Viewing 40 posts - 121 through 160 (of 250 total)
  • Hydrogen Cars – something doesn’t smell right
  • chrismac
    Full Member

    With fossil fuels, what really matters is how much total CO2 is produced for the energy output at the end. Low grades of coal will be much worse than natural gas, for example. If you need to use earthmoving equipment to dig coal out of the ground, the fuel for those machines counts towards the CO2 footprint.

    But this article assumes that all electricity that goes into cars is produced using renewables and that is simply not true and won’t be for a long long time, we are still building nuclear power stations that will be operational for the next 50 + years. If they are counting the energy used to frac oil into petrol then they should include the energy to create electricity from one renewable sources for it to be a true comparison.

    molgrips
    Free Member

    we are still building nuclear power stations that will be operational for the next 50 + years.

    Which doesn’t produce carbon during generation.  Nuclear has its problems but it does help reduce CO2.

    J-R
    Full Member

    But this article assumes that all electricity that goes into cars is produced using renewables and that is simply not true

    I don’t understand your point here. Your comment is true, but in an EV vs H2 discussion it just means H2 will continue to be a highly polluting power source for the long term and so no good for CO2 reduction.

    theotherjonv
    Full Member

    it just means H2 will continue to be a highly polluting power source for the long term and so no good for CO2 reduction.

    Why? As I posted earlier, some very innovative technologies now in development for producing green H2 from cheaper / less environmentally damaging electrolysers and also potentially much cheaper green electricity to fuel the 3X need in the longer term.

    https://pubs.rsc.org/en/content/articlelanding/2022/ee/d2ee00876a

    J-R
    Full Member

    As I posted earlier, some very innovative technologies now in development for producing green H2 from cheaper / less environmentally damaging electrolysers

    No. If the elecity is not renewable then the H2 is not green. How efficient the electrolyser is compared to current electrolysers is irrelevant.

    chrismac
    Full Member

    No. If the elecity is not renewable then the H2 is not green. How efficient the electrolyser is compared to current electrolysers is irrelevant.

    If the electricity is not renewable then the EV is not green. What’s your point? Plus no one has come up with a way to make the battery green, or even recycle them once they are useless for powering a vehicle

    kelvin
    Full Member

    What’s your point?

    While renewable energy is still in reality scarce, and fossil fuels are still in use to generate electricity (which they will be for a few years yet… or potentially a decade or more if the Tories win the next election), then using H2 instead of EV vehicles means more use of fossil fuels because it requires much more electricity generation per a mile. If we ever get to the point where we have more electricity generated by renewable than we need (not impossible, but will need a change of mindset from all of us… why generate energy you can’t sell in a market driven society) then using that to power H2 cars, or home heating, might make sense. But it’s far more likely at that stage that the excess will be used in industry (including via H2), to encourage production to move to the UK (or wherever has got ahead of domestic demand with their renewable energy infrastructure first).

    johnhe
    Full Member

    My business is investing most of our profits into a variety of low carbon alternatives to our current business. So I have a fair amount of insight into the alternatives available. But I don’t claim to be an expert at all. Here is my simplistic take:

    – Batteries seem to work well for cars. (Although I honestly personally struggle to see batteries as a good long term Green solution).

    – Batteries are a really bad solution for larger vehicles and industrial machines. The weight is simply unmanageable. And the range is very limited. So for large Lorries etc, batteries are not generally viewed as a decent long term solution. So, in my own personally opinion, cars will probably remain EV, while larger vehicles will almost certain go hydrogen.

    – storing energy is a huge issue, since there are basically no green ways of doing so currently, except for hydro. (I don’t consider enormous banks of lithium batteries an acceptable green solution).

    – hydrogen is not easy to produce. But it is one of the only/best ways of storing electricity that we have found so far.

    – the greenest way to make electricity currently is wind or solar. But the big problem is that they are often unavailable when electricity is needed. Equally, they often sit idle when there is wind/sun available, because the demand is not there at that time. So in my simplistic opinion, H2 is the perfect solution to this. Use the electricity from wind farms, when there isn’t enough demand for electricity, to store the surplus electricity generated that can’t be consumed.

    – the H2 market isn’t really about todays world. It is really aimed at 3-5+ years down the line. Several countries in Europe are investing a lot of money in setting up distribution for H2. This is understandable since there is really no realistic, current alternative to fossil fuels for large trucks and lories (and construction equipment).

    Daffy
    Full Member

    The article uses as its starting point for fossil fuel as the point the fuel left the ground up until it hits the fuel tank of the vehicle. For electricity it claims only 6% loss for the energy hitting the solar array, or the turbine blades or coal,  gas or nuclear energy being extracted from the ground to make electricity is simply not that believable. Are they really trying to suggest that only 6% of energy is lost between gas coming out of the ground and electricity coming into the car battery, same with coal or nuclear as it doesn’t discriminate as to how the electricity is generated

    For example say 100w  of energy hits a solar panel or a wind turbine to the pint that energy gets into the car only 6w is lost? If 100w worth of cost or gas come out of the ground and used to make electricity 94w of it will go into the car?

    You’re maddeningly ill informed.

    For a car, you need to extract which requires a pumpjack or oil rig, you then need to move it which requires pumps or tankers, you then need to refine it which requires heating and chemicals, you then need to move it again which requires pumps or trucks or tankers, you then need to burn it, to get energy for movement.  ALL of the above requires input energy to get you to the point of having chemical energy which you later change into kinetic energy.  Your total input energy here is hugely relevant as you have to use a massive amount of what you refine to provide power to get you more input material to the chain.  Every step is a loss, every joule used to extract/move/refine/move/move is detracting from efficiency.

    For an EV (using solar or wind) you harness photons or wind, to turn a turbine which generates electricity, you then transmit the power (resulting in a 1-2.5% loss), you then directly use that power to charge an EV, which gives a 3-5% loss (in theory it could be as high as 25%, but in reality, it just isn’t)   You’re total input energy is irrelevant as you’re not using your output energy to generate wind or solar, it’s just there as light or kinetic energy generated by the sun and the weather, you’re not making either.

    Yes, A solar panel is around 22% efficient and an inverter is 97% efficient, but who cares – you’re not going to deplete the sun, you’re not taking that energy from elsewhere, so the efficiency is meaningless except for in terms of size.

    Check this out:  https://www.linkedin.com/pulse/how-much-energy-needed-power-combustion-car-petr-benes/

    chrismac
    Full Member

    My point is that the majority of the electricity is not produced from renewable sources. Trying to say there are virtually no losses in ev electricity is simply not true until the vast majority of electricity is produced from renewables. When it is that same clean energy can be used to create clean hydrogen which can be stored and doesn’t require batteries made from unpleasant and non recyclable materials.

    theotherjonv
    Full Member

    If the elecity is not renewable then the H2 is not green. How efficient the electrolyser is compared to current electrolysers is irrelevant.

    It’s almost like you’re ignoring the second point in the proposal; in fact you snipped that out in the way you’ve quoted my post.

    Of course it’s not green hydrogen if the electricity used to generate and compress/store it is fossil fuel based. But, IN THE LONG TERM efficiencies and scale are believed BY SOME AT LEAST to mean that electricity will become so abundant and cheap that the fact it is a 3x equation is neither here nor there. As Daffy said, we won’t run out of wind or sun.

    If we ever get to the point where we have more electricity generated by renewable than we need (not impossible, but will need a change of mindset from all of us… why generate energy you can’t sell in a market driven society) then using that to power H2 cars, or home heating, might make sense.

    Definitely not impossible, as i said PSTM are suggesting that will happen. Yes, it will require a mindset change, that we don’t turn stuff off in order to keep prices higher and instead use whatever we can create to store in other forms while we can. Maybe that’s yoghurt weaving sort of thinking, but the longer we don’t think like that, the bigger the hole we’re digging for ourselves.

    kelvin
    Full Member

    When it is that same clean energy can be used to create clean hydrogen

    One comes well before the other. Enough renewable energy to power all new cars if they are EV will be here well before enough renewable energy to power the same number of hydrogen powered cars. So we crack on with moving to new cars being EV ASAP, and develop H2 solutions for later (when renewables are at even greater scale) aimed at where batteries don’t work, be that shipping, steel production, air travel, whatever.

    J-R
    Full Member

    My point is that the majority of the electricity is not produced from renewable sources.

    That is irrelevant.   Let me explain why, it is actually quite simple.  At one end we start with a unit of electricity at a power station as our input. That might be renewable power or it might not. We have two ways of transferring that to a car’s wheels, by using an EV or by using an H2 powered car.

    For the EV the electricity travels through the power distribution system to your car’s battery, where it is stored until used in the electric motor.  Electrical transmission and electric motors are very efficient and battery storage is pretty efficient, so most of the power gets used at the car’s wheels.

    For the H2 car the electricity travels through the power distribution system to the H2 electrolyser at the petrol station, gets converted into H2, gets compressed and stored at high pressure (probably 300-600 time atmospheric pressure), gets pumped into the car storage cylinder (probably 400 times atmospheric pressure), gets converted into electricity in a fuel cell, and the electricity gets used in an electric motor.

    So the difference between the two systems is that an EV looses a bit of efficiency storing it’s electricity in a battery. But in comparison the H2 system looses a lot of efficiency electrolysing its hydrogen, by compressing hydrogen to a very high pressure, by pumping the hydrogen into the car’s cylinder and by converting the hydrogen back to electricity in a fuel cell.  All of those extra losses mean that of the electricity provided by the power station, in the H2 vehicle far less ends up turning the cars wheels than for an EV.  You need a lot more power stations to power the nations cars by H2 than by EV.  That is true whether they are renewable or fossil fuel – you need lots more of them for an H2 supply chain.

    So if we want to stop our cars using fossil fuels we have to choose between building a lot more power stations and all use EVs, or build even more more power stations and use H2 cars.

    My opinion is that since every non-CO2 power generation option (wind onshore, wind off shore, solar, nuclear) provokes fierce of resistance from one section of the population or the other we will have trouble getting enough green power for all our EVs and for our future domestic heating heat pumps, without the problem of needing even more green power for H2.

    It is true that EVs have their problems, but technology is at least as likely to engineer solutions to building recyclable and more efficient batteries than to make more efficient electrolysis and fuel cell systems. And it is also true that EVs don’t suit all use cases – it is quite possible H2 will become the least bad option for HGVs, ships and non electric trains.

    It is also quite possible in the long term we will have a method of producing as much low cost renewable electricity as we want and perhaps then H2 may be more generally used.   But I’ll be long dead before then and I think we should start saving the planet a bit sooner than than.

    chrismac
    Full Member

    I accept that part but the article was also talking about the whole process before the power station as well as the post power station. They also ignore that batteries are at best 80% efficient

    theotherjonv
    Full Member

    It is true that EVs have their problems, but technology is at least as likely to engineer solutions to building recyclable and more efficient batteries than to make more efficient electrolysis and fuel cell systems.

    At least as likely – I don’t necessarily agree, but in any case it’s not an either / or.

    It is also quite possible in the long term we will have a method of producing as much low cost renewable electricity as we want and perhaps then H2 may be more generally used.   But I’ll be long dead before then and I think we should start saving the planet a bit sooner than than.

    Me too. But as well as saving the planet we need to keep it saved, and on paper at least using infinite sources of solar or wind power to generate renewable fuel in new electrolysis plants that starts as water and ends up as water sounds like a better long term solution than other finite resources needed for batteries. And if we don’t start on that, we’ll never reach it.

    My opinion is that since every non-CO2 power generation option (wind onshore, wind off shore, solar, nuclear) provokes fierce of resistance from one section of the population or the other we will have trouble getting enough green power for all our EVs and for our future domestic heating heat pumps, without the problem of needing even more green power for H2.

    That’s not a technical problem, it’s a political one and could be solved overnight. That of course is a massive oversimplification but if legislatively we decided to approve as many wind and solar farms as we need, there’s enough wind and sun to last forever. Or at least, when the sun runs out and we can’t generate electricity from it any more then the solar system and planet is **** anyway.

    J-R
    Full Member

    BMW supporting Hydrogen

    I am sure you did not mean to use that phrase to imply BMW had switched from EVs to H2.

    BMW say in the article that “Hydrogen remains an important alternative . . we have a fleet of hydrogen cars out testing and why we’re working intensively on improving the technology further”.

    At the same time as testing a few H2 cars, just last year 2023 BMW supplied 376,183 all-electric cars.  So while they “support” H2 by keeping involved in it as an alternative , it is clear that for the foreseeable future BMW is all about the change over from ICEs to electric vehicles.

    J-R
    Full Member

    That’s not a technical problem, it’s a political one and could be solved overnight

    Really?  technically problems can usually be solved in a few years or decades by better technology.   Political problems are much more intractable.

    theotherjonv
    Full Member

    No of course not. Again you snipped out the highly relevant bit about it being a massive oversimplification, and while politicians go around in 5 year terms trying to keep the public sufficiently onside to be allowed another 5 year term then no, that choice won’t get made.

    But you could pass legislation to remove planning constraints on wind farms in a few weeks if you wanted to is what i mean.

    Daffy
    Full Member

    When it is that same clean energy can be used to create clean hydrogen which can be stored and doesn’t require batteries made from unpleasant and non recyclable materials.

    The link above explains that Lithium isn’t as dirty as fossil fuel extraction.  Also, once it’s in the eco-system, it can be reused, unlike fossil fuels.  .  Like titanium, it’s valuable enough to be worth the effort.

    Hydrogen also requires substantial energy to produce, even more to compress, vast amounts more to keep as a liquid and enormous amounts of energy to move it around.  It’s also damaging to the environment when it’s released, which happens all the time due to boil off and leakage.

    you have to store it as a liquid as the space requirements to support even a single aspect of transportation would be so vast, it would make the idea of 1000km2  of solar panels look like a good idea.

    Hydrogen will be part of the solution, but it will be made near to where it’s used.  Offshore wind, access to water, gas turbine or SOFC generators,  the very last thing you want to do is move it.

    I work in aerospace research and we’re looking at this in depth and trust me, it’s bloody difficult.  At least for power generation, it’s all on the ground so cast iron pumps (one of the only materials which works okay over long periods when subject to LH2) isn’t so much of an issue.

    Daffy
    Full Member

    Oh, and round trip efficiency for a typical lithium ion battery is 92-96%.  When you add thermal control to that, it rises by a couple of %.  Anything that moves electrons around is pretty efficient.

    Look at Airbus Zephyr.  Solar powered high altitude pseudo satellite.  Using only solar power, lithium sulphur batteries and electric motors, it can stay airborne and on station for ~90days.  All the while surveying the ground and relaying comms.  Charging and climbing through the day, descending slowly at night. You couldn’t do that with hydrogen or FF.

    Solar, wind and batteries work and they work really bloody well.  We just need to find a solution for when it’s neither sunny nor windy and that’s where hydrogen comes in.

    chrismac
    Full Member

    I work with research engineers who are spending huge amounts of time and money looking for a viable battery. Until then it’s not viable. I agree they are better than fossil fuels but that’s a long way from a sustainable answer. Batteries are still dependent on digging up rare earth minerals which by definition finite and limited

    kelvin
    Full Member

    And recyclable?

    theotherjonv
    Full Member

    And recyclable?

    Yes.

    But (and I genuinely don’t know) is there enough of the materials needed to be able to create the future battery requirements for an ever more industrialized planet. Not just the major western nations but for every car worldwide to be an EV? And is it accessible enough to be mined and refined cleanly, etc.

    molgrips
    Free Member

    Until then it’s not viable.

    For what? There’s a BEV on my drive which is more than viable, it’s significantly better than the alternatives.

    Daffy
    Full Member

    Lithium isn’t particularly rare.  Nor do you actually need a lot of it.  It’s the anode and cathode materials that’re rare earth and they’re already being reduced.

    You need on average only 8kg of Lithium for an average EV.  There’s estimated to be between 88 and 190million tonnes of lithium on land  and in the ocean.  22 million tonnes of that is easily accessible, which equates to 2.8bn typical EVs.  There are currently 1.4bn vehicles on the planet.

    We’ve already established that lithium extraction is dirty, but not as dirty as FF.  Further, we’ve established that at current energy mixes an EV will pay for its environmental footprint in two/three years.  This will then reduce emissions and this number will become even more positive over time as the grid becomes more green (we did 6months last year (4000miles) just using our solar for charging)  Finally we’ve determined that it’s easily resourceable with current reserves.  None of the above even considers recycling.

    EVs are valid right now.  Battery research is currently looking to improve upon what we have but that’s no reason at all not to start down the road.  It works.

    tjagain
    Full Member

    Its just another greenwash.  We use far to much energy moving individuals around in 2 tonne metal boxes.  EV, petrol or hydrogen makes little differnce – its all energy usage and all means more fossil fuels burnt

    Edukator
    Free Member

    the H2 market isn’t really about todays world. It is really aimed at 3-5+ years down the line

    The people on the thread who are looking at facts and stats agree that batteries are so much more efficient that much more generation would be needed to make hydrogen a viable alternative. And that hydrogen needs to be produced with renewable electricity. In Germany , BMW’s home, about 2/3 is rewable. It’s rising slowly but having the kind of surplus that would make hydrogen viable is 30-50 years away rather than 3-5.

    molgrips
    Free Member

    EV, petrol or hydrogen makes little differnce

    Whilst I agree that far too many cars drive too many miles, EV does make a significant difference to transport emissions.

    tjagain
    Full Member

    Only at the tailpipe – not overall all as every bit of electricity used in an EV ( most of the time) comes from fossil fuel burning

    Edukator
    Free Member

    Check out the EV thread, TJ, the vast majority of users charge at night when in the UK at least the majority of electrictiy is renewable. Even in Germany the electricity is only 1/3 fossil and in Germany there’s even more incentive to charge at night.

    In France there are a few very high demand days when most of the extra is from gas or coal, they’re announced on the news a few days before, I make sure I have a full battery going into those days. Living where I do I doubt my EV is charges with anything other than nuclear or renewable except when I charge on a long journey during the day.

    The Japanees cars and new R5 which allow people to use the car to power the house can do even more to reduce demand for fossil fuel electricity. You can program them to charge to say 90% over night but return 20% to teh grid before you go to work to help with peak deamnd. plug in when you return from work and the grid will take power then return it overnight to reach you 90% max charge and 70% available when you go to work.

    tjagain
    Full Member

    edukator – and unless there is a surplus of renewables ( which does happen sometimes) the electricity used in EVs comes from fossil fuels as increasing fossil fuel generation is the only way to increase output

    Demand management is good – but fiddling around the edges.

    They are still hugely inefficient ways of moving folk around.  Thats the real issue.

    molgrips
    Free Member

    Only at the tailpipe – not overall all as every bit of electricity used in an EV ( most of the time) comes from fossil fuel burning

    Only when you employ creative and somewhat absurd accounting techniques trying to score a point you never will.

    Drac
    Full Member

    Its just another greenwash.  We use far to much energy moving individuals around in 2 tonne metal boxes.  EV, petrol or hydrogen makes little differnce – its all energy usage and all means more fossil fuels burnt

    Not really greenwash, yes we should be a huge push to move away from car dependency but also look for alternatives fossil fuels for vehicles.

    I work with research engineers who are spending huge amounts of time and money looking for a viable battery. Until then it’s not viable

    It’s very viable, they can be recycled but yes there is are better alternatives to provide more range, faster charging and easier production.

    tjagain
    Full Member

    Only when you employ creative and somewhat absurd accounting techniques trying to score a point you never will.

    Actually its the EV enthusiasts that do this.  You conveniently forget that making EVs is highly polluting – that much of the time the electricity comes from fossil fuel burning as renewables are maxed out and that nuclear and renewables are not zero carbon

    EVs do reduce pollution yes – but they are the wrong answer to the wrong question.  We need to stop using so much energy to move folk around.

    The green car is the one that does not exist and is not used

    theotherjonv
    Full Member

    That’s interesting Daffy, thanks. Still a bit concerning though in the timeframes we are talking….

    there are 1.4Bn cars on the planet right now and (while I agree with TJ that we should be reducing reliance on them) demand will increase overall as more countries industrialise – what is car ownership per capita in China, India, Philippines, Brazil, a lot of Africa, etc.

    Most of them are ICE (26M EV currently, I looked up) and if in a future state we remove FF for other types, that’s a lot of batteries needed to replace even the stock we have. Enough for 2.8Bn from accessible Lithium is ‘only’ two rounds of EV batteries. Of course recycling, and of course technology will improve and of course there is more to be extracted from inaccessible places – but I’m not seeing an answer to this sum that’s making me think in the long term there’s no issue. That’s just on availability, let alone how dirty extraction is, for Li or other rare earth metals.


    @TJ
    , a large part of the last couple of pages has been on whether / when we can be entirely sufficient on renewables. Ed’s graph and post says 30-50 years, with the right intent and political support that could be (a lot) sooner. Even then 30 years is ‘in my lifetime’ sort of timescales and so I consider that still medium term.  In the long term – my kids and grandkid’s timescales – then I believe that will happen and electricity will be so abundant that the equations balance.

    That’s not to say – ‘ah don’t worry about it then, we’ll find a solution eventually’ – I want my grandkids to live on a hospitable planet, not some fiery hellhole but where they can have and EV or HV that’s economical. So yes, we do need action now and that’s why I think both EV and HV continue to be worth investment and development, and why politicians need to act sooner to drive that investment and development AND to force the hand by removing obstacles.

    whatgoesup
    Full Member

    And so another thread ruined – diverted from the actual topic and a constructive discussion into pointless arguments, nit pickiness and point scoring – by the usual suspects.

    Sigh.

    Edukator
    Free Member

    https://www.rte-france.com/eco2mix

    In Summer the fossil part often drops to zero and in Winter at night the only fossil plants still running are the ones with long start up and shut down times. If I charged now I’d be using gas ( 7% of the mix, coal 1%) but the charge finished 05:00 when the only fossil was the coal plant ticking over because they couldn’t turn it off, that in statistically the coldest week of the year.

    theotherjonv
    Full Member

    In the late 1700/ early 1800’s, slavery provided all the power we needed to do the things we wanted to do. Steam engines were around, and had some uses as an alternative technology but development was slow. We’d have got there in the end but at what cost in the meantime. Some visionary folks said that something had to be done and against the odds turned a massive tide that led to slavery being abolished DESPITE the issues that was causing – because it was the right thing to do.

    That created a massive stimulus and the speed of development of engines and the industrial revolution happened (the irony that the IR is what now leads to greenhouse gases and global warming but stick with it)

    If we banned all ICE cars from 2030 or 2035, then the development of the technologies needed would speed up hugely. All the barriers to windfarms would come down. There’s a massive tide to swim against, just like Wilberforce had but there is already line of sight to the solution. We aren’t staring at a blank piece of paper thinking ‘I don’t know’ – we know, pretty much exactly what the solution looks like, we just need to colour in the sketch.

    Over simplifies, there’s a lot of hard and clever work in that but it will happen, and with the right stimulus it could happen a lot faster.

    Edukator
    Free Member

    As for alternatives to the private car, TJ,there are routes from teh suburbs into Pau which are really well served by the bus and train network and have pretty good cycle paths. I rarely see more than half a dozen utility cyclists on the cycle path coming the other way as I ride out of town in th emorning (many more joggers and dog walkers), the buses run nearly empty and there’s a continuous stream of cars I can ride faster than if I turn round. Any gtovernment that ries to change that won’t last a month.

    Macron tried a few very minor dissasive measures and it was a big diesel driving woman on social media who reacted by starting the gilets jaunes which ended with a U-turn and fuel tax reductions. You are right with what needs to be done, now you have to persuade millions to walk to the nearset public transport, wait in the cold and rain, get on when it eventually arrives late if it hasn’t been cancelled because the driver has a cold, put up with anti-socail behaviour for the time of the journey, get off, change because most journeys will need a change so you now need a second driver who doesn’t have a cold or a hangover, get coughed and sennzed on, eventually get off and then walk (God forbid) to your destination. I use public transport (maybe more than you do despite owing a car) it’s often a grim experience. The alternative: walk 10m to the garage, get into a pre-warmed EV, chose which radio sation to listen to, get wafted by the machine to the doorstep of my destination whilst breathing air that’s been through a particle filter. Y a pas photo. 🙁

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