Hydrogen Argument...
Discussion
GT9 said:
TheDeuce said:
If hydrogen can in some way generate power in a very green way then great, lets build hydrogen power stations to power thousands of homes and cars.
Where are you getting the hydrogen from to 'generate' power? It either started life as a reformed hydrocarbon or as water cracked by electricity both of which consumed power that had already been generated. You can of course assume it's an imported commodity, but I'm not sure relying entirely on the import of hydrogen would be a sound economic or political strategy.TheDeuce said:
So far all the greenest ways of producing AND distributing hydrogen involve far more energy loss than putting the power straight in to the car.
The words 'so far' are superfluous in that sentence, the intrinsic efficiency is what it is and won't ever change significantly.I think HFC got a lot of attention and support early on because it sounded like the next natural evolution after petrol - no fumes and you can put it in the car as easily as petrol. On the face of it that sounds reasonable. But compared to BEV the efficiency is terrible, and that's before the cost of the infrastructure. That's why I see HFC in cars as a dead duck now. Potentially it could be useful in long range mass transport/freight, although I'd need to be convinced with some numbers on that.
NMNeil said:
HustleRussell said:
NMNeil said:
HustleRussell said:
NMNeil said:
GT9 said:
He's referring to the NOx produced from combusting it in an ICE.
And as usual the fact that there will be leakage of oil from the crankcase of an ICE engine past the piston rings, which it's then burned in the combustion chamber is ignored. The same for the PCV system and the valve guides. The engine will still be putting CO and CO2 into the atmosphere.The call is for 0 emissions, not close to 0.
Exhaust/tailpipe/engine emissions.
I was merely commenting on your statement in bold.
TheDeuce said:
I quite agree on both counts - that was my point really.
I think HFC got a lot of attention and support early on because it sounded like the next natural evolution after petrol - no fumes and you can put it in the car as easily as petrol. On the face of it that sounds reasonable. But compared to BEV the efficiency is terrible, and that's before the cost of the infrastructure. That's why I see HFC in cars as a dead duck now. Potentially it could be useful in long range mass transport/freight, although I'd need to be convinced with some numbers on that.
We are on the same page as usual!I think HFC got a lot of attention and support early on because it sounded like the next natural evolution after petrol - no fumes and you can put it in the car as easily as petrol. On the face of it that sounds reasonable. But compared to BEV the efficiency is terrible, and that's before the cost of the infrastructure. That's why I see HFC in cars as a dead duck now. Potentially it could be useful in long range mass transport/freight, although I'd need to be convinced with some numbers on that.
HFC cars will make some in-roads into the UK IMO.
I foresee 1 HFCV for every say 20-25 EVs.
GT9 said:
TheDeuce said:
I quite agree on both counts - that was my point really.
I think HFC got a lot of attention and support early on because it sounded like the next natural evolution after petrol - no fumes and you can put it in the car as easily as petrol. On the face of it that sounds reasonable. But compared to BEV the efficiency is terrible, and that's before the cost of the infrastructure. That's why I see HFC in cars as a dead duck now. Potentially it could be useful in long range mass transport/freight, although I'd need to be convinced with some numbers on that.
We are on the same page as usual!I think HFC got a lot of attention and support early on because it sounded like the next natural evolution after petrol - no fumes and you can put it in the car as easily as petrol. On the face of it that sounds reasonable. But compared to BEV the efficiency is terrible, and that's before the cost of the infrastructure. That's why I see HFC in cars as a dead duck now. Potentially it could be useful in long range mass transport/freight, although I'd need to be convinced with some numbers on that.
HFC cars will make some in-roads into the UK IMO.
I foresee 1 HFCV for every say 20-25 EVs.
I think I agree too.
Hydrogen fuelled ICE is going nowhere.
HFC will have a major role to play where power to weight ratio is not critical but long, near-continuous duty cycle is. There are already busses. In my opinion this will sector will grow to include most medium to heavy goods vehicles and construction machinery. It's made for the shipping industry too.
Flying vehicles is the tricky one. I envisage big batteries to provide the necessary power for take-off, ascent and landing, with a HFC fulfilling a kind of range extender role.
For the vast majority of domestic vehicles, BEV is all that is needed.
Hydrogen fuelled ICE is going nowhere.
HFC will have a major role to play where power to weight ratio is not critical but long, near-continuous duty cycle is. There are already busses. In my opinion this will sector will grow to include most medium to heavy goods vehicles and construction machinery. It's made for the shipping industry too.
Flying vehicles is the tricky one. I envisage big batteries to provide the necessary power for take-off, ascent and landing, with a HFC fulfilling a kind of range extender role.
For the vast majority of domestic vehicles, BEV is all that is needed.
HustleRussell said:
Flying vehicles is the tricky one. I envisage big batteries to provide the necessary power for take-off, ascent and landing, with a HFC fulfilling a kind of range extender role.
Conventionally-engined hydrogen-powered airliners are on the horizon.As with cars though, the low volumetric energy density of both liquid H2 and highly-pressurised gaseous H2 is the main issue.
The tanks required end up consuming a higher than desirable volume in the airframe.
Boyle's Law breaks down not far above 700 bar, so H2 storage as either a gas or a liquid is now close to its limit volumetrically.
The volumetric problem, if it becomes too limiting, could possibly be addressed by storing the energy as ammonia (NH3) and cracking that onboard the aircraft to feed H2 to the engines.
GT9 said:
Conventionally-engined hydrogen-powered airliners are on the horizon.
As with cars though, the low volumetric energy density of both liquid H2 and highly-pressurised gaseous H2 is the main issue.
The tanks required end up consuming a higher than desirable volume in the airframe.
Boyle's Law breaks down not far above 700 bar, so H2 storage as either a gas or a liquid is now close to its limit volumetrically.
The volumetric problem, if it becomes too limiting, could possibly be addressed by storing the energy as ammonia (NH3) and cracking that onboard the aircraft to feed H2 to the engines.
How much space do budget airliners use in the hold? Surely most internal flights are mostly carry-on and very little if no cargo?As with cars though, the low volumetric energy density of both liquid H2 and highly-pressurised gaseous H2 is the main issue.
The tanks required end up consuming a higher than desirable volume in the airframe.
Boyle's Law breaks down not far above 700 bar, so H2 storage as either a gas or a liquid is now close to its limit volumetrically.
The volumetric problem, if it becomes too limiting, could possibly be addressed by storing the energy as ammonia (NH3) and cracking that onboard the aircraft to feed H2 to the engines.
HustleRussell said:
Funny looking apology that
I was merely commenting on your statement in bold.
Not an apology, a clarification.I was merely commenting on your statement in bold.
Look how many times a PH member has said something along the lines of, "I can see the pollution form planes/trains/factories, so why can't I carry on with the little bit of pollution from my exhaust?" to detract from the original thread.
NMNeil said:
HustleRussell said:
Funny looking apology that
I was merely commenting on your statement in bold.
Not an apology, a clarification.I was merely commenting on your statement in bold.
Look how many times a PH member has said something along the lines of, "I can see the pollution form planes/trains/factories, so why can't I carry on with the little bit of pollution from my exhaust?" to detract from the original thread.
You’re being rude and dismissive towards me because of… things other PHers say? Do me a favour.
GT9 said:
I foresee 1 HFCV for every say 20-25 EVs.
no chance, not in the uk, that would be 80,000 HFC cars a year in the uk!The only reason to buy a (much more expensive, smaller, slower & less reliable) HFC passenger car vs a BEV passenger is because you need to be able to fill up very quickly, and of course that only works if their is somewhere to actually fill up locally, otherwise it takes longer to fill up because you have to drive miles to a filling station.
Given the BEV models that are coming out now as the big OE's really get behind the push to electrification, and seeing how the public charging network is maturing, i really can't see any more than 1 in 250 (8,000 PA) HFC passcars at absolute best case.....
Honda sold less than 2500 Clarity's in the US last year, down from just over 4000 from the year before. Toyota is in the same boat. Both Honda and Toyota were effectively giving these things away with free servicing and fuel for 3 or even 5 years! There is a reason why consumers arent buying into them.
Unless there is a big shift in the availability of filling stations, its going to be a niche at best. EV's arent perfect and might not be the right solution. But its still better for a lot of use cases vs hydrogen. At the moment at least.
Unless there is a big shift in the availability of filling stations, its going to be a niche at best. EV's arent perfect and might not be the right solution. But its still better for a lot of use cases vs hydrogen. At the moment at least.
Max_Torque said:
GT9 said:
I foresee 1 HFCV for every say 20-25 EVs.
no chance, not in the uk, that would be 80,000 HFC cars a year in the uk!The only reason to buy a (much more expensive, smaller, slower & less reliable) HFC passenger car vs a BEV passenger is because you need to be able to fill up very quickly, and of course that only works if their is somewhere to actually fill up locally, otherwise it takes longer to fill up because you have to drive miles to a filling station.
Given the BEV models that are coming out now as the big OE's really get behind the push to electrification, and seeing how the public charging network is maturing, i really can't see any more than 1 in 250 (8,000 PA) HFC passcars at absolute best case.....
Quite a lot can happen over 30 years though, and there may be some unforeseeable event/market condition/government policy that steers some people/fleets/etc. away from batteries.
granada203028 said:
Evanivitch said:
How much space do budget airliners use in the hold? Surely most internal flights are mostly carry-on and very little if no cargo?
I'm sure the hold is just as rammed as the cabin...Venisonpie: "The hydrogen will be supplied by air products, produced in the middle east using solar power as NH3 (ammonia) shipped to Purfleet and then chemically split into two gases both used in industry."
That elaborate supply chain will be very energy intensive; each step requires significant energy. On top of all that the gas will have to be compressed to 2 - 300 bar for transport. Then, if buses use similar starge tanks to FC cars, it will need boosting to 700 bar.
Has anyone worked out how many kWh will be consumed in the whole supply process for each kWh put into the vehicle?
That elaborate supply chain will be very energy intensive; each step requires significant energy. On top of all that the gas will have to be compressed to 2 - 300 bar for transport. Then, if buses use similar starge tanks to FC cars, it will need boosting to 700 bar.
Has anyone worked out how many kWh will be consumed in the whole supply process for each kWh put into the vehicle?
Mikehig said:
Venisonpie: "The hydrogen will be supplied by air products, produced in the middle east using solar power as NH3 (ammonia) shipped to Purfleet and then chemically split into two gases both used in industry."
That elaborate supply chain will be very energy intensive; each step requires significant energy. On top of all that the gas will have to be compressed to 2 - 300 bar for transport. Then, if buses use similar starge tanks to FC cars, it will need boosting to 700 bar.
Has anyone worked out how many kWh will be consumed in the whole supply process for each kWh put into the vehicle?
This video breaks down the efficiency losses involved from start to finish, Vs just putting the electricity directly in to a BEV battery: https://youtu.be/f7MzFfuNOtYThat elaborate supply chain will be very energy intensive; each step requires significant energy. On top of all that the gas will have to be compressed to 2 - 300 bar for transport. Then, if buses use similar starge tanks to FC cars, it will need boosting to 700 bar.
Has anyone worked out how many kWh will be consumed in the whole supply process for each kWh put into the vehicle?
You can see that as the numbers stack up there is no way HFC can ever be as energy efficient start to finish as BEV.
For the 1% or whatever vehicles that really can't cope with battery range it could make sense. Then again, for such a small number of vehicles just keeping to diesel could be said to be even more sensible..
Edited by TheDeuce on Tuesday 8th March 23:56
Evanivitch said:
granada203028 said:
Evanivitch said:
How much space do budget airliners use in the hold? Surely most internal flights are mostly carry-on and very little if no cargo?
I'm sure the hold is just as rammed as the cabin...Hold space will be at a huge premium. To be honest I think it's more likely that the longer-haul airframes will need a completely new design approach, like blended wing to increase internal volume without increasing drag too much.
To get a perspective on the scale of the problem, liquid hydrogen has a volumetric energy density at least 5 times lower than jet fuel, once you make allowance for the nature of the storage tank, possibly closer to 6.
Instead of taking up 5% of the airframe with fuel, it's now 30%. Liquid ammonia would reduce this back down to say 15%, but then you'd need a reactor to crack it at a flow rate of several litres per second, I have no idea how big that would be.
ETA: For the sake of completeness, gaseous hydrogen stored at 700 bar has a volumetric energy density of 7-8 times lower than liquid fossil fuel, once the tank wall thickness is taken into account. Multiple cylindrical tanks in an array will worsen this further. I don't think gaseous hydrogen will have any role to play in airliners.
The same problem exists for cars, which is why the HICE really has no future for regular passenger cars with any sort of acceptable range.
The magnesium paste storage idea isn't going to make much difference to this once you factor in the cartridge mechanism and the water tank. And that's ignoring the issue of each car consuming well over a ton of paste each year that needs to be returned for processing.
Edited by GT9 on Wednesday 9th March 10:46
TheDeuce said:
Mikehig said:
Venisonpie: "The hydrogen will be supplied by air products, produced in the middle east using solar power as NH3 (ammonia) shipped to Purfleet and then chemically split into two gases both used in industry."
That elaborate supply chain will be very energy intensive; each step requires significant energy. On top of all that the gas will have to be compressed to 2 - 300 bar for transport. Then, if buses use similar starge tanks to FC cars, it will need boosting to 700 bar.
Has anyone worked out how many kWh will be consumed in the whole supply process for each kWh put into the vehicle?
This video breaks down the efficiency losses involved from start to finish, Vs just putting the electricity directly in to a BEV battery: https://youtu.be/f7MzFfuNOtYThat elaborate supply chain will be very energy intensive; each step requires significant energy. On top of all that the gas will have to be compressed to 2 - 300 bar for transport. Then, if buses use similar starge tanks to FC cars, it will need boosting to 700 bar.
Has anyone worked out how many kWh will be consumed in the whole supply process for each kWh put into the vehicle?
You can see that as the numbers stack up there is no way HFC can ever be as energy efficient start to finish as BEV.
For the 1% or whatever vehicles that really can't cope with battery range it could make sense. Then again, for such a small number of vehicles just keeping to diesel could be said to be even more sensible..
Interesting video - thank you. As you say, it really spells out the cumulative ineffciencies in the hydrogen route.
However it does only address the electrolysis step. The production and supply route described by Venisonpie will add a lot more energy-consuming steps;
> Electrolysis, as per the video.
> Conversion to ammonia - presumably by the Haber process which requires very high pressures and temperatures so is energy intensive.
> Transport of the ammonia to the UK.
> Splitting the ammonia - probably requires heat and a catalyst.
> Separating the hydrogen from the nitrogen.
> Compression into tube trailers for transport (2 - 300 bar)
> Possible compression at fuelling station to pressure used by vehicle tanks (700 bar?)
The video talks of needing an input of 3.5 kWh for each kWh of useful energy in the FCEV. The above must add to that substantially.
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