At Last . . . .Some Hydrogen Sense

[RobH]

I think that was a truck carrying gas cylinders John (hence the repeated explosions) -  I remember first seeing the video about six or seven years ago.  Towards the end you can see a cylinder jetting off into the trees like a rocket. 

 

 

Edited July 28, 2023 by RobH

[boxofbits]

1 hour ago, Bleednipple said:

Thanks. I agree there are lots of very different figures/analyses out there to choose from. I had seen this one, done by McKinsey this year:  

https://www.visualcapitalist.com/life-cycle-emissions-evs-vs-combustion-engine-vehicles/ 

It estimates lifetime emissions of 39 tonnes for BEVs versus 55 tonnes for ICE. So not actually all that different, proportionately from what the Inset article says. BUT that's based on global average grid carbon intensity; given that the UK's is only 60% of that average level would reduce the UK BEV lifetime figure to perhaps 29 tonnes which is a little over half that of ICE. And that divergence will increase with the continued growth of renewables in the generation mix.

Nigel

 

 

 

I’m sure over time Nigel, increases in the UK’s ability to produce greener electricity will have a downward effect on emissions.

One thing I would say is I’ve noticed that imports of electricity into the UK have risen by something like 44% in recent years and could, and I say that with caution, help skew those figures? Just a thought….as we don’t necessarily know how imported electricity has been generated. Does that mean it’s CO footprint is lost to a bit of carbon trading possibly!

On the Coryton fuel figures I mentioned and as quoted by the manufacturer, a 65% reduction in CO emissions for ICE’s using your figure of 55 tonnes, would reduce it to just under 20 tonnes. One thing is certain though, that both plant based fuels and clean electricity appear to be driving things in the right direction, so why not have the choice of either?

Kevin

[john.r.davies]

23 hours ago, RobH said:

But had the electric car taken off at the time, instead of ICE, the exact same curve would probably have resulted. 

Indeed Rob!  You might like to read this extraordinary story, of how a pair of  swindlers, riding on the initial revulsion of Londoners at the  noise and fumes from ICE buses, creamed the modern equivalent of £10 million from investors on the promise of hundreds of "Electrobuses" on London's streets -  and kept the money.  See: How crooks stalled the rise of electric cars for 100 years | New Scientist

John

[Bleednipple]

1 hour ago, boxofbits said:

On the Coryton fuel figures I mentioned and as quoted by the manufacturer, a 65% reduction in CO emissions for ICE’s using your figure of 55 tonnes, would reduce it to just under 20 tonnes. One thing is certain though, that both plant based fuels and clean electricity appear to be driving things in the right direction, so why not have the choice of either?

Both 'sustainable' biofuels (like the Coryton example) and synthetic fuels ('e-fuels') will have their place for niche applications in transportation, including maybe powering our historic cars and also to some extent for trucks and - possibly - some aviation applications.

But the problem in both biofuels and synthetic is scale. Liquid biofuels made from organic waste are limited by the supply of suitable waste streams, and competing with higher-priority uses for that processed waste into biomethane for trucks, buses etc.

(Biofuels from freshly-grown crops are of course fine in principle but in practice require large scale fossil fuel inputs for fertilisers and other agricultural inputs. And the issues with chopping down forests to plant biofuel crops have been scandalous in recent years - they can scarcely be called 'green'.)

With synthetic/e-fuels (ie generating CO2 and then combining it with hydrogen) the efficiency of converting renewably-generated electricity into a liquid fuel form is awful - maybe 15% efficient, versus 75-80% efficient if you just use the electricity to put into a vehicle battery in the first place.

So I don't think 'sustainable' liquid fuel substitutes are likely to be more than a very small scale solution. I think I saw a forecast somewhere recently that suggests they might be okay for about 2 percent of road transport applications but not much more.

Nigel

 

[tthomson]

On 7/25/2023 at 3:50 PM, stillp said:

Some electric motors can achieve 95% efficiency under some circumstances. That's neglecting the losses in the control system.

What about all the energy wasted (and CO2 generated) for exploration, production, transportation, refining, and distributing materials for batteries, as well as the manufacture and later disposal of those batteries?

Pete

The EV industry has backed the wrong battery technology. In doing so they have given China substantial control.

By comparison:

Sodium is ubiquitous, and could be extracted comparatively cheaply from seawater in the UK

Aluminium air batteries do not need pure Aluminium, and Aluminium is one of the most abundant elements on the planet.  Refining using geothermally produced electricity in Iceland would reduce the cost and efficiency losses. Even when the transportation of the Aluminium is added to the costs.

In response to improvements in efficiency of ICE vehicles, The maximum efficiency possible is approximately 40% for petrol, and for diesel approx 45% The physics of the technology defines this. Any efficiency improvements are related to reducing energy losses in taking the power to the road from the engine, so in real petrol vehicles the max is around 35% and for diesel 40% for perfectly setup and designed vehicles. (Not a typical road car). So if we are to compare technologies, we are discussing 40% efficiency for ICE  versus 95% for Electric. All the other "efficiencies" are reduction in losses, and can apply to any vehicle type.

[RobH]

You are absolutely right TT but measuring 'efficiency' in that way is pretty meaningless I think as it considers only one tiny aspect of the equation. It only accounts for the amount of useful energy that can be extracted from the fuel source. It takes no account of anything else - vehicle weight for instance  - and neither does it include the energy and resources to be used in building a viable re-charging network to replace the fairly simple hydrocarbon-fuel one, which I believe to be the 'elephant-in-the-room'. 

Liquid fuels are more efficient in a different way since they pack much more energy density into a given volume and weight, allowing the vehicle to require less energy to move, so the real overall calculation becomes rather more complicated.  

Having said that, the only thing that really matters to the user is the cost-per-mile and even that cannot take into account the convenience of being able to 'recharge' in a couple of minutes, in the case of ICE, for around three times the average BEV range. The cost calculation is also skewed by the different  levels of taxation levied. 

Volvo have admitted that in terms of total CO2 emissions including construction, it will take 98000 miles before their BEV breaks even with the equivalent ICE car.  I don't know whether that assumes 100% renewable electricity but if not the figure gets much worse, as we only get about 20% that way at present.  As I see it, the whole net zero thing is a giant con trick which gullible MPS bought in to without understanding - or being told- the consequences for society. 

 

 

 

 

Edited August 20, 2023 by RobH

[Peter Cobbold]

Maybe zinc-air batteries will replace Li:  https://techxplore.com/news/2023-08-zinc-air-batteries-future-powering-electric.html

But they also need cobalt, and that is limited in supply.

Peter