Hydrogen or Litium, is that the question ?

My friend Ernesto Ciorra, CO innovation and sustainability officer at ENEL (90th largest company in the world by revenue, with €140 billion in 2022 and the second largest power company in the world by revenue after the State Grid Corporation of China) published a post on linkedin on the fact that batteries+electric lines are preferable to hydrogen because energy conversion efficiency to/from hydrogen is very low. (an undoubtable fact of physics)

This argument, though, does not buy me fully in.

My point is: in a world where energy production in some moments has a 0 (or negative) cost, who cares if we waste a lot of it in the conversion ?

Perhaps we should consider the cost/impact of transporting energy after it has been converted to some transferable mode, to the point where it is reconverted and used.

I mean, if we already have in place gas pipes, why not using those to dispatch energy instead of building new electric lines ?

For cars, why not using FCEV hydrogen fuel cells, so that we could refill in few minutes ? the dependence on platinum (which incidence, BTW, is being reduced) poses less strategic issues than rare earths used in batteries.

Am I missing something ?

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8 thoughts on “Hydrogen or Litium, is that the question ?”

  1. Per la trazione ormai è assodato da un tot che l’idrogeno è semplicemente morto:

    produrre elettricità –> idrogeno –> elettricità (e comunque devi usare batterie, perché le fuel cell non le moduli velocemente, anzi) –> motore
    produrre elettricità –> batterie –> elettricità –> motore.

    Il tutto senza contare gli oneri di trasporto e infrastruttura.

    Resta da vedere se sarà più conveniente per navi ed aerei, che hanno tutto un altro sistema e altre possibilità.

    Personalmente ho la sensazione che nel prossimo futuro, a meno di scoperte eclatanti, vedremo un ritorno delle “Extended Range”, auto elettriche con meno batteria ma un motore termico aggiuntivo ad alta efficienza per la ricarica in marcia (ci sono dei motori in grado di avere oltre il 50% di efficienza contro il 30-35% di quelli normali, estremamente leggeri — niente albero a gomito, camme, cambio — e piccoli).

    Poi purtroppo le regole non le fanno i tecnici, ma i markettari… 😠

    1. Stefano Quintarelli

      il mio punto e’ che gli oneri di trasporto sono gli unici da considerare, perche’ la produzione non costa e puoi sprecarne quanta vuoi.
      se c’è già un gasdotto, perchè non usarlo per il H2 ?

  2. @quinta you are missing some points:
    1) you cannot transport 100% hydrogen through pipes, you need to blend it with natural gas and it’s difficult to go above 7% in volume. You also have to transport a higher volume of gas per unit energy
    2) hydrogen has to be compressed/liquefied, and transported, losing other energy
    3) to convert back hydrogen in electricity you lose another large fraction of energy due to fuel cell not-so-good efficiency (which depends on the kind of FC)

    Additionally, FCEVs OPEX is 5x-8x BEVs, making hydrogen for transportation a quite dumb idea

    1. Stefano Quintarelli

      issues 2 and 3, i.e. loosing energy, is not an issue if the cost of the energy is 0.

      do you have data on the need to blend with NG and the 7% limit ? and on the vehicle opex ?

    2. MrBrown gave a very detailed answer.
      To keep it simple: hydrogen atoms are tiny and they diffuse into grain boundaries of metals, embrittling and cracking the pipes, the welded joints, and so on. 7% is just a value stating the order of magnitude. could be 5% or 10%, even above, but I wouldn’t recommend.

      5-8x opex is mainly due to energy costs. A FCEV in practice is a BEV (with super small batteries) where electrical energy produced directly from H2 through a PEM-FC, whose efficiency is ˜50%, doubling the energy consumed by an equivalent BEV. Add to that the maintenance costs of a PEM, the lower overall efficiency of hydrogen production compared to direct electrification and you get that range.

      in addition to MrBrown suggestions I’d put on the list Michael Liebreich’s podcast CleaningUp and Shayle Kann’s podcast Catalyst

  3. Yes, you might have missed something.
    First, safety: hydrogen is an extremely flammabe gas, it easily forms explosive mixtures with air, it burns without a visible flame, hydrogen flame is unstable. You just don’t want to deal with hydrogen safety issues.
    Second, logistics: in gas form it leaks from flanges (you must weld everything), it causes corrosion, it requires special (expensive) metallurgy. Stating that natural gas infrastructure is fully compatible with hydrogen (pure or rich mixtures of H2 and natural gas) is not completely true. In the liquid form, H2 liquifues (or boils) at – 252 °C. Methane, for comparison liquifies/boils at – 161°C. 90°C is a big difference: LNG and liquid H2 are as different as ice and steam. LNG tankers are not suitable for liquid H2: consider the “boil-off” issue (burning the H2 boil-off is a further issue) and the liquid “heel” left for the return trip.
    Third, efficiency/yield: we consider the gas price “expensive” when TTF is at 40 €/MWh. Producing H2 at that cost, with te best electrolyzer yield at 70%, means an electricity price of less than 30 €/MWh (optimistic). If the average electricity price were so cheap, the world would already be a better place, and we would have solved all our problems, without hydrogen. Otherwise, that is the real world, you can only produce cheap hydrogen during the cheap electricity hours, which limits the productivity, burdens the capex/amortization, and confines the H2 use as “chemical” energy storage. If you imagine a more extensive use of H2 as a substitute for fossil fuels, low yields directly impact the size of the renewable energy installations. Like 20% net H2 energy yield, means installing 5x the area of a wind farm or a pv field: it’s clearly unsustainable, even without considering the costs, that would mean huge extensions of land and sea that should become private property of utility companies for decades (I would call that feudalism 2.0).
    Fourth, “moral”: the fact that energy might be cheap doesn’t mean that you’re free to waste it. Just like food, just like water… in fact the energy “cost” is never low, I think you were thinking of the “price”, the market price.
    Fifth, options: I think you are considering H2 as a non-GHG energy “solution”. According to WEF you need 48-50 kWh of energy to make 1 kg of H2, which is “equivalent” (on an energy basis, compared to NG) to “avoiding” 7 kg of CO2. That is around 7 kWh of renewable electricity to “avoid” 1 kg of CO2. Believe, for a second, that you really avoid GHG emissions, because you are shutting down a fossil power plant (not true). You might have other options to spend those renewable kWh to generate a positive impact on the planet. For example, some direct air capture of CO2 (currently not developed at industrial scale), “promise” to “remove” CO2 using just 2.4 kWh of (renewable) energy. As a matter of fact, Removal is tangible, because you can weight, and id successful you can measure decresing ppm of CO2 from the atmosphere; Avoidance is intangible and is subject to “certification schemes”, greenwashing, etc. I’m not promoting DAC, as an alternative to green H2 (there are fierce debates on both technologies). I just want to highlight that, in an ideal scenario where we might have abundance of renewable energy at low price, there’s an allocation problem to be solved, and H2 may not be the preferable technology.

    1. Stefano Quintarelli

      Thank you
      do you have some reading ssuggestions ?
      clearly you have very solid arguments, thank you.
      the only point I don’t buy is “moral”: every era is characterized by the resource you waste. Once production has a negligible cost, it is perfectly fine to waste it, what are the other alternatives ? At home we are now carbon negative with our heating/water/transportation needs. (we’re not for holidays, work trips). We were extremely saving conscious, now we’are not. IMHO food and water comparison is not correct, both are very limited resources with significant energy/work associated to their production/delivery

    2. Regarding safety, my first reference is any safety datasheet, available from hydrgen manufacturers and users. Safety literature on hydrogen is well known in all the industries using this substance in their processes, for example oil&gas, chemical, petrochemical, steel and also aerospace. Hydrogen safety is also addressed in university courses and textbooks.
      You may find lots of references for example on Science Direct (sciencedirect.com) : “hydrogen explosions”. In general the flammability limits of H2 in air are very wide: from 4% to 75%. Hydrogen is subject to safety regulations, such as EU ATEX Directive. All these issues are very well known to specialists and technologists. Technology and engineering companies define specific requirements and standards for hydrogen in their piping classes (such as materials, fittings, etc.). Piping classes are generally confidential.
      Plenty of publications are available on the modeling of boil-off in LNG tankers, as this represents a relevant issue regarding the current world gas market. Studies on hydrogen, correlated to this topic, are also vailable. Sciencedirect publications are a good source. For example Al-Breiki and Bicer, Fuel Volume 350, 15 October 2023, 128779.
      On electrolyzers technologies and efficiencies you can refer to the same source of publications. There are several competing technologies, at different levels of readiness. Some are very promising. You can refer, for example to NREL open publications (https://www.nrel.gov/hydrogen/renewable-electrolysis.html). It is, in general, difficult to find energy yields (energy:energy, that is, renewable electricity/hydrogen higher heating value) higher than 60%. Also the current EU Innovation Fund methodologies in some documents assume a 60% value. That is low, and it’s just the yield of the electrolysis process.
      Regarding the overall yield (and problems cascading on the land/sea area that would be required), a good source of studies and publications is The Northern German Living Lab (https://en.norddeutsches-reallabor.de/) In Hamburg they’re doing a great job on assessing the feasibility of wide hydrogen energy networks. I recommend you a couple of studies: Grüner Wasserstoff für die Energiewende Teil 1 and 2. There is shown that uses of hydrogen (including heating) are often affected by unacceptable low yileds.
      Regarding the comparison with alternative options, you may refer to World Economic Forum (https://www.weforum.org/agenda/2023/03/understand-carbon-footprint-green-hydrogen/) . I took the 2.4 kWh per CO2 removal drom Direct Air Capture from WRI ( https://www.wri.org/insights/direct-air-capture-resource-considerations-and-costs-carbon-removal)
      Finally, regarding the moral problem: yes I don’t expect you to buy that, but it’s inherent in our way of living on this planet. It’s more about your political views, your thoughts about economy and ecology. Capitalists just neglect the costs of things that have a low price. Probably we need a deeper meditation on the morality of wasting cheap resources. First of all: what is the definition of “cheap”.
      As a general reference, I personally find interesting listing to people like Jan Rosenow (especially focused on the problems of heating: hydrogen vs heat pumps) or Michael Liebreich, who condensed a lot of interesting considerations on the “Hydrogen Ladder”. For a broader view on the limits of our planet Auke Hoekstra can be a good reference.

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