hydrogen powered 240

[Laird Scooby]

I wondered if it was a typo Alan. As you rightly say though, the price of marine based foods is static so it matters very little on that part of the discussion, you still can't produce a viable amount of hydrogen (even Browns Gas hydrogen/"heavy" hydrogen"H-H-O) to alter the physical needs of the engine to consume fuel to do work.

The bit that gets me about all these renewable (and therfore cheaper) electricity solutions is when the bill drops through the letterbox, it is similar to the fish, it's still expensive!

[Othen]

Originally Posted by Laird Scooby

The bit that gets me about all these renewable (and therfore cheaper) electricity solutions is when the bill drops through the letterbox, it is similar to the fish, it's still expensive!

... it is much worse than that Dave: the green levies that you and every other family in the country pays come to about £200/household. This money is used to subsidise green initiatives whether they are sensible or not.

Here is an example for you: about 6 years ago a contractor knocked my door and offered to install an electric car charging point in my garage for free (free to me, not free to the nation of course). An electrician showed up a few days later and fitted a domestic EV charging point, which took him about 30 minutes (I could have fitted it myself of course). The cost to the government was £1339.61 (I'm looking at the contractor's invoice as I type this).

The EV charging point has never been used (I don't have an electric car, as I explained to the contractor when he called) and the reading on the meter (that is monitored by some civil servant, somewhere) is still 0.0000. I suspect the government met some EU green energy target of installing so many EV charging points in a year, the contractor didn't mind because he grossly overcharged for his time (£120 for the survey, which took 2 minutes, £216 for the installation, which took 30 minutes), I didn't really care either way because the money would have just been wasted regardless... who lost? The ordinary family paying their gas and electricity bills of course.

Ho hum.

[Othen]

Good morn Dave,

I noticed on the 700 section of the forum a similar discussion that was starting to become a bit heated - needlessly I thought, and I have said so - hence I thought I'd avoid that for a little while. I thought you might appreciate these two little snippets I found (after a 6 mS search on the internet). This is all about energy density when it comes to vehicles (where one has to carry the fuel around, except in electric trains and trams of course). The first bit compared current lithium batteries with petrol:

A lithium-ion battery pack has about 0.3 MJ/kg and about 0.4 MJ/liter (Chevy VOLT). Gasoline thus has about 100 times the energy density of a lithium-ion battery. ... With the ratio about 5 (my explanation: due to the better energy efficiency of the electric motor), a battery with an energy storage density 1/5 of that of gasoline would have the same range as a gasoline-powered car.

The second compares hydrogen (used via a fuel cell and electric motors) to diesel for heavy trucks:

Another advantage is hydrogen’s energy density. Diesel has an energy density of 45.5 megajoules per kilogram (MJ/kg), slightly lower than gasoline, which has an energy density of 45.8 MJ/kg. By contrast, hydrogen has an energy density of approximately 120 MJ/kg, almost three times more than diesel or gasoline. In electrical terms, the energy density of hydrogen is equal to 33.6 kWh of usable energy per kg, versus diesel which only holds about 12–14 kWh per kg. What this really means is that 1 kg of hydrogen, used in a fuel cell to power an electric motor, contains approximately the same energy as a gallon of diesel. Taking this into consideration, Nikola claims its vehicles can get between 12 and 15 mpg equivalent, well above the national average for a diesel truck, which is around 6.4 mpg.

So, a petrol/diesel has about 5 times the usable energy of a lithium battery (per unit mass), and a hydrogen cell electric vehicle is about 2-3 times as much again.

A simple conclusion is that for trucks and plant machines batteries are never going to have sufficient energy density to work (without a 30 ton truck weighing 60 tons) - and for commercial vehicles the hydrogen infrastructure might well be workable.

For domestic use hydrogen would be less suitable because of the distribution and storage problems.

Alan

[Laird Scooby]

Ah, yeah, something like that Alan!

The one major flaw with the bits you've just relayed (i saw something similar recently online) is the weight of the hydrogen fuel cells. I may be slightly off beam here but as i understand it, they need to be very thick and heavy metal to contain the hydrogen. The ratio could be totally wrong but for the purposes of the discussion it's a starting point, it would take say a 9kg vessel to safely store 1kg of hydrogen on a large commercial vehicle.

Currently those vehicles have an approximate consumption of diesel of ~7mpg and a range of ~800 miles due to 100+ gallon fuel tanks. Let's make the sums easy and call it a 120 gallon diesel tank and call it a total weight (tank and fuel combined) of 120kg using an Rd of 0.8kg/L for the diesel and the rest is the weight of the fuel tank, either plastic or metal.

Using your figures for the hydrogen and an equivalent consumption of approximately double the mileage per kg, we'd still need 50kg of hydrogen for the same range. That's fine on the face of it until you consider the tank it has to be stored in with an assumptive ratio of the tank being 9 times the weight of the fuel so a full tank of hydrogen would be ~500kg. That's ~380kg less payload, not much in the great scheme of things i agree but it reduces the efficiency of the truck overall as that 380kg of product would need to go on the next truck.

This means the payload of each truck would need to increase or we need more trucks. However more trucks wouldn't necessarily be a problem because they'd be operating more cleanly.
The not-quite-other-side of this is that it reduces the viability of using hydrogen to power commercial vehicles.

The other thing is i have little idea how hydrogen fuel cells are replenished - if a truck enters the UK at Dover for example with a near full hydrogen fuel cell and by a circuitous route gets to say Edinburgh and is running on empty, how quickly can the fuel cell be refilled/exchanged?

[Clifford Pope]

There's another factor that fortunately has not arisen yet, and that is the peculiar public over-reaction to a single tragic disaster.
Remember the Hindenburg airship crash? (well, perhaps not literally)
Hydrogen got the blame, so the development of airships was stopped in its tracks for half a century.
Yet it was the cellulose proofing on the fabric gas containers that caught fire, and fewer people died than in an average modern plane crash. Most people jumped out when the flaming airship hit the ground, gently, because of the hydrogen.
"Cladding" on tower blocks has gone the same way.

The authorities must now be excessively risk-aware, if not scared, of one bad accident occuring with an autonomous car, or an exploding hydrogen powered lorry, killing the whole project.

[Othen]

Originally Posted by Laird Scooby

Ah, yeah, something like that Alan!

The one major flaw with the bits you've just relayed (i saw something similar recently online) is the weight of the hydrogen fuel cells. I may be slightly off beam here but as i understand it, they need to be very thick and heavy metal to contain the hydrogen. The ratio could be totally wrong but for the purposes of the discussion it's a starting point, it would take say a 9kg vessel to safely store 1kg of hydrogen on a large commercial vehicle.

Currently those vehicles have an approximate consumption of diesel of ~7mpg and a range of ~800 miles due to 100+ gallon fuel tanks. Let's make the sums easy and call it a 120 gallon diesel tank and call it a total weight (tank and fuel combined) of 120kg using an Rd of 0.8kg/L for the diesel and the rest is the weight of the fuel tank, either plastic or metal.

Using your figures for the hydrogen and an equivalent consumption of approximately double the mileage per kg, we'd still need 50kg of hydrogen for the same range. That's fine on the face of it until you consider the tank it has to be stored in with an assumptive ratio of the tank being 9 times the weight of the fuel so a full tank of hydrogen would be ~500kg. That's ~380kg less payload, not much in the great scheme of things i agree but it reduces the efficiency of the truck overall as that 380kg of product would need to go on the next truck.

This means the payload of each truck would need to increase or we need more trucks. However more trucks wouldn't necessarily be a problem because they'd be operating more cleanly.
The not-quite-other-side of this is that it reduces the viability of using hydrogen to power commercial vehicles.

The other thing is i have little idea how hydrogen fuel cells are replenished - if a truck enters the UK at Dover for example with a near full hydrogen fuel cell and by a circuitous route gets to say Edinburgh and is running on empty, how quickly can the fuel cell be refilled/exchanged?

Hi Dave,

An interesting discussion. I don't think you can be right about the weight of the storage container being 9 times that of the hydrogen. When I was diving in the Army the hydrogen for the Vixen torch came in the same type of cylinders as the oxygen (and does similar industrial gases such as acetylene, and argon). I don't have the details, but the cylinders certainly don't weigh 9 times that of their contents, of that I am absolutely sure (having carried plenty of full and empty ones during diving operations). The difference will scale up as well, a container for 100kg of hydrogen will not weigh anything close to 100 times as much as one for 1kg of hydrogen.

The article comparing hydrogen to diesel for trucks is here:

https://rmi.org/run-on-less-with-hydrogen-fuel-cells/#:~:text=Another%20advantage%20is%20hydrogen's%20e nergy,more%20than%20diesel%20or%20gasoline.

... there is no mention of that weight penalty; I am no expert on this, but I rather think the weight penalty would have been listed as a demerit if it was a factor of 9 times the fuel load (I'm thinking the decimal point is probably in the wrong place, the pressure vessel might typically weigh 0.9 times as much as its contents).

The article talks about the logistics of refuelling trucks being less difficult to solve than for domestic cars. I agree with this, it is easy to imagine dedicated truck stops for hydrogen, also all truck drivers are professionals so it would be quite easy to include fuel handling in their certification.

Again, I'm no expert at this, but I can see it being worth the haulage industry's time to solve the logistics, whereas for domestic car users that might be far more difficult. Plenty of people put diesel in their petrol cars (and vice versa) now, so there would have to be some more fool-proof way opf refuelling with hydrogen before it was ready for domestic consumption. Perhaps we go back to having dedicated attendants at gas stations?

It does seem to me though that the battery EV cannot be the future for trucks and plant machines because the energy density is just too low (and always will be). If fossil fuels become unacceptable (or run out, but that won't happen for quite some time) then another means of storing energy must be found. We can make plenty of energy from nuclear/solar/wind, and there will very often be surpluses because the weather isn't that obliging, but electricity is really difficult to store. Battery storage isn't really an answer because by its very nature have to be DC and low voltage, which is no good for transmission because of the current losses. Hydrogen is really plentiful, pretty easy to produce and really clean when we turn it back into energy. It sort of has the be the answer (but there will be lots of logistic issues to solve on the way).

This discussion is an aside from our normal old Volvo car chat.

Alan

[Othen]

Originally Posted by Clifford Pope

There's another factor that fortunately has not arisen yet, and that is the peculiar public over-reaction to a single tragic disaster.
Remember the Hindenburg airship crash? (well, perhaps not literally)
Hydrogen got the blame, so the development of airships was stopped in its tracks for half a century.
Yet it was the cellulose proofing on the fabric gas containers that caught fire, and fewer people died than in an average modern plane crash. Most people jumped out when the flaming airship hit the ground, gently, because of the hydrogen.
"Cladding" on tower blocks has gone the same way.

The authorities must now be excessively risk-aware, if not scared, of one bad accident occuring with an autonomous car, or an exploding hydrogen powered lorry, killing the whole project.

That is a good point Clifford, particularly about thermal cladding having created an absurdly risk averse culture.

I think I mentioned the Hindenburg above, you are right, the newsreels of the airship burning have created a mindset that would be very anti-hydrogen. Have a look at what I wrote above though: I wonder whether we have any real choice if we want to carry on living our lives the way we do, and the human population keeps rising as it does? We won't be short of energy because of the sun (solar and wind) and nuclear energy, but the problem is storing it without too much loss, reasonably safely and without causing too many environmental impacts when we turn it back into work.

Alan

[Laird Scooby]

Originally Posted by Clifford Pope

There's another factor that fortunately has not arisen yet, and that is the peculiar public over-reaction to a single tragic disaster.
Remember the Hindenburg airship crash? (well, perhaps not literally)
Hydrogen got the blame, so the development of airships was stopped in its tracks for half a century.
Yet it was the cellulose proofing on the fabric gas containers that caught fire, and fewer people died than in an average modern plane crash. Most people jumped out when the flaming airship hit the ground, gently, because of the hydrogen.
"Cladding" on tower blocks has gone the same way.

The authorities must now be excessively risk-aware, if not scared, of one bad accident occuring with an autonomous car, or an exploding hydrogen powered lorry, killing the whole project.

The Hindenburg was a little before my time.

Would it really bother the likes of Ford though? Cast your mind back to the Ford Pinto, Mercury Bobcat and have a read of this :

https://www.autosafety.org/ford-pinto-fuel-fed-fires/

Not mentioned in that but equally a Ford problem was the ignition switch on certain models, Mercury in particular but other models from the Ford portfolio used the same component - an ignition switch that could cause fires by overheating, even when the vehicle wasn't in use.

In both cases, there was a cheap and easy fix available, unit cost almost negligible although obviously with 500k+ units at the earliest point most of this was known about, not quite so cheap.

People still ran petrol cars and still bought Fords. I'm not saying your point is invalid, far from it, but it seems the general public have become more forgiving and have shorter memories these days.

Will all those dyed-in-the-wool greenies stick to their beliefs and buy hydrogen powered vehicles because they're cleaner? Probably.

Will they care they're driving a potential human BBQ on wheels? Probably not.

Will all their greenie-vegan-mates be queuing up for a "long-pig-burger"? Hell, yeah!

The last comment is obviously tongue-in-cheek but it does make you wonder, if there was a hydrogen based disaster and lives were lost, what stance would the eco-warriors take?

[Laird Scooby]

Originally Posted by Othen

Hi Dave,

An interesting discussion. I don't think you can be right about the weight of the storage container being 9 times that of the hydrogen. When I was diving in the Army the hydrogen for the Vixen torch came in the same type of cylinders as the oxygen (and does similar industrial gases such as acetylene, and argon). I don't have the details, but the cylinders certainly don't weigh 9 times that of their contents, of that I am absolutely sure (having carried plenty of full and empty ones during diving operations). The difference will scale up as well, a container for 100kg of hydrogen will not weigh anything close to 100 times as much as one for 1kg of hydrogen.

The article comparing hydrogen to diesel for trucks is here:

https://rmi.org/run-on-less-with-hydrogen-fuel-cells/#:~:text=Another%20advantage%20is%20hydrogen's%20e nergy,more%20than%20diesel%20or%20gasoline.

... there is no mention of that weight penalty; I am no expert on this, but I rather think the weight penalty would have been listed as a demerit if it was a factor of 9 times the fuel load (I'm thinking the decimal point is probably in the wrong place, the pressure vessel might typically weigh 0.9 times as much as its contents).

The article talks about the logistics of refuelling trucks being less difficult to solve than for domestic cars. I agree with this, it is easy to imagine dedicated truck stops for hydrogen, also all truck drivers are professionals so it would be quite easy to include fuel handling in their certification.

Again, I'm no expert at this, but I can see it being worth the haulage industry's time to solve the logistics, whereas for domestic car users that might be far more difficult. Plenty of people put diesel in their petrol cars (and vice versa) now, so there would have to be some more fool-proof way opf refuelling with hydrogen before it was ready for domestic consumption. Perhaps we go back to having dedicated attendants at gas stations?

It does seem to me though that the battery EV cannot be the future for trucks and plant machines because the energy density is just too low (and always will be). If fossil fuels become unacceptable (or run out, but that won't happen for quite some time) then another means of storing energy must be found. We can make plenty of energy from nuclear/solar/wind, and there will very often be surpluses because the weather isn't that obliging, but electricity is really difficult to store. Battery storage isn't really an answer because by its very nature have to be DC and low voltage, which is no good for transmission because of the current losses. Hydrogen is really plentiful, pretty easy to produce and really clean when we turn it back into energy. It sort of has the be the answer (but there will be lots of logistic issues to solve on the way).

This discussion is an aside from our normal old Volvo car chat.

Alan

I don't know if it came across in my post Alan but my figures were very much guessed at. They were based on my experience of LPG tanks that are considerably heavier than the LPG that goes into them, for something that only holds a kilo or 2 of hydrogen then i daresay the ratio is closer to unity than in the LPG tanks and unless i've totally misunderstood something, hydrogen needs to be stored under higher pressure than LPG so needs to withstand that pressure from a large quantity.

As for having pump attendants at filling stations, the local Shell station at Fiveways tried that a few years back.

At the time V-Power was new and was still doing what it said in the blurb (it no longer does ) so i was using that.

I pulled up to a pump to refuel and the attendant jumped out and grabbing the (basic) diesel pump nozzle, offered to fill my tank for me.
My vehement refusal shocked him. He still didn't get it when i grabbed the petrol nozzle

I point blank asked him as i was returning from paying if he'd worked out why i didn't want a tank full of diesel and he admitted he had no clue.

With that kind of mentality, attended service isn't necessarily going to be the answer!

[Laird Scooby]

Originally Posted by Othen

We won't be short of energy because of the sun (solar and wind) and nuclear energy, but the problem is storing it without too much loss, reasonably safely and without causing too many environmental impacts when we turn it back into work.

Alan

Simple answer there Alan, store the electricity in batteries and use inverters to turn it back into AC to be stepped up by transformers for power transmission.

Think of it as a UPS on steroids.