Reverse cycle air con / heating info

John100156 said:
Mmm as it does with all new technologies: I expect when internal combustion engines were first developed people would have said it would never catch on as there are no fuel stations which would have to have huge buried time bombs below the forecourt, but it did relatively safely. With the alternative form of transport at that time all you needed was a bale of hay and some water, and the by-product helped grow some lovely strawberries :).

Then someone realised they could make a bob or two..... Same with EV charging...... Get the technology to work first with an abundant energy source (H2) and the rest WILL inevitably follow!

Anyway, to close this out (apologies of course to the OP for deviating) I suppose it could go H2/EV motors or H2/IC motors, I suppose we will just have to wait and see :).
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Using H2 with a fuel cell and electric motors is considerably more efficient than burning H2 in an internal combustion engine.
The former is about 80% efficient. The latter about 25% to 30%.

If H2 is made from electricity, the whole chain from electricity in to electric motive power out (leccy -> electrolysis -> compression/cooling -> distribution -> car -> fuel cell -> motor) is considerably less efficient than going leccy -> battery -> motor.

H2 could be interesting for airplanes where weight has a impact on fuel cost. H2 is the best fuel in terms of power/weight ratio short of nuclear fission and fusion.

Paris is going Biomethane (also called "Renewal Natural Gas"/RNG) for its bus fleet. It also has some LNG busses, and hybrid busses.
There are a quite a lot of EV taxis, more hybrid taxis. And just a few H2 taxis (Toyota Mirai).

Shenzhen in China has gone 100% electric for all its busses (~16,000 of them) and taxis (~22,000).
Most of the trucks on its roads are also electric. A lot of long distance intercity transport trucks use gas.

Also battery cost is dropping rapidly and capacity per kg or m^3 is increasing which will make battery powered artics very useable.
Current offerings have a range of 500km fully loaded (40T) with a 20-80% recharge time of 20 minutes.
They are expensive, but if charging is done at "home" they can rapidly pay back the extra initial cost of acquisition compared to a diesel truck.

So, no. I don't think H2 is going to take off for road transport, nor for cars, nor for trains.

Whether it will take off (see what I did there), for planes I don't think so either. I think some other fuel will predominate. In the short term it will be some kind of bio jet fuel running in engines which are basically the same as we have now.
 
westernman said:
Using H2 with a fuel cell and electric motors is considerably more efficient than burning H2 in an internal combustion engine.
The former is about 80% efficient. The latter about 25% to 30%.

If H2 is made from electricity, the whole chain from electricity in to electric motive power out (leccy -> electrolysis -> compression/cooling -> distribution -> car -> fuel cell -> motor) is considerably less efficient than going leccy -> battery -> motor.

H2 could be interesting for airplanes where weight has a impact on fuel cost. H2 is the best fuel in terms of power/weight ratio short of nuclear fission and fusion.

Paris is going Biomethane (also called "Renewal Natural Gas"/RNG) for its bus fleet. It also has some LNG busses, and hybrid busses.
There are a quite a lot of EV taxis, more hybrid taxis. And just a few H2 taxis (Toyota Mirai).

Shenzhen in China has gone 100% electric for all its busses (~16,000 of them) and taxis (~22,000).
Most of the trucks on its roads are also electric. A lot of long distance intercity transport trucks use gas.

Also battery cost is dropping rapidly and capacity per kg or m^3 is increasing which will make battery powered artics very useable.
Current offerings have a range of 500km fully loaded (40T) with a 20-80% recharge time of 20 minutes.
They are expensive, but if charging is done at "home" they can rapidly pay back the extra initial cost of acquisition compared to a diesel truck.

So, no. I don't think H2 is going to take off for road transport, nor for cars, nor for trains.

Whether it will take off (see what I did there), for planes I don't think so either. I think some other fuel will predominate. In the short term it will be some kind of bio jet fuel running in engines which are basically the same as we have now.
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I think you’d better have a chat with JCB.
 
Mmmm I wonder why our top Uni and NPL are wasting significant funding on this, you should contact them, you could save them a fortune:). The latter is up-sizing their H2 filling station this year. I still think it will have to go H2 at some stage.....

Anyway, a HNY to you all....!
 
John100156 said:
Mmmm I wonder why our top Uni and NPL are wasting significant funding on this, you should contact them, you could save them a fortune:). The latter is up-sizing their H2 filling station this year. I still think it will have to go H2 at some stage.....

Anyway, a HNY to you all....!
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Maybe they're being paid to do it? Not unusual for Unis to take on paid research.

HNY to you too.
 
One report found in the UK that 23 EV cars caught fire due to a faulty battery from January 1 to March 31, 2023. I expect these statistics to rise as production increases.

Bedfordshire Fire and Rescue reports:
Data obtained by Air Quality News through a Freedom of Information (FOI) request revealed that in 2019 the London Fire Brigade dealt with 54 electric vehicle fires compared to 1,898 petrol and diesel fires. Although these fires remain rare, when they do occur, they can be extremely dangerous.

During an electric vehicle fire, over 100 organic chemicals are generated, including some incredibly toxic gases such as carbon monoxide and hydrogen cyanide – both of which are fatal to humans.

Farming and Construction Vehicles Set for Hydrogen-Powered Revolution​

Tractors, diggers and forklifts powered by hydrogen will help building sites and agricultural businesses go greener under government plans set out on 27 March 2024.

A switch to cleaner technology will allow construction and farming, 2 key parts of the economy, decarbonise faster.

New regulations, set out in a consultation launched today, would allow hydrogen-powered tractors, diggers and forklifts to be used on roads in Great Britain. The consultation will run for 4 weeks, closing on 24 April 2024.

Technology and Decarbonisation Minister, Anthony Browne, said:

Allowing hydrogen-powered tractors, diggers and forklifts to use our roads is a common-sense move to help reduce emissions.
These proposals are an important part of our plan to decarbonise transport in the UK, with skilled jobs in British companies helping roll out this cutting-edge hydrogen technology, making it more affordable and commonplace.
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Hydrogen-powered construction and farming vehicles can improve the sustainability of the sector by reducing emissions from the tailpipe.

The launch of the consultation comes after the government issued construction equipment manufacturer JCB with a vehicle special order last year, giving the company permission to test its hydrogen-powered diggers on UK roads.

The proposals will expand this permission permanently across the sector, meaning manufacturers can more easily scale up production of sustainable equipment where battery electric power is not practical.

Alongside electric, hydrogen is one of many sustainable fuel sources that could accelerate decarbonisation. Projects such as the government-funded Tees Valley Hydrogen Hub are showing how green hydrogen can be utilised across the transport sector, creating jobs and apprenticeships in the region and boosting the economy.

We definitely need to develop this technology IMO; ignoring those whom said in the past: 'you will suffocate if you take the Train'.... :)
 
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John100156 said:
One report found in the UK that 23 EV cars caught fire due to a faulty battery from January 1 to March 31, 2023. I expect these statistics to rise as production increases.
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You didn't provide a link, but for context there are around 100,000 vehicle fires reported in the UK every year. Also for context, there are around 1 million EVs in the UK currently.

Hybrids are most likely to catch fire
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John100156 said:
During an electric vehicle fire, over 100 organic chemicals are generated, including some incredibly toxic gases such as carbon monoxide and hydrogen cyanide – both of which are fatal to humans.
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From petrol car fires:

The quantitative analysis of the smoke gases from the full-scale fires showed that emissions with a potentially negative impact on the environment, or chronic toxic effect on humans, were produced in significant quantities. These emissions included HCl, SO2, VOCs (e.g. benzene), PAHs, and PCDDs/PCDFs.
 
Clash said:
It was supported in the video I linked. But if you need pictures, here's one from this article. Which compares with BEV at a minimum of 80%. And the below chart doesn't apply full generation and transmission losses wrt hydrogen production but does for vehicle charging, so the figure is closer to 85% than 80% if comparing like with like.

Taxes and charges have nothing to do with efficiency. The internal combustion engine is extremely inefficient in delivering the power produced by the engine to the wheels.

View attachment 187125
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Look the attendees of this Forum are generally not numpty's.

So in Post 47 you state EVs are 83 - 93% efficient (with no context), yet here in post 53 you show a graph suggesting (at least) EVs are 38% efficient (although a bland statement of 'Watts', a measurement of Power, is in this context actually completely meaningless - the discussion here is about Energy consumption and efficiency not Power).

Now referring back to post 47 wasn't that close to where you placed ICEs ~ 25 - 35% ?

Just an observation, but shows how important context is, rather than simply shouting loudest therefore must be right - that is how the woke world works.
 
superheat6k said:
Look the attendees of this Forum are generally not numpty's.

So in Post 47 you state EVs are 83 - 93% efficient (with no context), yet here in post 53 you show a graph suggesting (at least) EVs are 38% efficient (although a bland statement of 'Watts', a measurement of Power, is in this context actually completely meaningless - the discussion here is about Energy consumption and efficiency not Power).

Now referring back to post 47 wasn't that close to where you placed ICEs ~ 25 - 35% ?

Just an observation, but shows how important context is, rather than simply shouting loudest therefore must be right - that is how the woke world works.
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His graph shows the efficiency of using hydrogen to power an electric vehicle via a fuel cell (i.e. a FCV, such as Toyota Mirai) which is overall about 38% efficient.

If you use hydrogen in an ICE engine than you have an overall efficiency of 65% x (25 - 35%). I.e. 16 - 22% overall.

A battery electric vehicle is 80% efficient (according to the link report).

To piss off EVanglists, here is a report about well to wheel efficiency of EVs when the leccy is coming from a diesel powered generator!
Comparison of the Overall Energy Efficiency for Internal Combustion Engine Vehicles and Electric Vehicles.
 
We have moved on a bit since 2020.... It is relatively simple to search for links nowadays to support any side of a debate.

I confess, that I am no expert in these fields, but I have been continuously employed for over 43 years now as a mechanical and electrical consultant designing services installations to: pharmaceutical, medical and scientific research facilities, mainly in the UK but also abroad. We very often get involved in ground breaking scientific research development projects, some of which don't hit the mainstream for 5-8 Years.

So, if World leading experts employed at NPL and Imperial College are both investing in H2 development (among others) I suspect it will in time come to fruition, even used in cars, as a clean and most abundant Energy source! I for one do hope so.
 
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