Viewing 40 posts - 1 through 40 (of 250 total)
  • Hydrogen Cars – something doesn’t smell right
  • dmorts
    Full Member

    Maybe I’m being too cynicial here but the drive to run cars on hydrogen seems a backwards step when compared to EVs. The electricity required to charge EVs can be generated by numerous methods and people can even generate it themselves (with solar panels).

    Hydrogen would have to be supplied in much the same way as petrol or diesel….. is this the real reason behind its development? It’s simply a “greener” version of current fuels and can be taxed and controlled in the same way.
    You dont have to look far, e.g. hydrogen tech is being developed by one the Tory party’s largest donors, JCB. Also just saw a post about BMW’s hydrogen tech on Facebook, so many bots posting supportive 1 or 2 word comments it was laughable.

    jca
    Full Member

    Lithium batteries charge at something like 90% efficiency. Latest developments in hydrogen production are ~95% efficient, and require electricity and seawater (https://www.openaccessgovernment.org/green-hydrogen-produced-seawater-fuel-alternative/152420/). Hydrogen fuel cells are somewhere around 65% efficient at present, but improving. Time to refuel would be a lot less than recharging an EV.

    Main problem is that hydrogen is such a small molecule that it likes to escape from where it’s kept, and also to go bang. But LiON batteries aren’t exactly the nicest things to be sitting on top of…

    Drac
    Full Member

    Possibly better for heavy construction vehicles, still have my doubts for cars. Especially with the plans to move away from lithium.

    I don’t buy the conspiracy stuff though, similar nonsense was spread about EVs and cars running on water.

    ampthill
    Full Member

    That jca link is quite a big deal if it can be scaled up.

    On current tech you need 3 or 4 times more electricity to drive a mile on hydrogen compared to charging an ev

    dmorts
    Full Member

    It’s not a conspiracy it’s simply business. As petrol and diesel are phased out there will be a market opportunity. It could be captured completely by EVs but if you want a share you could push your own solution. A solution that requires a less undisruptable commodity (hydrogen) could give you a lot of control and long term payback on your investment.
    While electricity is mostly supplied by energy companies, it can be made in different ways and you can make it yourself. So I see it as more disruptable from an investment point of view.

    It does become a bit circular in the arguments as we need investment to make either solution work. But I don’t think those pushing hydrogen are doing so because it’s green

    clubby
    Full Member

    Friend works in oil regulation and lots of oil and gas companies investing in it. As a fuel it’s a lot easier to store than electricity. Production could be solar/tide/wind then stored in tanks rather than huge battery arrays. Possibility to use existing gas networks for distribution. As mentioned earlier, batteries needed for haulage/heavy industry use would be prohibitively massive and take too long to charge. Hydrogen could be a good option. I think it will have its place in the energy mix but not a final answer.

    doris5000
    Full Member

    AIUI, there are also questions of just how many EVs the grid can take, at least in the short/medium term.

    Can’t remember the numbers, but I recall reading that the grid in it’s current form certainly wouldn’t be able to handle all the cars in the UK suddenly switching to EV overnight. Obviously that wouldn’t happen, but AIUI, past a certain point the we don’t really know what the transition would look like, and hydrogen may also have a role to play there.

    wbo
    Free Member

    It might be easier to store but it’s a lot harder to distribute, and really infrastructure heavy.  A hydrogen refuelling station is a lot more technology intensive than a petrol station, and you don’t go far between charges as it’s not very energy dense.  Currently they contain tanks of liquified hydrogen, regas a volume back to compessed gas then fuel the car from that limited volume. It isn’t straightforward at all-

    I don’t know any oil companies seriously investigating it .  You cannot use existing networks I believe without dropping the internal pressure significantl, so you have a capacity limit, and that means any ‘hydrogen gas stations’ are going to need to repressurise low pressure gas at the station

    At least fuel cells to generate elec work, when I see car manufacturers playing with hydrogen combustion engines you know they’re dredging the ideas barrel

    Aidy
    Free Member

    Is there a push for hydrogen cars? I’ve not heard much about them for ages.

    I’ve often thought that it’d make sense to have battery powered cars for city/school run cars, and hydrogen for longer trips/transporting more things/motorway runs.

    mc
    Free Member

    Main benefit of Hydrogen, is you can create it whenever there is a surplus of electricity, refuelling is far quicker, and storage is far less limited than what you can currently do with excess electricity.

    Even if somebody develops the ideal battery, the electricity grid is never going to be able to support fast recharging of more than a relatively few vehicles in each area.

    Drac
    Full Member

    Is there a push for hydrogen cars? I’ve not heard much about them for ages.

    Very little.

    It’s not a conspiracy it’s simply business

    Yeah that’s the similar part. “Electric cars are available now but big energy companies ans governments pay them not to release them.”

    reluctantlondoner
    Full Member

    Green hydrogen is a good solution – hydrogen is more energy dense than petroleum etc, so it makes a lot of sense to use it. The challenge is that most people’s knowledge and assumptions around hydrogen are still anchored around the Hindenburg.

    The UK govt is actively trying to thwart hydrogen (look at the subsidy scheme, and the procurement regime for hydrogen on infrastructure projects) for reasons that are not clear, but doubtless nefarious.

    The EU is getting its act together and will see a huge ramp up in the coming decade.

    But for the foreseeable, most of the hydrogen will be best served in industrial settings. It makes most sense there.

    slowoldman
    Full Member

    I don’t see much difference between using hydrogen or LPG as a fuel in terms of production, distribution, use in the vehicle.

    But for the foreseeable, most of the hydrogen will be best served in industrial settings. It makes most sense there.

    As in Harry’s Garage from a couple of years ago with JCB. With development I think it’s perfectly feasible that hydrogen could become an option for small vehicles too. The “Hydrogen Economy” is something I was reading about as a schoolboy more than half a century ago. It’s time we made some serious progress.

    Drac
    Full Member

    The UK govt is actively trying to thwart hydrogen

    Hold on one the Tory Party donors is developing it so that can’t be right.

    reluctantlondoner
    Full Member

    Hold on one the Tory Party donors is developing it so that can’t be right.

    Yeah, it’s a puzzler. The HAR scheme, supposed to stiumlate demand for hydrogen has actually served to drive up the per kg cost, doing the opposite… willful incompetence? Favouring of incumbent energy companies?

    whatgoesup
    Full Member

    Hydrogen for passenger cars is not a good plan – overall efficiency is 3 to 4 times worse than batteries, so assuming sources will ultimately be mostly renewable or nuclear that’s a massive waste. Plus all the infrastructure, storage, transport etc.

    It’s also aiming to solve a problem that doesn’t exist – charging speed. When most people charge at 7kW home or at destinations then only “top ups” are needed for long journeys, which are generally very quick and only needed on long journeys where you need a break anyway.

    It has some value for kit that has to operate 24/7 or beyond reasonable battery capacity – JCB diggers on a site for example, or maybe long distance trucks.

    A lot of people seem to be clinging on to it as it’s “familiar” and similar to conventional fuels – i.e. you buy and use it like petrol/diesel – basically luddite tendencies as there is no actual benefit to this for passenger car use if you look at it objectively.

    Daffy
    Full Member

    Hydrogen is NOT easy to store.  As a gas it’s easier than impossible, but as a liquid, it’s hard to move, difficult to fill, must be kept at -253 or below AT ALL TIMES, and leaks through almost everything. You also lose a lot of it when filling tanks as you have to vent a lot to the outside air or you get other…problems.

    dmorts
    Full Member

    Main benefit of Hydrogen, is you can create it whenever there is a surplus of electricity

    Can it be made anywhere? E.g. in a refuelling station itself. That would negate the need for a distribution network

    Aidy
    Free Member

    Hydrogen for passenger cars is not a good plan – overall efficiency is 3 to 4 times worse than batteries

    In terms of energy conversion?

    I’d be interested in how it works out in system terms, as presumably you could build much smaller/lighter hydrogen cars, and I’d guess there was a greater cost for battery renewal.

    Fat-boy-fat
    Full Member

    Hydrogen is more energy dense than petroleum? Really?

    Aidy
    Free Member

    Hydrogen is more energy dense than petroleum? Really?

    … yes? By… lots.

    iainc
    Full Member

    i.e. you buy and use it like petrol/diesel – basically luddite tendencies

    ….this. I’ve just plugged my EV in, at home, with 62% battery. Yes it still has 200 odd miles range, but I have got into the habit of charging when it gets into the low to mid 60% area, regular small top ups and will cost a couple of quid during the night.

    Aidy
    Free Member

    A lot of people seem to be clinging on to it as it’s “familiar” and similar to conventional fuels – i.e. you buy and use it like petrol/diesel – basically luddite tendencies

    I don’t know that that’s fair. A lot of people don’t have the facility of charging at home, or at their destination. Charging time is a real problem for some people.

    dmorts
    Full Member

    A lot of people don’t have the facility of charging at home, or at their destination. Charging time is a real problem for some people.

    Surely it’s simpler to solve those vs overcoming the issues with hydrogen?

    Aidy
    Free Member

    Surely it’s simpler to solve those vs overcoming the issues with hydrogen?

    Why can’t you do both?

    I don’t think it’s realistic to solve charging in all locations, short of fully autonomous cars that go and charge themselves up.

    But mostly, I objected to calling people luddites for not being middle class enough to have a house with a driveway.

    dmorts
    Full Member

    Why can’t you do both?

    There is no reason. I meant more in attempting both that EVs are more likely to succeed because perhaps the issues are simplier.

    Just been looking at thedriven.io it seems hydrogen is here already, well there, in Australia. Toyota pushing hydrogen because EVs are impractical for Aussies

    molgrips
    Free Member

    I don’t see much difference between using hydrogen or LPG as a fuel in terms of production, distribution, use in the vehicle.

    The differences are there. For a start you can liquify LPG easily which means you can transport it as a liquid and move a lot of it around easily. Hydrogen is very difficult to liquify and crucially it takes a huge amount of energy which you don’t get back. Same for compressing it.

    It has niche applications but it’s not suitable for mass car usage. You’d need something like three or four times more renewable generating capacity than if you just put the energy directly in batteries.

    EVs are flying out of factories right now, and Charing stations are going up everywhere. Electricity is already everywhere. EVs work right now. Hydrogen cars don’t, so why bother? You want to build a whole new industry from scratch, develop and produce loads of new tech, waste huge amounts of energy just to avoid having to stop for 30 mins every few hours on your next long drive? It’s so not worth it.

    A lot of people don’t have the facility of charging at home, or at their destination

    Kerbside charging is a muchh, much easier problem to solve. And for those few remaining cases where EVs really don’t work (rather than being slightly less convenient) we would be better off sticking with petrol, or biofuels.

    EVs are impractical for Aussies

    Why? They must have more solar potential per person than anywhere on the planet.

    Even if somebody develops the ideal battery, the electricity grid is never going to be able to support fast recharging of more than a relatively few vehicles in each area.

    Sure? Electricity usage has been falling for a while, there’s plenty of spare capacity in the grid. Yes, certain locations may need new supply but that can be done far more easily than a complete hydrogen economy. The amount of work this would entail is huge, and we wouldn’t get any benefit from it over using EVs. In fact it would be worse.

    dmorts
    Full Member

    Why?

    Toyota said it, not me.

    johnstell
    Full Member

    Hydrogen for transport is a really tricky area to navigate as it comes in a whole bunch of ‘colours’ depending on how the hydrogen is made. Grey is split from natural gas, green from water electrolysed from renewable electricity and a bunch of different shades in between those two. There are a number of things that need to be considered but the main one is The global market for hydrogen is already huge – its primary use is in the Heinz-Krebb process in fertiliser manufacturing. It’s also worth noting that hydrogen is never transported as for practical reasons it’s always made (from natural gas) at point of use as it’s a tricky molecule to contain. It also does nasty things to steel as it can work its way between the molecules of the container. So, if decarbonisation is the goal – fix the industrial processes first that can only use hydrogen by converting to green hydrogen.

    There are also a heap of reasons why we shouldn’t consider hydrogen for transportation asides from the fact that engineering wise it’s crazy to have hydrogen hanging around for longer than absolutely necessary:

    it’s energy inefficient- at least 3 times more power hungry than BEV in round trip efficiency (that means 4 times more solar panels, wind turbines and hydro installations)

    it’s easily hijacked by the fossil fuel industry and grey substituted for green
    it’s not energy dense

    it’s already in high demand for industrial processes (as previous)

    if you split it from gas it uses several times more gas to achieve the same energy (great if you’re in the gas selling business)

    on the point that EV’s are impractical for Aussies – yes, there are some charging limitations at the moment, but containerised solar charging stations can and are being deployed off grid for remote areas and the major mining companies are converting their heavy and light fleets to electric simply because you can make it on site rather than truck it in from 1000’s of kms away. I also knock out over 40,000km a year commuting in my BEV, (70% self powered too) so it’s hard to make that point.

    I guess hydrogen cars… well it’s a bit like saying we should be running coal fired steam engines. Yes, it can be done, but it’s not exactly a good use of resources…..

    whatgoesup
    Full Member

    “I’d be interested in how it works out in system terms, as presumably you could build much smaller/lighter hydrogen cars, and I’d guess ”

    You could make a hydrogen car lighter than an equivalent battery car.  Which might improve its efficiency by 10-20% maybe.   It would need to be 300-400% more efficient to compare to batteries though.

    thepurist
    Full Member

    the electricity grid is never going to be able to support fast recharging of more than a relatively few vehicles in each area.

    You might have noticed that ye olde dino juice infrastructure isn’t particularly resilient when everyone in the area suddenly wants to fill their car up at the same time. In practice that’s rarely an issue because people tend not to all want a full tank within a few hours of each other (unless there’s either a potential shortage of supply or a sudden price change). Not sure why evs should be any different in this regard?

    Drac
    Full Member
    dmorts
    Full Member

    https://www.theguardian.com/australia-news/2023/oct/29/toyota-sales-chief-says-evs-impractical-for-australian-drivers-as-tesla-retaliates-against-cynical-attack

    They love coal too much in Aus, so that’s what powers their EVs. Toyota thinks hybrids are a better fit. Plus EVs are impractical for some reason

    johnstell
    Full Member

    South Australia 80% renewables right now. I can only make apologies for our coal burning brethren in NSW,VIC and QLD

    IMG_0076

    mrhoppy
    Full Member

    The companies looking at Hydrogen production don’t think that domestic transport is a realistic/sensible use of hydrogen. There are many better uses of hydrogen within industrial settings before it becomes sensible to use in transport.

    The processing losses are way too high compared to EVs for it to be sensible. Transport is difficult as it’s hard to get good compression, at the moment viable transport range from production site is maybe 40-50 miles and that’s at best case use (and ironically using diesel fleet). Project Union is waaaay off realisation but might get a better financial position on transport.

    HGV use and heavy plant is where they see vehicle use, but having spoken to haulers they won’t go until the unit cost of cabs is either substantially lower or subsidised. Also the HGV manufacturers have a problem that  storage requirements for hydrogen mean that without legislative changes to allow greater train length and weight it will be a difficult ask as they will lose capacity.

    whatgoesup
    Full Member

    the electricity grid is never going to be able to support fast recharging of more than a relatively few vehicles in each area.

    Simple economics means that this isn’t actually such a big deal. Right now home overnight charging is in the order of 5p/kw.hr and fast charging around 65p. So most people charge at home whenever possible.

    The other thing EVs do is enable grid balancing – using excess base load energy at night (I.e. nuclear – you can’t practically “turn down” a nuclear plant overnight) and then can feed it back into the grid at peak times. This is already a thing and is becoming more mainstream.

    dmorts
    Full Member

    The other thing EVs do is enable grid balancing – using excess base load energy at night

    I had a thought. If everyone who could left their EV plugged in (but not charging), excess load be used by charging up EVs that need a top up. Perhaps provide the electricity at a reduced rate if excess needs to be offloaded.

    thisisnotaspoon
    Free Member

    Green hydrogen is a good solution – hydrogen is more energy dense than petroleum etc

    … yes? By… lots.

    Have you seen a Kilo of liquid hydrogen?

    It’s like saying candyfloss is energy dense.

    1m3 of water is a 1000kg

    1m3 of diesel is 850kg

    1m3 of hydrogen is …….. 70kg!

    There’s an advantage that fuel cells are more efficient than ICE, but then you consider diesel (or batteries) is stored in any shape tank you like, so you can have as big a tank as you (practically) like. Hydrogen you’re limited to spheres or (heavier) cylinders.

    It’s shitty to store, it’s expensive to produce, and it’s practically impossible to transport. Refineries produce loads* of it already, it’s a normal component of natural gas, so they burn it in the fired heaters** as unless you have a local market for it (i.e. on site) it’s very difficult to sell.

    *Relatively, it might make up the bulk of the fuel gas but it’s not an excesive ammount. The LP optimisation will tend to use it up as the more cheap fuel you have the more processing you can do and the more value added.

    **Which sometimes gets you carbon credits as you’re doing work but not producing CO2 🤷‍♂️

    Daffy
    Full Member

    Let’s be clear what we’re talking about here:

    Hydrogen is mass energy dense, but its volumetric energy density is poor and it’s volumetric energy density that’s important in transport applications.

    Hydrogen can be gaseous and liquid, but for transport, only the latter is truly valid.

    As a liquid it needs to be either cryogenically cooled (massive equipment weight) or stored under enormous pressure (enormous pressure vessel weight).

    As a liquid even a fraction of a degree temperature rise leads to an exponential rise is pressure.  Imagine how hard it is keeping a pipe of any length perfectly temperature/pressure balanced with a fluid moving through at a high flow rate it and a temperature gradient of almost 270deg to the outside world.

    You need a license to have over 3.5t of LH2 fuel.  You need an audit and special permission to have over 10t of LH2.

    One of our sites has over 100t of it and the safety assessment for blast damage had a boundary of 8km.

    LH2 is very, very, very complex and dangerous.  Contrast this with electric cars….

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