BEVs

Use this board for general non-cycling-related chat, or to introduce yourself to the forum.

I appreciate the BEV mostly because they...

cost less to run than an equivalent petrol or diesel car
9
12%
are reducing the harm done to our planet and its lifeforms
10
14%
are quiet and smooth
7
10%
can be refuelled with my own renewable energy production
10
14%
can supply energy to the home and Grid
4
5%
No! I am concerned they are just another way of making the car seem acceptable
33
45%
 
Total votes: 73

Nearholmer
Posts: 3898
Joined: 26 Mar 2022, 7:13am

Re: BEVs

Post by Nearholmer »

Nuclear is a real conundrum IMO.

Without changes to lifestyle of a kind and at a pace that I doubt could find political consensus in the real world, it seems essential as part of a CO2 reduction programme, but I share the reservations about storing-up problems in the long term, and about low-probability, high-consequence accidents.

Anyway, if newspaper guesswork is to be believed, HMG looks set to make a bonfire of net-zero targets, so we don’t have to worry, do we?
Biospace
Posts: 1990
Joined: 24 Jun 2019, 12:23pm

Re: BEVs

Post by Biospace »

Carlton green wrote: 26 Mar 2023, 2:12pm
[XAP]Bob wrote: 26 Mar 2023, 11:16am
Nearholmer wrote: 25 Mar 2023, 8:06pm I get the academic’s point: by adding car charging, a new load, to our night-time load, we (for the most part) add gas to the generation mix, so we really ought to count cars as charged not by “average grid mix”, but by “nearly all gas”, which hugely increases their carbon footprint. The marginal impact of this particular marginal addition is clear.
I disagree with the assessment - although even if all the electricity came from burning gas they would still be significantly lower carbon than an ICE, and the very significant reduction in emissions in populated areas is unaffected.
Why do you disagree with the assessment? It seems a perfectly logical argument to me but if it really is flawed then put your own data and counter argument forward.

I thought the point about carbon from electricity generated for EV use and carbon produced by fossil fuels in ICV use interesting but I’d like to see data on that please - or a pointer to a post where it has already been supplied.

The significant reduction in harmful emissions in populated areas likely has some merit - particularly so in heavily built-up areas - and meaningful reductions are good.

Yes, in congested traffic all electric vehicles are super-efficient compared with a ICEv, they also produce no excess pollution when starting 'from cold' - a ICEv starting on a morning and heading directly into a traffic jam is least good for local air quality, especially larger engines. Once up to temperature, modern vehicle exhausts are remarkably clean, scientists suggest that now it is tyre particulates which pose more of a threat to our health but there's as much looking the other way with this as there was with emissions in the 80s.

On a cold day on the open road, a BEV holds least advantage over the ICEv, even if you have lights, wipers, demisters and heating switched off. As batteries age they lose capacity and I'm told a battery which has only 70% capacity could well require as much or more energy to fully charge it as one with 100% capacity. Moreover, it will be less efficient in operation, also. However, they are improving all the time and vehicle batteries are proving better than most expected in real world use.

This post on page 6 of this thread viewtopic.php?p=1760627#p1760627 compares electric Golfs with petrol and diesel ones over 200,000km in the UK with UK grid electricity. I agreed with Nearholmer that the cradle to grave vehicle carbon calculator used for this (which jdsk had found was the best) does seem to give results less favourable than others for BEVs, but it is exceedingly thorough in its analysis. These are its sources for non-US figures.


https://www.sciencedirect.com/science/a ... via%3Dihub
https://www.eea.europa.eu/data-and-maps ... -2016-prov
https://theicct.org/real-world-vehicle- ... time-high/
https://www.ivl.se/download/18.59222817 ... ies%20.pdf
https://www.sciencedirect.com/science/a ... 5119302715
https://onlinelibrary.wiley.com/doi/abs ... jiec.12072
https://iopscience.iop.org/article/10.1 ... 1/5/054010
https://www.sciencedirect.com/science/a ... via%3Dihub
Jdsk
Posts: 24478
Joined: 5 Mar 2019, 5:42pm

Re: BEVs

Post by Jdsk »

Biospace wrote: 26 Mar 2023, 3:35pm ...
As batteries age they lose capacity and I'm told a battery which has only 70% capacity could well require as much or more energy to fully charge it as one with 100% capacity. Moreover, it will be less efficient in operation, also. However, they are improving all the time.
...
What's the source of the view that degradation to 70% will occur in production BEVs?

Thanks

Jonathan
User avatar
[XAP]Bob
Posts: 19793
Joined: 26 Sep 2008, 4:12pm

Re: BEVs

Post by [XAP]Bob »

Nearholmer wrote: 26 Mar 2023, 11:33am
I disagree with the assessment
Why, or how?
I don't allocate all EVs to marginal generation any more than I do all lighting, cooking, heating, or anything else - because literally everything that gets turned on is "marginal load" - even my home server, which runs 24/7 is "marginal load" in that were I to turn it off the energy that wouldn't need to be produced would be the most polluting.
That allocation fails even harder with loads which are generally scheduled to be used at times of minimal load on the grid.

That doesn't mean I don't see the argument, but I feel it would have to be applied equally to every kWh I choose to use - and that is then obviously wrong.

Over the next few months I expect that alot of the electrons in the EV will be direct from my own solar, but following the above logic I could have exported that and "saved" the emissions from a gas plant - and that is clearly not a sane allocation.

It doesn't really matter anyway...

A gallon of petrol releases ~11kg CO2 (click) leading to ~170g/km in the UK(click)

A gas plant is somewhere around 400g/kWh (click) that kWh will get you 6km pretty easily, which ends up as ~67g/km

The balance is still very strongly in the BEV's favour.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.
Jdsk
Posts: 24478
Joined: 5 Mar 2019, 5:42pm

Re: BEVs

Post by Jdsk »

Nearholmer wrote: 26 Mar 2023, 3:23pm Nuclear is a real conundrum IMO.

Without changes to lifestyle of a kind and at a pace that I doubt could find political consensus in the real world, it seems essential as part of a CO2 reduction programme, but I share the reservations about storing-up problems in the long term, and about low-probability, high-consequence accidents.
...
Yes, that's the part of the approach that I find by far the most difficult on which to come to a view. In one sense it gets more attractive because we have failed to implement the other parts quickly enough. But then traditional fission power stations take a long time to go live.

Jonathan
Biospace
Posts: 1990
Joined: 24 Jun 2019, 12:23pm

Re: BEVs

Post by Biospace »

Jdsk wrote: 26 Mar 2023, 3:39pm What's the source of the view that degradation to 70% will occur in production BEVs?
The point being made was that as a battery loses xWh capacity, it doesn't take 1-xWh less energy to recharge fully. I used a 'real' number rather than 'x' - no offence intended with use of the number 70 or 0.7, I've no idea how many batteries in the world's BEVs are currently at that level!
Last edited by Biospace on 26 Mar 2023, 3:46pm, edited 2 times in total.
Nearholmer
Posts: 3898
Joined: 26 Mar 2022, 7:13am

Re: BEVs

Post by Nearholmer »

It might be a case of “70% of what?”.

An EV battery, pretty much any well-specced secondary battery come to that, will deliver considerably more than required performance when new, degrading to something less than required performance over time and charge-discharge cycles. So which figure is deemed to be 100%? Is it the required performance, or the as-new performance? And, how much time and how many discharge-discharge cycles does whatever the decay is occur over?
Jdsk
Posts: 24478
Joined: 5 Mar 2019, 5:42pm

Re: BEVs

Post by Jdsk »

Biospace wrote: 26 Mar 2023, 3:44pm
Jdsk wrote: 26 Mar 2023, 3:39pm What's the source of the view that degradation to 70% will occur in production BEVs?
The point being made was that as a battery loses xWh capacity, it doesn't take 1-xWh less energy to recharge fully. I used a 'real' number rather than 'x' - no offence intended with use of the number 70 or 0.7, I've no idea how many batteries in the world's BEVs are currently at that level!
Thanks.

I'm not expecting anything like that in the first 10 years.

Jonathan

Edited: Crossed with Nearholmer's.
Biospace
Posts: 1990
Joined: 24 Jun 2019, 12:23pm

Re: BEVs

Post by Biospace »

Jdsk wrote: 26 Mar 2023, 3:46pm
Biospace wrote: 26 Mar 2023, 3:44pm
Jdsk wrote: 26 Mar 2023, 3:39pm What's the source of the view that degradation to 70% will occur in production BEVs?
The point being made was that as a battery loses xWh capacity, it doesn't take 1-xWh less energy to recharge fully. I used a 'real' number rather than 'x' - no offence intended with use of the number 70 or 0.7, I've no idea how many batteries in the world's BEVs are currently at that level!
Thanks.

I'm not expecting anything like that in the first 10 years.

Jonathan

Edited: Crossed with Nearholmer's.
No, my apologies - I hadn't intended worrying any BEV owners, as I mentioned EV batteries are performing better than many expected.

I was pointing to the use of taxi companies using Leafs several years ago as proof that 200,000 miles could be taken as a rough estimate of their life expectancy, I suspect many will last well beyond in reasonable condition.

One of their largest single positives is the lack of required maintenance to the drivetrain, which carried out in less than perfect fashion invariably reduces the life of a vehicle (one reason spark plug life has been extended so enormously), but of course if neglected can end the life of a vehicle.
Nearholmer
Posts: 3898
Joined: 26 Mar 2022, 7:13am

Re: BEVs

Post by Nearholmer »

I don't allocate all EVs to marginal generation
Marginal effects are about change, in this case changing from barely any EVs to charge to many to charge, so it seems perfectly fair to view it the way the academic did.

The marginal affect (effect?? I always get that wrong!) of swooping from filament to LED lighting might be looked at the same way. It was a fairly quick and near-universal change, which must have improved our grid-mix disproportionately.
The balance is still very strongly in the BEV's favour.
Yes, but ….. the but being the difference in CO2 emitted during construction, which eats into that difference between the two. The EV still does better, but not by such a large margin.

(As a BTW, I calculated the respective figures for myself from reputable underlying numbers, and got 167g/km vs 77g/km, so very close to what you cite.)
Biospace
Posts: 1990
Joined: 24 Jun 2019, 12:23pm

Re: BEVs

Post by Biospace »

Nuclear is a real conundrum IMO.

Without changes to lifestyle of a kind and at a pace that I doubt could find political consensus in the real world, it seems essential as part of a CO2 reduction programme, but I share the reservations about storing-up problems in the long term, and about low-probability, high-consequence accidents.
Totally.

Freely available and cheap energy is well-documented to advance societies, but I would suggest there is a point beyond which, after sustained, limitless and cheap energy, lazy thinking and behaviour can become a problem. Indeed, that a period of reduction in available energy might even advance progress.
User avatar
[XAP]Bob
Posts: 19793
Joined: 26 Sep 2008, 4:12pm

Re: BEVs

Post by [XAP]Bob »

Nearholmer wrote: 26 Mar 2023, 4:22pm
I don't allocate all EVs to marginal generation
Marginal effects are about change, in this case changing from barely any EVs to charge to many to charge, so it seems perfectly fair to view it the way the academic did.

The marginal affect (effect?? I always get that wrong!) of swooping from filament to LED lighting might be looked at the same way. It was a fairly quick and near-universal change, which must have improved our grid-mix disproportionately.
The balance is still very strongly in the BEV's favour.
Yes, but ….. the but being the difference in CO2 emitted during construction, which eats into that difference between the two. The EV still does better, but not by such a large margin.

(As a BTW, I calculated the respective figures for myself from reputable underlying numbers, and got 167g/km vs 77g/km, so very close to what you cite.)
If I recall correctly gas is about double the Uk grid intensity… so the delta drops from ~135 to ~100 - maintaining 75% of the benefit even when doubling the allocated intensity.
Doubling a small number that number remains small - we do need some better “intensity aware” tariffs to further promote better usage - and better still some biderectional CCS please!

I’m yet to be convinced that allocating all to marginal generation is fair at all at the moment, and we certyhave the ability to make it not true as we roll out larger numbers.

Mixergy, for instance, do intelligent heating (and pausing) to optimise green use
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.
Carlton green
Posts: 3626
Joined: 22 Jun 2019, 12:27pm

Re: BEVs

Post by Carlton green »

Jdsk wrote: 26 Mar 2023, 3:46pm
Biospace wrote: 26 Mar 2023, 3:44pm
Jdsk wrote: 26 Mar 2023, 3:39pm What's the source of the view that degradation to 70% will occur in production BEVs?
The point being made was that as a battery loses xWh capacity, it doesn't take 1-xWh less energy to recharge fully. I used a 'real' number rather than 'x' - no offence intended with use of the number 70 or 0.7, I've no idea how many batteries in the world's BEVs are currently at that level!
Thanks.

I'm not expecting anything like that in the first 10 years.

Jonathan

Edited: Crossed with Nearholmer's.
I can’t give the source now but IIIRC, from a few days ago, a 10% degradation every five years was how I read the displayed graph, so circa 80% capacity at ten years old. I don’t find that encouraging but, there’s worse to come, in addition the manufacturers’ actually expect much reduced capacity, apparently just 75% at eight years is considered to be OK :shock: . Talk about a naff guarantee, they’ll restore to just 75% capacity … I honestly wonder why any sane person would accept such poor durability.
1.
BATTERY QUALITY GUARANTEE
i. 24 KWH LEAF : If the battery capacity level gauge of your 24 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 60,000 miles or the first 5 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
ii. 30 KWH LEAF : If the battery capacity level gauge of your 30 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 100,000 miles or the first 8 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
iii. 40 KWH LEAF : If the battery capacity level gauge of your 40 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 100,000 miles or the first 8 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
Source: https://www.nissan.co.uk/content/dam/Ni ... .02.18.pdf

Edit.

And from Volkswagen, and again pretty poor IMHO:
We guarantee a minimum capacity of 70 percent for eight years or 160,000 kilometers.
Source: https://www.volkswagenag.com/en/news/st ... a-car.html
Last edited by Carlton green on 26 Mar 2023, 7:36pm, edited 2 times in total.
Don’t fret, it’s OK to: ride a simple old bike; ride slowly, walk, rest and admire the view; ride off-road; ride in your raincoat; ride by yourself; ride in the dark; and ride one hundred yards or one hundred miles. Your bike and your choices to suit you.
Nearholmer
Posts: 3898
Joined: 26 Mar 2022, 7:13am

Re: BEVs

Post by Nearholmer »

% of what, though? Initial capacity, or warranted capacity upon which vehicle capability is calculated?

A battery like this is an unusual thing: you buy more than you need, knowing it will “wear out”, like set of tyres - it’s a bit like a guarantee that your tyres will retain x tread depth after y miles.

So far though, experience seems to be that the west-out rate is lower than anticipated.

The other thing is that a market for “tired” e-cars seems to be emerging, old-electric-bangers, for people who only need a few tens of miles range.
Last edited by Nearholmer on 26 Mar 2023, 7:23pm, edited 3 times in total.
Jdsk
Posts: 24478
Joined: 5 Mar 2019, 5:42pm

Re: BEVs

Post by Jdsk »

Carlton green wrote: 26 Mar 2023, 6:54pm
Jdsk wrote: 26 Mar 2023, 3:46pm
Biospace wrote: 26 Mar 2023, 3:44pm The point being made was that as a battery loses xWh capacity, it doesn't take 1-xWh less energy to recharge fully. I used a 'real' number rather than 'x' - no offence intended with use of the number 70 or 0.7, I've no idea how many batteries in the world's BEVs are currently at that level!
I'm not expecting anything like that in the first 10 years.
I can’t give the source now but IIIRC, from a few days ago, a 10% degradation every five years was how I read the displayed graph, so circa 80% capacity at ten years old. I don’t find that encouraging but, there’s worse to come, in addition the manufacturers’ actually expect much reduced capacity, apparently just 75% at eight years is OK :shock: . Talk about a naff guarantee, they’ll restore to just 75% capacity … I honestly wonder why any sane person would accept such poor durability.
1.
BATTERY QUALITY GUARANTEE
i. 24 KWH LEAF : If the battery capacity level gauge of your 24 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 60,000 miles or the first 5 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
ii. 30 KWH LEAF : If the battery capacity level gauge of your 30 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 100,000 miles or the first 8 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
iii. 40 KWH LEAF : If the battery capacity level gauge of your 40 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 100,000 miles or the first 8 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
Source: https://www.nissan.co.uk/content/dam/Ni ... .02.18.pdf
I'd be interested if you could find the source showing 10% every 5 years.

Manufacturers’ guarantees are about replacing things that they don't expect will need replacing.

Jonathan
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