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The rise of green hydrogen in a global and Irish context



  • Posts: 0 [Deleted User]

    The rising gas prices caused by the Ukrainian war is making the economics of green hydrogen a lot better a lot sooner

  • Posts: 0 [Deleted User]

    A watch out for the hydrogen industry as it ramps up, leaks will cause climate issues as it is a GHG in itself

  • Registered Users Posts: 1,093 ✭✭✭gjim

    DaCor, I know you're a fan of hydrogen, but the more I learn about it the more skeptical I get.

    This is basically the opposite what happened when I started looking into other de-carbonization technologies particularly wind, solar PV and li-ion BESS. From a renewables skeptic less than a decade ago, I've become the opposite - fully evangelised with the zeal that mankind is on the brink of a revolution in energy technology bigger than that caused by the emergence of oil in the 19th century.

    I kinda shrugged when it came to hydrogen; I couldn't see a compelling argument/use for it except long-term (months and year scale) energy storage to complement variable renewable generation. Although even this wouldn't be a critical issue for years if not decades and we have massive scope for the de-carbonization of energy without requiring a solution in this area.

    But I was under the impression that hydrogen has a key and critical advantage over methane/natural gas - which is that leaks are harmless in terms of GHG effects. But it turns out that hydrogen is terrible in this regard - as bad as methane? And of course hydrogen by its physical nature is more prone to leakage.

    So why bother with hydrogen at all? We have processes whereby we can use electrolysis to produce methane from the air with almost the same efficiency as hydrogen electrolysis? We already have all the infrastructure and technology to pipe methane (natural gas) around, store huge quantities of it, ship it across oceans, turn it into electricity, heat homes with it, run vehicles, etc. All of these things can be done right now, with zero extra capital investment, and cheaply/efficiently with methane while hydrogen requires the construction of a completely new global gas infrastructure.

    I just don't get the point. I'm not a conspiracy theorist at all, but it seems more and more to me that the hydrogen hype is a way for the existing fossil fuel industry to use "green arguments" to extract rent/subsidies from governments to make up for the loss of market to renewables. It reminds me of the nuclear industry in that regard. Why does it seem that all of the biggest names in hydrogen are or were previously oil and gas extraction or support companies?

    In other news, it looks like "blue" hydrogen is also a bust and is worse than burning diesel 😳 in terms of overall GHG emissions according to this peer reviewed article - - even with 80% carbon capture.

  • Registered Users Posts: 28,765 ✭✭✭✭Wanderer78

  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,625 Mod ✭✭✭✭Capt'n Midnight

    Even at a high leakage rate it would have about half a percent of the impact of fossil fuels. And it's got a very short lifetime too.

    It atmospheric lifetime is about 2.5 years and there is a global burden of about 180 Tg in the atmosphere ... If a global hydrogen economy replaced the current fossil fuel-based energy system and exhibited a leakage rate of 1% then it would produce a climate impact of 0.6% of the current fossil fuel based system.

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  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,625 Mod ✭✭✭✭Capt'n Midnight

    "I couldn't see a compelling argument/use for it except long-term (months and year scale) energy storage to complement variable renewable generation."

    It's a grid scale storage solution that re-uses a lot of existing infrastructure.

    Medium term solar will likely hit €10/MWh in parts of the EU, maybe even here. At 40% efficiency that's €25/MWh. That's competitive with future costs of fossil fuel when you include carbon taxes. Even at twice that cost it undercuts lots of alternatives.

    And it's all mature technology. Yes there's an issue with retro fitting larger combusters to existing turbines. But you can get other turbines that will run off 100% hydrogen now. ( if you were to store hydrogen in a gas field you'd get a mix of gases coming out until the hydrogen diluted the existing gas so more time to sort out combustion and emissions will go down over time )

    It's way under the cost of proven nuclear technology. And way under the cost of "economic" small modular reactors that only exist on paper. Hundreds of small modular reactors have been used since the 1950's but they aren't remotely economic. It's half the predicted cost of an emerging unproven nuclear technology that will need 30 years to develop.

    New pumped storage has double the efficiency but higher capital costs so could also be under cut by this.

    Battery storage should be OK because it's very fast responding.

  • Registered Users Posts: 1,093 ✭✭✭gjim

    The point of DeCor's paper is that the previous estimates of hydrogen's warming effect underestimated hydrogen's potential for contributing to global warming. The paper you quote from was written in 2006 and much of the references in it are papers written in the 1990s. In contrast, the latest research is prefaced by:

    "While hydrogen-induced changes in methane and ozone in the troposphere [the lowest layer of the atmosphere] have been considered previously, we have also considered, for the first time, previously ignored changes in stratospheric [that is, in the second-lowest layer of the atmosphere] water vapour and stratospheric ozone in our calculations of hydrogen’s GWP,”"

    And the leakage numbers are much higher than 1% - you should read the paper.

    It's bad news for hydrogen - this was the the last remaining big benefit hydrogen could claim over natural gas/methane. At this stage, I can't see any rational reason for preferring hydrogen-from-water electrolysis over a methane-from-air process given both are equal in terms of life cycle net carbon. The latter can be used immediately to supplant fossil sources of methane - the former will require 10s of billions if not 100s of billions in new infrastructure, and will take decades to contribute to reducing GHG emmissions.

  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,625 Mod ✭✭✭✭Capt'n Midnight

    From DeCor's paper Whilst the benefits from equivalent CO2 emission reductions significantly outweigh the disbenefits arising from H2 leakage, they clearly demonstrate the importance of controlling H2 leakage within a hydrogen economy. and they are talking about leaks of 10% which given the explosion limits of hydrogen/air are scary. For grid level All other production, transportation, storage and uses of hydrogen would see leakages of less than 0.53%

    And those 10% leaks were based on replacing fossil fuels for heating and transport. District heating and heat pumps could displace a lot of gas and oil heating.

    Doubling the greenhouse gas effect is offset by halving the leaks.

  • Registered Users Posts: 1,093 ✭✭✭gjim

    Of course, producing green hydrogen using electrolysis and then combusting it results in less CO2 emissions than extracting fossil fuels from the depths of the earth and burning them for energy releasing the carbon into the atmosphere.

    But that's not what I was questioning. Why bother with hydrogen at all when we can use other power-to-gas processes to synthesise methane from power - this can be done without adding any (net) carbon to the atmosphere, can immediately be used to displace fossil sources of methane (natural gas) and requires NO new infrastructure?

    The answer I would have given in the past is that handling and processing natural gas/methane invariably leads to leakage into the atmosphere and methane is a potent greenhouse gas while (I had believed) that this was not the case for hydrogen. But now that it seems hydrogen is at least as bad as methane in that regard, why exactly do we need to spend 100s of billions on brand new hydrogen infrastructure when we could achieve the same GHG reduction by storing excess energy in the form of methane?

    I don't get it...

  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,625 Mod ✭✭✭✭Capt'n Midnight

    In most cases you still need to produce the hydrogen because you are adding it to something.

    Methane has one carbon carrying four hydrogens. Ammonia is one nitrogen carrying three hydrogens. Methanol is a replacement for petrol that sorta has just over three hydrogens per carbon. Other liquid fuels are near enough two hydrogens per carbon.

    Other alternatives are biofuels from algae , carbon capture from air and hydrogen from water. Heating biomass to use the volatiles as fuels and bury the char to sequester carbon in the ground is another approach.

    But yeah using hydrogen stripped from methane probably won't ever be great since you'd lose so much energy in the processing and storing of the excess carbon. And any mechanism that offset the carbon could probably be used to generate fuel directly instead.

    Germany during WII and South Africa during the sanctions show that there's lots of alternative fuels if time and effort are applied. Though using much of the annual harvest of potatoes to produce alcohol for rockets also shows that we shouldn't use food plants for fuel, quick growing algae would be a better option if was easier to separate out the fuel from them.

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  • Posts: 0 [Deleted User]

    Another article giving a little more detail on the hydrogen leakage risks.

    Important to note this is a single study so far so that's always a big caveat with these types of articles.

    If this is an issue it's good to see it being spotted now, early in the development of hydrogen infrastructure. If this comes up in more studies I'd expect regulators, planners and environmental agencies to start requiring monitoring, tracking and tracing to be implemented across the supply chain with rigorous reporting requirements.

    I'm still a big supporter of hydrogen and it has massive potential as energy storage and release (e.g. Fuel cells) but between this and the emissions from burning it, it may be be turning into a poisoned cure if its not done right.

    On a side note, has anyone seen any grid scale proposals for hydrogen usage that involve the likes of fuel cells?

  • Registered Users Posts: 13,613 ✭✭✭✭josip

    From reading the above article. If we could remove some of the atmospheric methane we would get a significant short term boost in the global warming battle. It would buy us more time to sort out the carbon emissions. If we pumped hydroxyl radicals into the (right part of) atmosphere, would it speed up the decay of methane?

  • Moderators, Science, Health & Environment Moderators Posts: 19,316 Mod ✭✭✭✭Sam Russell

    If you want to tackle methane, it should be done as close to the source as possible.

  • Registered Users Posts: 1,093 ✭✭✭gjim

    "On a side note, has anyone seen any grid scale proposals for hydrogen usage that involve the likes of fuel cells?"

    The round-trip efficiency (electrolysis to fuel cell) is quite poor - at under 40% (I believe?) - compared to any type of battery. So I guess it could theoretically be done but it'll really struggle to make the operational finances work.

    The only future for green hydrogen that makes sense to me is to displace the grey hydrogen used in industry. I'd be an enthusiastic supporter of electrolysis in this role given current production methods account for over 3% of global CO2 release. Medium sized electrolysis plants could be located on-site avoiding most of the (unsolved) difficulty and complexity involved in the storage and transport of hydrogen.

    I just can't see much of a role for it in energy given the poor round trip efficiency via fuel cells. There is talk of combusting hydrogen - either mixed into natural gas or pure hydrogen turbines but the high temperature of hydrogen combustion mean there's no getting away from huge amounts of NOx generated in the process. And once you require any sort of thermal engine, you're going to take a big efficiency hit also.

  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,625 Mod ✭✭✭✭Capt'n Midnight

    You can get 40% round trip with CCGT, or rather you will by 2028 when they sort out how using higher %'s of hydrogen, but turbines are in the hundreds of MW. If use salt domes or old gas wells then it's storage on a completely different scale to batteries, with a fraction of the capital costs. Roughly 80% conversion of electricity to hydrogen and 60% conversion in CCGT. Fuel cells are 60% at scale so (maybe 80%)

    Using it to displace methane in the gas grid is an easier way to use the stuff in the meantime. NOx isn't an issue as it's part of the redesign of the existing turbine models. Another solution would be to store the oxygen from hydrolysis too.

    Scottishpower are building a 100MW hydrogen plant in Felixstowe for £150 as it's reached price parity with diesel for usage in the port.

  • Posts: 0 [Deleted User]

    A planning application lodged by BnM for their Mount Lucas site.

    A pilot hydrogen electrolysis plant.

    On eplanning, 22379 Offaly CoCo

  • Registered Users Posts: 1,093 ✭✭✭gjim

    You're downplaying the NOx issue. Without huge negative implications for human health - hydrogen cannot be used to displace domestic NG consumption. There is absolutely no way you can propose people cook or heat their homes using a 20% hydrogen mix if the generated NOx levels go up 10 fold - unless you want to face decades of litigation. Thus, unless you're going to duplicate the gas grid infrastructure (providing separate grids for pure NG and the methane/hydrogen mix), this "20% mix" idea is fantasy.

  • Posts: 0 [Deleted User]

    Yeah nox makes hydrogen combustion a non-runner for several reasons not least of which nox is one of the big 3 GHG's which we have to reduce.

    There is also no CCS type tech for capturing nox at scale that is remotely effective. Maybe that will change.

    Hydrogen is touted as the great storage hope and I truly hope that we can use it safely and without emissions but I cant see how combustion can be any part of the equation.

  • Registered Users Posts: 9,249 ✭✭✭cgcsb

    Just seen BNM mountlucas windfarm looking to develop hydrogen generation and storage. Surely they also then have to burn it for electricity at times of low wind? Or what are they storing it for? Could be a great solution to give more balance to wind production.

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  • Registered Users Posts: 27 WillYizCopOn

    I've been researching how green energy is made. The one thing I can't figure out is where the water goes after electrolysis. The oxygen is released into the air and the hydrogen is harvested. What's left? Is the water all gone after this process? If there is water left over, then I would assume it would be heated and this wouldn't be good to put back into streams/wells etc. Anybody out there have the answers?

  • Posts: 0 [Deleted User]

    The water is split into its H and O components, Hydrogen and Oxygen. There is no water after

  • Registered Users Posts: 19,646 ✭✭✭✭cnocbui

    There is no water left, but the water has to be fresh, which is going to make generating hydrogen from solar in the Sahara or Australian outback a bit tricky - not to mention that you can't turn your electrolysers on and off at will, they have to be run constantly, so how are you going to manage that with solar, at night? Same with this idea you use excess wind - when the wind drops, you then need to feed the electrolysers with energy from burning coal or gas. How stupid is that?

    The whole nonsense of using 'free' excess wind or solar whenever there is some, has knobs on it. And it's not free - you have to pay the windfarm investers for it and lose piles of money because the green hydrogen round trip efficiency is low. Pay the investors a million and you'll only get back 400,000 worth of energy if your system is perfect, lower efficiencies are more likely and could be as low as 18% If we take the median as 33%, then spend a Euro and get 33c back.

    I need to look into buying shares in a wind farm, there are stupid sheep just begging to be fleeced.

  • Registered Users Posts: 3,062 ✭✭✭hans aus dtschl

    "Electrolysers need to be run constantly" is this based on something in the Australian energy market, or is there some specific technical reason that an electrolyser would need to be run constantly?

  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,625 Mod ✭✭✭✭Capt'n Midnight

    The energy required to split water into hydrogen and oxygen is a lot more than needed for distillation or desalination.

    Besides electrolysis of salt water still produces hydrogen. And chlorine and sodium hydroxide for which there's industrial demand over of 60 million tonnes each a year.

    Or you could use power lines to transport the electricity. China already uses 3,000Km lines, 100's of Km longer than you need to get to the nearest ocean from anywhere on the planet.

    Which types of electrolysers need to be run constantly ? Alkaline , Acid, Proton Exchange Membrane, Solid Oxide or other ?

    It's not nuclear power. The price doesn't have to b fixed (in either senses). You could store excess renewables when they are cheap such when output exceeds demand and the opportunity to harvest energy would otherwise be wasted.