headwind / tailwind
- Z 0-30mph and 0-30-0mph transitions

In the UK, city driving fuel consumption is dominated
by the number of stop-starts in traffic; the open-road
fuel consumption is relatively unimportant.
For example, a Ford Fiesta: 34mpg urban,
57mpg extra-urban, 46mpg combined.

That's a big difference with electrics. They recharge on slowing down so get about 80% back to the motor through the battery. That is one of the reasons why they are much cheaper to fuel.

--

Rick C.

+-++ Get 1,000 miles of free Supercharging
+-++ Tesla referral code - https://ts.la/richard11209

 

[Rick C]

On Sunday, June 16, 2019 at 1:04:32 PM UTC-4, Winfield Hill wrote:

Tom Gardner wrote...

Official "notices of insufficiency" are regularly issued.

If smart metering is introduced, with peak-load pricing,
people will start finding ways to time their usage. We
don't have that here, but I wish we did.

I've mentioned that here before. I think it may require more than just off-peak charging. To avoid local overloads from a concentration of BEVs charging at higher rates than just level 1, it may require staging the charging.. The cars are already pretty smart so they can indicate to the wall unit how much charge they need and when the owner wants to use it next. The wall unit can coordinate through the utility to get the car charged by the indicated time.

My concern is that adding a 30 amp circuit to each home in a neighborhood can add enough capacity to overload it compared to the design capacity. Think of a ferry boat. It is designed to hold some number of cars and some number of people, mostly a single passenger per car, with a safety factor. Then people start driving EVs with an extra 500 or 1,000 lbs each and one day the cars happen to be full of people and the ferry wallows and sinks.

The ferry operator won't let the boat sink. He will be on top of it enough to realize he has to limit the number of cars on such a day. A utility can't go into a neighborhood in the coldest day of the year and tell people they have to turn off their heat pumps or not charge their cars... unless, the put the cars on a coordinated network so they can be staged.

Utilities tried this in some places with home heating systems. So clearly there is potential for a problem. I want them to think about the EV problem and take action on the coordination of home charging before it creates problems and they solve it by upgrading equipment and getting the public service commission to allow them to raise the rates.

--

Rick C.

+-+- Get 1,000 miles of free Supercharging
+-+- Tesla referral code - https://ts.la/richard11209