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Hydrogen Station Gets a Reality Check

44K views 476 replies 49 participants last post by  M4rm1t3 
#1 ·
The 100D spent the night nervously contemplating which fuel is smarter (hoping the smokers in the car park didn't get any closer) - then set course for Edinburgh.

Be nice if these places provided a fueling facility for real zero emissions vehicles with your tax money, rather than unicorns.

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#4 ·
#13 ·
Absolutely. In fact these stations pump a small buffer tank up to 800 bar in order to bring the car's tank up to 700 bar without the equilisation of pressure reducing the flow down to nothing. If that buffer tank is empty and you are last in the queue, prepare to wait.

And as you say, they are a stop-gap solution. As are the sites powered by renewables, which as we showed before cannot realistically supply more than a handful of cars per day.
 
#14 ·
Did you follow this itinerary or go off piste?

Personally I'd probably have gone straight to Charnock Richard (can't be much more than 200 miles which is childs play in a 100D) and then either done a single long stop there, or split into two short stops one at Charnock and then one at Abington.

But by Tesla Nav standards it's certainly not a silly suggestion, which makes a nice change!
 
#15 ·
Did you follow this itinerary or go off piste?
That was a hypothetical "what if" sat-nav plot to see what would be needed to drive from that hydrogen station to Edinburgh. Actually I had to go to work :(

However it did give me an idea that perhaps we should get a convoy of Teslas and do such a point-to-point trip to another hydrogen station up north, just for a giggle.

As I was staying in that hotel overnight (and as it doesn't have a charging point) I started the trip with about 75%, having driven up from Winchester. This is why the nav was plotting a route with a quick stop at Warwick.

I tried the same again this morning from home, having done a full charge last night, and this time it went straight to Charnock Richard. However, I was giving it the beans on the way up the A34 to work and several times the nav warned that I needed to slow down in order to make it to the charge point. That seems strange as it could have dynamically re-plotted the course to call in at Warwick as well but obviously they haven't thought of that yet.

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#18 ·
I looked a bit more into those cylinders at the back of the site. 120 in total and I recon they are K sized ones, as per here High Purity Hydrogen Cylinder | BOC Shop

The data sheet says each contains 7.21 m^3 of hydrogen. I presume that means at STP, which would therefore weigh 648 grammes.

The data sheet also says each cylinder has 65 kg gross weight. Therefore the ratio of total weight to contained gas is virtually 100:1 (this does not account for the residual gas that will not come out when depleted, so in reality is a bit worse).

120 cylinders contain 77.76 kg of gas, which is enough to fill 15 cars.


Furthermore, each cyclinder costs £39.17 exc delivery from BOC. It needs 8 to fill a car with a 5kg tank = £313.36 total.
 
#19 ·
That datasheet has a max pressure of 175, so not exactly the same.

Using this source of a graph of hydrogen density vs pressure (first one I found and it looks vaguely plausible):

Outer dimensions of the cylinder are 1460x230, so volume 1.46*.115*.115*pi = 0.0607; call the inner volume 0.06 to be generous. At 175 bar it's about 12kg/m^3, so the cylinder holds .72kg - very close to your calculation, specially as I've overestimated the contained volume. At 500bar it's about 31kg/m^3, so 1.86kg per cylinder; 120 cylinders = 223kg = 44 cars. At 700 bar (imagining one of those cylinders being the tank in a car) it's 40kg/m^3, so each cylinder holds 2.4kg.

I think the cylinders on the pallets must be a bit bigger than these. Presumably the pallets are meant to fill the back of a typical lorry (max 2.55m wide), so we'd expect more like 2m long rather than 1.46m.

Going at it another way, max size lorry is 12m long 2.55m wide; assume you're prepared to go 2m above loadbed height so total volume is 12*2.5*2=60m^3. Assume a set of cylinders gives 50% useful volume after accounting for the gaps between cylinders, so 30m^3 of gas; at 500 bar =930kg = 186 fills of a car. Probably these ones aren't quite so tall, but this gives a feel for the best you could manage on a standard delivery lorry and again it's coming out to similar numbers.

I'm also not sure how the cylinder gets to weigh as much as 65kg if it's a lightweight composite structure; maybe BOC's ones have a steel outer skin or something? But certainly the delivery lorry is going to weigh about the same whether full or empty.
 
#20 ·
Air Products PR states that this site gets deliveries from a hydrogen tube trailer which delivers hydrogen at 500 bar.

Supporting a Growing UK Hydrogen Infrastructure: Air Products’ High Pressure Tube Trailer Fleet Expansion and Permanent Fuelling Station Installation

Looking up details about this tube trailer I found this

Air Products launches hydrogen high-pressure tube trailers for European hydrogen infrastructure deployment - Renewable Energy Focus



Air Products launches hydrogen high-pressure tube trailers for European hydrogen infrastructure deployment - Renewable Energy Focus



http://photolibrary.airproducts.com/ImageViewer.aspx?uid=46B5F260167747CDA1D8150CAABC42BA&m=9


However this looks nothing like the cylinders in the compound on site. Do they transfer from this into the cylinders or have they given up on it and just bring in the old style ones?


Also:

“Munich, 25 September 2013 – Technology company The Linde Group has developed a new storage technology that will enable a much more efficient transport of larger amounts of hydrogen. The new solution works at a higher pressure of 500 bar (7,250 psi) and uses new, lighter storage materials to more than double the amount of compressed gaseous hydrogen (CGH2) that can be transported in a single truck load……
Each trailer features 100 lightweight composite storage elements developed in collaboration with xperion Energy & Environment GmbH. A single trailer can transport over 1,100 kilograms, or 13,000 normal cubic metres, of hydrogen gas. In addition, the trailers can now be filled and emptied in less than 60 minutes.”
 
#23 ·
There seem to be more different ways of transporting it than there are H2 stations out there!


Air Products PR states that this site gets deliveries from a hydrogen tube trailer which delivers hydrogen at 500 bar.

Supporting a Growing UK Hydrogen Infrastructure: Air Products’ High Pressure Tube Trailer Fleet Expansion and Permanent Fuelling Station Installation
That one talks about an upgrade from 200bar to 500bar. Maybe the red ones are the old ones?

Looking up details about this tube trailer I found this
That one seems to be USA-oriented, but has numerous options in it. Right at the end are some red cylinders superficially similar to the ones we are looking at, SmartFuel 8/16-cylinder hydrogen storage module.
That has 3000psig (approx 200bar) and 19kg in the 16-cylinder version, so 1.2kg per cylinder.

That doesn't give much more data, but does match up the photo of the 500bar trailer with the one you found in the streetview photo.


http://photolibrary.airproducts.com/ImageViewer.aspx?uid=46B5F260167747CDA1D8150CAABC42BA&m=9

However this looks nothing like the cylinders in the compound on site. Do they transfer from this into the cylinders or have they given up on it and just bring in the old style ones?
That photo (and the streetview one too) does look like the trailer has been left on site and the tractor unit driven away - which you wouldn't think they'd do while unloading if that takes only 60 minutes.

Maybe the red cylinders are a backup supply?
 
#24 ·
Wow, 6 of those cylinders on the top of an RV1!

Apparently this much H2 is needed to provide sufficient range for a full day of operation (16-18 hours).

Surprised they haven't had any empty buses topple over yet! :)



This case study from Ballard (pdf) makes interesting reading, especially as they try hard to make H2 sound compelling against BEV.

FUELING
Air Products provides hydrogen fuel and fueling facilities for the fleet operating in London. The hydrogen is generated in the Netherlands and then shipped across the English Channel as liquid hydrogen and trucked to the transit bus maintenance facility.

As of July 2015, more than 5,600 fillings had taken place, with over 96,000 kilograms of hydrogen supplied.

London operators are able to fill a bus from empty in less than ten minutes on average.

Today, the majority of hydrogen for transit bus fleets is produced by large-scale steam methane reforming (SMR). This is currently the most cost-effective method of hydrogen production. Longer term, hydrogen can be produced from renewable sources, such as excess wind or solar power, making the vehicle truly zero-emission on a
well-to-wheel basis.

Together, the eight buses have logged more than 132,000 hours of service, covering over 1.3 million kilometers.
...
On average, CHIC program buses consume approximately nine kilograms of hydrogen per 100 kilometers, which is more energy efficient than a diesel bus.
I imagine that the new diesel hybrid buses are cleaner (well-to-wheel) and more efficient than these.
 
#25 · (Edited)
This presentation is interesting:

http://www.hysolutions-hamburg.de/f..._Arxer_Hydrogen_Energy_Systems_FCB_WS2013.pdf

It talks about a station delivering 5000kg/day needing about 7 deliveries per day if using the high-pressure trailer (table on page 17), so the trailer holds about 700kg or 140 car fills - in line with our calculations.

Also talks about choice between leaving trailer on site or unloading to local storage.
 
#26 · (Edited)
I notice that all the Chesterfield Special Cylinders press releases and general stories go out of their way not to say how much this trailer can carry, so that is a good find.

I see from On the road with a fuel tanker driver | Locations | BP Magazine | BP that a petrol tanker carries 37,000 litres.

A Prius tank is 45 litres and it has an NEDC range of 1426 km. The Mirai has an NEDC range of 550 km so equivalent to 17.36 litres of the Prius. Therefore the petrol tanker carries 2132 equivalent fills.

EDIT

I see here there are bigger 44 tonne tankers of 42,800 litres.


Also a couple of other interesting snippets in that presentation:

- They use 5000 kg / day as the benchmark for a site. That's bang in line with the amount I calculated is needed per filling station for the equivalent of a supermarket PFS.

- A large refinery today needs 283,000 kg of hydrogen per day. That's over 1% of the hydrogen I calculated for the UK to switch to FCVs.
 
#27 ·
Just sharing some links for further reading:

That AirProducts presentation apparently came from a fuel-cell bus conference in 2013, several of the other presentations are interesting (bottom of page):

hySOLUTIONS: Downloadbereich / Mediathek

Looking for a more up to date info, that conference series seems to have morphed into a zero-emission bus conference, last year's one again having interesting presentations on both hydrogen and battery electric buses:

2016 ZEB Conference & FCB Workshop Presentations|Center for Transportation and the Environment
 
#29 ·
Highlights from reading the stuff linked above:
  • Compressor reliability is the big issue with these refuelling stations - several papers talking about it, recommending either multiple compressors for redundancy, or having the hydrogen delivered at 500bar so you don't need a compressor at all to fuel buses at 350bar (shame about the cars wanting 700bar).
  • Metering accuracy is also an issue.
  • The various designs for bus refueling stations all seem to be sized on the basis that you have a driver working for a whole shift (10pm-6am) moving the fleet through the refueling stations (taking 10-15 minutes per bus).
  • All sorts of stuff (en-route recharging etc.) being trialed in London.
  • Battery bus fleets being expanded much faster than hydrogen ones.

My new thought after reading tons of hydrogen propoganda:
  • The main justification for hydrogen seems to be that it can scale storage capacity better than batteries - batteries necessarily scale power/capacity together, while hydrogen can in theory scale the 'tank' cheaply while the expensive part stays the same if you only want to fill the tank slowly.
  • On that basis, there could perhaps be an argument that hydrogen is useful for capturing excess renewable generation on the grid - you'd have batteries for hour-to-hour levelling, but the hydrogen would be used for longer term storage - larger capacity, filled slowly.
  • The proponents of hydrogen say that you will thus have this surplus hydrogen that you can't readily store in batteries, and you should therefore use it to power FC buses.
  • If you assume for a moment that the hydrogen-for-long-term-storage argument has merit, is burning it in buses or cars actually efficient? If instead you just put the fuel cell along side the electrolyser (on some nice cheap piece of land rather than an urban bus station) and fed it back into the grid (and used battery buses) how would the efficiency compare? You've now got a charge/discharge cycle of a battery knocking off efficiency, but in a FCV you've got a fair proportion of that already (FC output is always buffered by a battery/supercap), and you've also got the heavy efficiency loss of compressing/decompressing as you move the hydrogen from tank to tank.
  • So even starting from a tank full of hydrogen, it seems unlikely to me that the efficiency of getting that hydrogen into a vehicle and using it there beats a static fuel cell and batteries in the vehicle.
  • Likewise, it seems unlikely that the vehicle-mounted fuel cells + small batteries + tanks + compressors etc. would work out cheaper than static fuel cells + larger batteries in the vehicles.
 
#30 ·
  • The main justification for hydrogen seems to be that it can scale storage capacity better than batteries - batteries necessarily scale power/capacity together, while hydrogen can in theory scale the 'tank' cheaply while the expensive part stays the same if you only want to fill the tank slowly.
Isn't this where flow batteries come into their own?
 
#34 ·
Certainly that's another potential competitor in the season-scale storage business. My guess would be that the contents of the tank is still quite expensive for most of the flow battery systems, though I don't know the numbers and there are many chemistries to choose from. Indeed, in one way of classifying things the active element of a flow battery counts as a fuel cell.
 
#36 · (Edited)
#37 ·
Apologies for hijacking the thread, but could not help but notice the fire extinguishers.

Hydrogen fueled fire.... powder hmmm that's so going to work, not!

CO2 is a bit better, being more dense to smother the fire as long as it's in a hole, otherwise the H2 will bubble up and continue to burn...
 
#39 ·
Apologies for hijacking the thread, but could not help but notice the fire extinguishers.

Hydrogen fueled fire.... powder hmmm that's so going to work, not!

CO2 is a bit better, being more dense to smother the fire as long as it's in a hole, otherwise the H2 will bubble up and continue to burn...
How about water? :rolleyes:
 
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