400kW charger - how many of these on a typical local network ?

I'm not saying that we won't need a country-wide network of charging points, but I think we're in danger of assuming too much use of them by thinking of the use that fuel pumps get.
 
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I'm not saying that we won't need a country-wide network of charging points, but I think we're in danger of assuming too much use of them by thinking of the use that fuel pumps get.

Yes, I take your point. I think that the greatest demand for en-route recharging will be on the motorways and main A routes, and there we need the very fastest chargers to minimise delays and queues.
 
Rather than speculate about what others must surely do, if your car magically had a full tank of petrol or diseasel every morning you woke up, how many times so far this year would you have needed to visit a filling station?

Rather than refer to the point under discussion BAS brings up something that is totally and utterly irrelevant, and then he wonders why people get annoyed at him.

For the sake of clarity, I will explain further. I am not speculating at all but drawing a logical conclusion. If the average journey is 10 miles and cars on average do an absolute minimum of 21 miles a day then some journeys have to be longer than 10 miles*. As I have experience of my own life and that of many friends & family I know that people who make lots of short journeys (commuting, shopping, etc) also do longer journeys. As @davelx points out, he needs a range of at least 250 miles. My wife visited her parents for the day last week, a round trip of 190 miles.

As to BAS' point about the tank being full every morning, about the only accurate word is 'magically'. Magic is the only way that an EV can be kept fully charged nationwide.

People are not limited to journeys on one day that is 50 miles out and 50 miles home. They go to visit friends / family who may well be c. 100 miles away. Even if they can plug an EV in to a 13 amp socket it will not fully recharge unless they stay overnight.

If someone visits a place of interest of whatever sort (nice garden, historic house / building, piece of coast, specialist retailer, etc) they may well travel more than 50 miles to get there and they are extremely unlikely to be able to recharge it on site.

People go on holiday by car and easily travel 200 miles in a single day to get to their destination.

*To forestall BAS, mathematically those numbers can be reconciled by someone making two 10 miles journeys, e.g. commuting to work, every single day of the year. I will leave the probability of that happening as an optional exercise for the reader.
 
Rather than refer to the point under discussion BAS brings up something that is totally and utterly irrelevant, and then he wonders why people get annoyed at him.
It is not totally and utterly irrelevant.

It is not even slightly irrelevant.

It is, in fact, a vital factor to consider.

And all I asked you to do was to consider it, but you'd rather argue that it is irrelevant to think that people will never do any charging at home and will always need to visit public charging locations as often as they currently visit petrol stations.

For the sake of clarity, I will explain further. I am not speculating at all but drawing a logical conclusion. If the average journey is 10 miles and cars on average do an absolute minimum of 21 miles a day then some journeys have to be longer than 10 miles*.
Indeed they do.

But how many are over 100 miles?

How many over 200?


As I have experience of my own life and that of many friends & family I know that people who make lots of short journeys (commuting, shopping, etc) also do longer journeys. As @davelx points out, he needs a range of at least 250 miles.
How often does he need such a range?
How typical or atypical is he in needing it as often as he does?

My wife visited her parents for the day last week, a round trip of 190 miles.
Does she do that every day? Once a week? Once every two? Just now and then?

Do people go on holiday every day?

Contrary to what you assert, these issue are extremely germane to the question of what kind of network of public charging points we are going to need. Plus, as I've said before, a total switch to using EVs will probably need to be accompanied by a total change in the way we own and use vehicles. It wasn't that long ago that for the vast majority of the population a journey of hundreds, or even several 10's of miles in one day could only be done by train. And it's not even 200 years since nobody could travel 2-300 miles in one day, no matter how rich they were.
 
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Every cycle of dis-charge and re-charge reduces the capacity of the battery.

How many miles can a battery provide before re-charging has degraded it to be beyond sensible use.

100,000 miles ?. If the battery is treated well that is ( according to one EV manufacturer ) a conservative estimate.

Or could be be as low as 25,000 miles with a very much reduced range per re-charge after 10,000 miles. ?

One overvolt re-charge can all but destroy a battery. Will all public re-charging points be able to recognise the type of battery in the vehicle and set the maximum voltage acccordingly to avoid damaging the battery ?.
 
One overvolt re-charge can all but destroy a battery. Will all public re-charging points be able to recognise the type of battery in the vehicle and set the maximum voltage acccordingly to avoid damaging the battery ?.

There is communication (Control Pilot, IEC 61851-1) between the car and the charge-point - the car controls the charging process. The battery is usually about 400V DC. An SMPS is used, either on-board or in the charge point, to generate the required charge voltage and current.
 
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I'm not saying that we won't need a country-wide network of charging points, but I think we're in danger of assuming too much use of them by thinking of the use that fuel pumps get.
Yes, but ...
You are making the same assumption, that "magically" everyone can have a full battery each morning. I would suggest that there are more people for whom that will never be more than wishful thinking than there are people for whom it could be correct. It's easy to say "I'm alright jack, tough if you live on a terrace with no parking - you'll just have to move" - but that ignores the practicality for a very very large number of people. I'd even go so far as to suggest that many of those people are also some of the ones who could make best use of an EV. Think of all those blocks of flats in towns/cities with naff all parking ?
So, can't charge at home unless you are REALLY lucky in getting to park close enough to plug in. Charge at work ? Ha, fat chance for the vast majority. So that really leaves charging while you do the weekly shop, or something similar. So here's a practical exercise for you, have a look at the car park for your local supermarket (ASDA, Tesco, whoever you have locally) and see how many cars are there when it's a moderately normal time to be shopping.
Now imagine that, say (picking a random number from the air) half of them were EV and half of those need charging. Lets say your weekly shop is a couple of hours so can use (say) a 25kW charger. Looking at my local ASDA, there must be a few hundred cars there a lot of the time - so lets say 50 of them want to charge. 50 x 25 = 1,250 kW = 1.25 MW for a single supermarket. At the same time, there'll be a similar number of cars at Tesco, and at Morrisons, less at each Aldi and Lidl (but there's several of them).
But I can't see anyone putting large numbers of charging points in like that. More likely that there'll be a token handful at best - but maybe higher powered. So you arrive at ASDA to shop, but you can't charge because all the chargers are in use - and even though some of them might be finished, the owner won't be coming out and moving the car before they've finished their shop.

Now, how many miles ?
Well if the commute is 10 miles then that's 100 mile/week just for the commute. Add in a few short leisure trips and it's easy to reach (say) 200 miles - optimistic for most of todays EVs. And BTW - what is the REAL range of todays EVs in this sort of weather when the users need lights and (presumably electric) heaters ?
Then the longer journeys. I would put it at (for us) maybe once a month when we'd need that sort of range or more in one trip. So unless you are guaranteed the ability to charge en-route, then an EV won't hack it as your only car. Note that I said guaranteed ability to charge, not presence of a charger. Not much use if there is a charger (or two, or three, or ...) but they are already in use and there's a queue - and you aren't planning for a long stop. Even if you are planning a break - do you have to keep popping out (most aren't where you can see them from the cafe or whatever) to see if the charger has become free AND no-one else has nabbed it in the meantime ? And if you can see the charger from the cafe, will it be like this ?
 
So - what is the plan for when they stop making IC cars?

so lets say 50 of them want to charge. 50 x 25 = 1,250 kW = 1.25 MW for a single supermarket.
1l of petrol is 9.5kWh, 1l of diesel is 9.9 (https://en.wikipedia.org/wiki/Energy_density#Energy_density_in_energy_storage_and_in_fuel).

If we use the less onerous petrol figure, and assume that a pump transfers 1l/s, , that makes each pump a 9.5kWh/s, i.e. 34.2MW appliance. If you want to use a 30% efficiency factor, then it's a 10.26MW one.
 
It is not totally and utterly irrelevant.

Sorry but it is. You are, or at least seem, so wrapped up in your own opinion I suspect that you don't even know what the actual point was and so cannot see why what you said was irrelevant.

@flameport said that hardly anyone ever drives more than 100 miles in a day and therefore a range of 100 miles is sufficient. He based this on a flawed use of statistics. For his comparison (to a range of 100 miles) he used the mean journey distance of 10 miles whereas the correct comparison is against the median.

I have no idea what the median is but, as I showed, it has to be quite a bit greater than 10 miles. That is all I said. What you said was not at all relevant to this. What you said may or may not be relevant to the topic of EVs but it did not relate to what I said and so should not have been posted in reply to me.
 
@flameport said that hardly anyone ever drives more than 100 miles in a day and therefore a range of 100 miles is sufficient. He based this on a flawed use of statistics. For his comparison (to a range of 100 miles) he used the mean journey distance of 10 miles whereas the correct comparison is against the median.

I have no idea what the median is but, as I showed, it has to be quite a bit greater than 10 miles.
OK, but if you have no idea what it is it's a bit pointless you trying to pontificate about the problems associated with it.
 
t it is it's a bit pointless you trying to pontificate about the problems associated with it.

No pontificating, I'll leave that to you. And it was far from pointless, as pointing out that the comparison was wrong shows that any conclusion based on it was of no use.

And do I take it that you now accept that what you wrote was irrelevant?
 
So - what is the plan for when they stop making IC cars?
That's beyond the next election, so politicians don't seem to be bothered about making one :whistle: But more seriously the stated policy is (IMO) a load of hype and sooner or later it will be quietly forgotten about - when people start to point out the real and insurmountable (or at least, exceedingly eye wateringly expensive to deal with) problems - not least, where all this lecky will come from when it's "the wrong kind of wind" for the magic windmills. EVs will gain ground, but as the old saying goes, reports of the death of the IC engine are grossly exaggerated.

And while I'm sure there's been research into electric trucks - it would be interesting to see the battery requirements for a viable "all day" vehicle. Of course, while many trucks could be charged overnight (or during the day for "night shift" types of use), there are many that are away from base for days on end with the drivers sleeping in the cabs.
Time's money, and I can't see a haulier allowing trucks to be taking downtimes measured in hours to recharge during a shift. Similarly, I can't see it being practical to mass-provide the sort of charging infrastructure that would be needed for mass adoption - just the re-arrangement of lorry parking areas to make room for the chargers would reduce parking capacity significantly.

Perhaps someday the politicos will take off the rose tinted glasses and realise that EVs aren't the solution to everything. For one thing, developments have been going on for a while on things like synthesising methanol from water, atmospheric CO2, and energy - but of course it's not as sexy as "electric" or "hydrogen" (or perhaps those behind it aren't as good at lobbying) and they've not had the same sort of support. Methanol would be a generally good energy storage medium - easily handled (liquid without special handling so can use existing infrastructure, miscible with petrol and ethanol in any proportion, and if done at the design stage would need next to no cost in vehicle adaptations to run on it. Presumably it's because of all these advantages that TPTB aren't interested :whistle:

At the very least, hybrids of one form or another would be a good intermediate stage. Though many hybrids get a lot of the gains through better matching of engine and road speeds - and that can be done with things like Torotrak, though it looks sadly like things haven't gone too well for them lately : https://www.ft.com/content/456cc28e-e976-11e6-967b-c88452263daf
Don't forget that Toyota's hybrid system has two big motor/generators connected to an epicyclic gearbox to give a variable ratio drive as well as the electric drive - during use, a significant proportion of engine power is converted to electricity and back again with the losses that incurs.

1l of petrol is 9.5kWh, 1l of diesel is 9.9 (https://en.wikipedia.org/wiki/Energy_density#Energy_density_in_energy_storage_and_in_fuel).

If we use the less onerous petrol figure, and assume that a pump transfers 1l/s, , that makes each pump a 9.5kWh/s, i.e. 34.2MW appliance. If you want to use a 30% efficiency factor, then it's a 10.26MW one.
I recalled that the effective transfer rate is exceedingly high, but CBA to find the figures - thanks for doing that. It does show just why we use these very energy dense liquid fuels for mobile applications ;)
That would be the required charge rate for a "petrol pump equivalent", but using the "charge while you shop" model then it wouldn't be needed. Taking our own car, we might put 50l in when we fill it, but at a charge point we could do that over (say) an hour - so under 1l/min but would still require the equivalent of a 1/2MW charger.
But, it makes little practical difference in terms of supply capacity since it would just be the difference between a small number of very high power chargers (equivalent to the current forecourt arrangement of getting cars through as fast as possible) and a large number of higher power chargers taking the same overall power from the supply.
 
And do I take it that you now accept that what you wrote was irrelevant?
No, because it is not.

And no matter how much you go on about it it will never be irrelevant to consider usage patterns of facilities when planning their provision.
 
And while I'm sure there's been research into electric trucks - it would be interesting to see the battery requirements for a viable "all day" vehicle.
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