Green Building Forum - An Engineer speaks!

An Engineer speaks!

fostertom — Sat, 03 Jun 2023 10:22:55 +0100

https://www.theguardian.com/commentisfree/2023/jun/03/electric-vehicles-early-adopter-petrol-car-ev-environment-rowan-atkinson

An Engineer speaks!

djh — Sat, 03 Jun 2023 11:11:46 +0100

https://rmi.org/we-need-hydrogen-but-not-for-everything/

An Engineer speaks!

WillInAberdeen — Sat, 03 Jun 2023 11:32:12 +0100

Total baloney - worthy of Mr Bean or Johnny English! He implies that an electric car is made, used for three years and then thrown away like "fast fashion" so the manufacturing emissions are not paid back, whereas a diesel car will be kept running for thirty years.

Very many real engineers have looked very carefully at this and found that electric cars payback their manufacturing emissions within the first year or two and are a net benefit from then on. And many electric or hybrid Leafs and Priuses are ten or fifteen years old and still going well.

The stuff about hydrogen and hydrogen-derived e-fuel is also baloney. Hydrogen has been abandoned by all the major manufacturers, because it is inherently many times more expensive than the electricity it is made from, and e-fuels are inherently even pricier so only for Porsches and Ferraris. The UK hydrogen fuel stations are quietly being closed down.

While we are at it, he is not an engineer. An engineer is like a doctor or an architect, with a degree, 5-7 years work experience, more exams, accredited by a regulatory body, regular CPD, gets struck off if accountable for a mistake. In most countries it is illegal to claim you are an engineer or doctor without doing this.

Television comics are not engineers/doctors/architects. Neither are the 'engineers' who fix boilers and washing machines!

An Engineer speaks!

WillInAberdeen — Sat, 03 Jun 2023 11:44:54 +0100

"the number of hydrogen refuelling stations in the UK has dwindled from 15 in 2021 to just five remaining" [two of them are here in Aberdeen!]

https://innovationorigins.com/en/first-shell-now-motive-hydrogen-fuel-station-closures-continue-in-the-uk/

An Engineer speaks!

fostertom — Sat, 03 Jun 2023 11:48:03 +0100

Desired result from our principal founts of knowledge! Thanks. Has-Bean.

An Engineer speaks!

WillInAberdeen — Sat, 03 Jun 2023 12:56:42 +0100

Think he needs Baldrick to supply him with a more cunning plan than this one!

An Engineer speaks!

marktime — Sat, 03 Jun 2023 14:30:13 +0100

Quote; "While we are at it, he is not an engineer. An engineer is like a doctor or an architect, with a degree, 5-7 years work experience, more exams, accredited by a regulatory body, regular CPD, gets struck off if accountable for a mistake. In most countries it is illegal to claim you are an engineer or doctor without doing this.

Television comics are not engineers/doctors/architects. Neither are the 'engineers' who fix boilers and washing machines!"

You obviously don't know much about engineers so the rest of your comments belong in the bin where they deserve to be.

An Engineer speaks!

WillInAberdeen — Sat, 03 Jun 2023 15:00:20 +0100

Think I know a bit about engineers, I've trained quite a lot of them.

An Engineer speaks!

djh — Sat, 03 Jun 2023 15:14:14 +0100

Ooh, I'll get the popcorn

(edit: crossed with Will's reply)

An Engineer speaks!

fostertom — Sat, 03 Jun 2023 17:19:57 +0100

Intriguing - what's this that some of us 'know' about Engineers?

An Engineer speaks!

marktime — Thu, 08 Jun 2023 09:18:52 +0100

https://www.theguardian.com/environment/2023/jun/08/fact-check-why-rowan-atkinson-is-wrong-about-electric-vehicles

An elegant rebuttal. Play's the ball, not the man.

An Engineer speaks!

fostertom — Thu, 08 Jun 2023 09:58:27 +0100

Excellent. Interesting how national-treasure commedians so often show their true, reactionary colours, with advancing years - John Cleese, even Russell Brand, sooner than timetabled

An Engineer speaks!

LF — Thu, 08 Jun 2023 15:17:37 +0100

"I is an Engineer"

It is a shame most of the world seem not to care about CO2. My children are ... well what difference can I make !!

I did some calcs on running my diesel work vehicle.(14 yr old, well maintained)
I cannot see a way of running electric as for distances and response time I need (I carry ~500kg of equipment too). I am not near cities.

For 15 k miles it is about 4.3 te/CO2 so about the same as a family of 4 flying to Teneriffe.
Of this 0.4 te is assumed from the building of the car.

Electric vehicle at 9 year life would be about ~38% of 14 year old diesel CO2.
I cannot see a 4 year life being credible but the numbers were done.

Hopefully the grid supply gets bogger and CO2 level keeps falling. I doubt it can run all the heat pumps and cars when it is -10 C for 10 days or whatever we had last winter.

My ball park numbers. I got 6 te to build a diesel and 9 te for a electric car from somewhere.

Diesel - 15k miles a year at 47 ish mpg. 3.8 te from fuel, 0.4 te from build (14 yr old) Overall 4.2 te/year CO2
Electric Car same miles 4 miles/kwh, 0.193 kgCO2/kwh from grid, 4 yr life => 2.25 te/yr overall 3.0 te/year
Electric Car same miles 4 miles/kwh, 0.193 kgCO2/kwh from grid, 9 yr life => 0.9 te/yr overall 1.6 te/year
I return flight to Teneriffe for family of 4 => 4.1 te CO2

An Engineer speaks!

neelpeel — Thu, 08 Jun 2023 16:56:09 +0100

So LF you assume 14+ years for a diesel but only 4-9 years for an electric?

The EV motors run forever and the batteries degrade at <2% per year if used sensibly. So a newish EV with a 250 mile range will still have 200+ mile range after 10 years. So, I would assume 15+ useable years on a recent EV.

In my experience old diesels can keep going for huge mileage, but they are like Trigger's broom...3 new exhausts. new clutch. new turbo, gearbox, pipes, fan belts, fuel injectors, glow plugs, etc. That's before you start on the regular maintenance stuff like engine oil, fuel filters, brakes (EVs brake much less due to KERS).
I'd like to see a lifetime calculation with sensible assumptions built in.
You can also go one step further and charge your EV with PV, which would also sway the calcs.
The EV battery may well have a life after the car is long gone, which would also sway the calcs.

That said, at 500kg payload you may be struggling as there aren't many decent EV vans yet.

An Engineer speaks!

fostertom — Thu, 08 Jun 2023 18:05:20 +0100

Posted By: neelpeelTrigger's broom

Haven't heard the concept called that before - perfect!

An Engineer speaks!

Peter_in_Hungary — Thu, 08 Jun 2023 19:35:14 +0100

Posted By: fostertom
Posted By: neelpeelTrigger's broom
Haven't heard the concept called that before - perfect!

The way I know the story is -

I've been using the same broom for 40 years and it's still good - it's had 7 new heads and 5 new handles.

An Engineer speaks!

LF — Thu, 08 Jun 2023 21:14:55 +0100

Thanks for comments . Logical. My current 520 auto diesel is 260k miles and has not had much done. A turbo a 160k and everything else routine servicing.
If all solar/wind then build around 0.9 te/year. So 1/4 if it lasts 9 years.

An Engineer speaks!

LF — Fri, 09 Jun 2023 09:43:45 +0100

Attached workings, I tried to attach xls and ods but not allowed.

It is ball park

If I buy new/newer then 6 te of carbon for a new car in the world (1.5 family trips to Teneriffe)
My strategy is to run this car till it becomes unreliable or fails completely.

I have a replacement in stock that is same model and age but much less wear.(I understand this has used carbon)

An Engineer speaks!

fostertom — Fri, 09 Jun 2023 09:45:13 +0100

Posted By: Peter_in_HungaryThe way I know the story is -

I've been using the same broom for 40 years and it's still good - it's had 7 new heads and 5 new handles.

Me too, except that it's a 100yr old woodsman's axe. But why Trigger? (actually I read that as Tigger, which is what I thought brilliant, in some way that would soon be wonderfully explained to me!)

An Engineer speaks!

owlman — Fri, 09 Jun 2023 10:22:10 +0100

Only Fools and Horses, Tom

https://www.bing.com/videos/search?q=triggers+broom+youtube&view=detail&mid=887FC8FB8E5947BC1A43887FC8FB8E5947BC1A43&FORM=VIRE0&ru=%2fsearch%3fq%3dtriggers%2bbroom%2byoutube%26form%3dANNTH1%26ref

An Engineer speaks!

neelpeel — Fri, 09 Jun 2023 12:07:57 +0100

Posted By: owlmanOnly Fools and Horses, Tom

https://www.bing.com/videos/search?q=triggers+broom+youtube&view=detail&mid=887FC8FB8E5947BC1A43887FC8FB8E5947BC1A43&FORM=VIRE0&ru=%2fsearch%3fq%3dtriggers%2bbroom%2byoutube%26form%3dANNTH1%26ref" rel="nofollow" >https://www.bing.com/videos/search?q=triggers+broom+youtube&view=detail&mid=887FC8FB8E5947BC1A43887FC8FB8E5947BC1A43&FORM=VIRE0&ru=%2fsearch%3fq%3dtriggers%2bbroom%2byoutube%26form%3dANNTH1%26ref

That's the one!

An Engineer speaks!

neelpeel — Fri, 09 Jun 2023 12:39:48 +0100

Posted By: LFAttached workings, I tried to attach xls and ods but not allowed.

It is ball park

If I buy new/newer then 6 te of carbon for a new car in the world (1.5 family trips to Teneriffe)
My strategy is to run this car till it becomes unreliable or fails completely.

I have a replacement in stock that is same model and age but much less wear.(I understand this has used carbon)
http://www.greenbuildingforum.co.uk/newforum/?PostBackAction=Download&AttachmentID=8568" >diesel electric calcs.pdf

I still think it is unfair to assume 14 yrs for a diesel and 4 or 10 years for electric. I think with the new crop of EVs they will on average outlast the diesel equivalent.
You mention more tyre wear - I haven't noticed this, but I accept in theory they are slightly heavier so possibly. But you don't mention less brake wear, and all the other points I mention regarding wear and tear.
No sensible person would dispute that there is a CO2 content for the electricity, but thankfully this is reducing year on year and an estimate should possibly be made for the 10-15 year lifecycle.
Solar radically changes this, but it all depends if you are able to install.

However, if I was regularly doing 500 mile trips I would stick with a diesel for now due to crappy charging infrastructure.

An Engineer speaks!

WillInAberdeen — Fri, 09 Jun 2023 12:59:55 +0100

Hi LF, nice to see workings! thanks for sharing.

The co2 for manufacturing the existing diesel is a 'sunk cost', it won't go away, irrespective whether it is scrapped or driven some more.

The CO2 for manufacturing the next vehicle is an optional cost, you can choose whether to buy it now or later or never.

Question is : does bringing forward the manufacturing of the next vehicle, save CO2 overall?

Option 1 : keep the diesel going for another 3 years : fuel emissions 3x 3.8t = 11.4t

Option 2: scrap the diesel now, manufacture new EV, drive it 3 years: additional manufacturing emissions 9t, fuel emissions 3x0.7t, total 11.1t

So for your usage it is (only just) worthwhile for emissions to scrap the diesel now (despite its sunk costs) and go electric. On top of that you'd have a 3-year old EV with years of life left.

The financial calcs might look completely different! And the practical side for your needs.

The 'paradox of inaction' is we get the opposite answer if looking ahead only 1yr instead of 3yr. So it seems good to keep the diesel going for just one more year, and then think the same again then, and again after another year, and so on, so nothing changes. That's how my car got so old!

Another paradox is it is actually better to scrap nearly-new diesel cars (thus preventing a long lifetime of emissions) and keep late-life bangers on the road (they'll scrap themselves before very long!).

(ETA: taken as read that the replacement vehicle would be electric - the previous calcs showed very clearly that manufacturing a new diesel vehicle to replace a scrapped diesel would mean much higher emissions)

An Engineer speaks!

djh — Sat, 10 Jun 2023 10:38:15 +0100

Posted By: WillInAberdeenThe 'paradox of inaction' is we get the opposite answer if looking ahead only 1yr instead of 3yr. So it seems good to keep the diesel going for just one more year, and then think the same again then, and again after another year, and so on, so nothing changes. That's how my car got so old!

Is there an 'approved', 'logical' method to determine an appropriate period for comparison in making decisions like this?

Another paradox is it is actually better to scrap nearly-new diesel cars (thus preventing a long lifetime of emissions) and keep late-life bangers on the road (they'll scrap themselves before very long!).

I'm not convinced of that one, given that diesel emissions standards have slowly been tightened over the years.

An Engineer speaks!

revor — Sun, 11 Jun 2023 06:50:21 +0100

Posted By: LFDiesel - 15k miles a year at 47 ish mpg. 3.8 te from fuel, 0.4 te from build (14 yr old) Overall 4.2 te/year CO2
Electric Car same miles 4 miles/kwh, 0.193 kgCO2/kwh from grid, 4 yr life => 2.25 te/yr overall 3.0 te/year
Electric Car same miles 4 miles/kwh, 0.193 kgCO2/kwh from grid, 9 yr life => 0.9 te/yr overall 1.6 te/year
I return flight to Teneriffe for family of 4 => 4.1 te CO2

Where do these CO2 figures come from?. I would like to do our carbon footprint calculation which I believe is v low compared to UK average whatever that may be.

An Engineer speaks!

WillInAberdeen — Sun, 11 Jun 2023 12:02:22 +0100

>>> "Is there an 'approved', 'logical' method to determine an appropriate period for comparison in making decisions like this?"

An economist would compare over the whole lifecycle of the function or service (eg if the owner needs business transport in several vehicles for the next 10 years, that's how long). Then discount it to a Net Present Value, as costs and benefits in the far future are less tangible than today, though debatable how this applies to CO2. Then compare the opportunity cost/benefit of tying up resources in cars which could be used elsewhere (on PV like neel suggested?). Then do some risks and uncertainties analysis.

But that's very boring, car ownership is more emotional and less 'logical'! So there is market for Audis as well as Skodas.. same with houses. I'm not an economist!

>>>> "I'm not convinced of that one, given that diesel emissions standards have slowly been tightened over the years."

My bad, should have said specifically CO2 emissions. Nobody is actually suggesting that newish diesel cars are going to be scrapped to replace with EVs, that was the straw man in the original article.

An Engineer speaks!

djh — Sun, 11 Jun 2023 17:25:13 +0100

Posted By: WillInAberdeen>>> "Is there an 'approved', 'logical' method to determine an appropriate period for comparison in making decisions like this?"

An economist would compare over the whole lifecycle of the function or service

Yes, I don't understand why it would be more reasonable to compare for 3 years rather than 1 or even 10?

An Engineer speaks!

neelpeel — Mon, 12 Jun 2023 08:27:20 +0100

Posted By: revor
Posted By: LFDiesel - 15k miles a year at 47 ish mpg. 3.8 te from fuel, 0.4 te from build (14 yr old) Overall 4.2 te/year CO2
Electric Car same miles 4 miles/kwh, 0.193 kgCO2/kwh from grid, 4 yr life => 2.25 te/yr overall 3.0 te/year
Electric Car same miles 4 miles/kwh, 0.193 kgCO2/kwh from grid, 9 yr life => 0.9 te/yr overall 1.6 te/year
I return flight to Teneriffe for family of 4 => 4.1 te CO2

Where do these CO2 figures come from?. I would like to do our carbon footprint calculation which I believe is v low compared to UK average whatever that may be.

I've used this site before...
https://www.carbonfootprint.com/calculator.aspx

An Engineer speaks!

bhommels — Mon, 12 Jun 2023 09:13:02 +0100

Thanks. Playing with these kinds of calculators always raises lots of questions
It looks like my footprint is completely dominated by secondary emissions which is also the hardest to estimate, and control. For example: I clearly should stop paying off my mortgage as it adds as much to my footprint as heating the house!
Is this also the experience of others?
I am not sure how it accounts for CO2 spent for the 'greater good', like national infrastructure and defence. Also, there is no entry for ferries which I use a few times a year.

An Engineer speaks!

revor — Tue, 13 Jun 2023 12:33:37 +0100

Posted By: neelpeelI've used this site before...
https://www.carbonfootprint.com/calculator.aspx

Had a go surprised I was just above uk average until I realised I had done it as per household rather than person. Good chunk was food we eat can't seeing us giving up on that we already make eco choices and grow a lot which we sell at the gate.