The Cost of Electrolytic Hydrogen from Various Sources of Primary Energy.

[NNadir]

The current issue of Industrial Engineering and Chemistry Research is the "Hydrogen Economy Issue." It contains 12 papers; most issues of this journal, which I read, regularly have more than 30 to 40 papers. This I think is a good thing. The hydrogen cheers over the last half a century or so that I've been hearing them are all paeans to wasting energy.

Hydrogen on this planet is not a primary source of energy; never has been; never will be.

The fantasy that runs around is that we'll all have "renewable hydrogen" made with so called "renewable energy" but for 50 years of wild cheering, "renewable energy" remains a trivial form of energy; I sometimes doubt that all the wind and solar facilities on this planet could run all the servers and computers dedicated to saying how great it is.

There are many reasons besides the thermodynamic losses that consumer hydrogen is a bad idea; the material issue of hydrogen embrittlement in materials science is just one example. The ridiculously low viscosity is another, as is the ridiculously low critical temperature.

Almost all of the world's hydrogen today, as his been the case for well over a century, is made by the steam reforming of dangerous fossil fuels. Electrolytic hydrogen has risen in recent years to about 4% of the world's hydrogen, but it's still a minor contributor and the hysteresis associated with shut down and restart of electrolytic cells means that it is particularly a bad idea to shut it down when the sun goes down and/or the wind isn't blowing.

Nevertheless the fantasy never goes away, does it?

The opening article of the current 12 paper issue of Industrial Engineering and Chemistry Research, Vol 61, Iss 18 is this one:

The Hydrogen Economy Preface Lourdes F. Vega and Sandra E. Kentish Industrial & Engineering Chemistry Research 2022 61 (18), 6065-6066.

I think it's open sourced.

First a little poetic color about defining the form of primary energy wasted to make hydrogen:

Hydrogen can be obtained from different sources, using both renewable and non-renewable resources, and this is normally indicated by a color. Thus, “green” hydrogen, the cleanest form of hydrogen in terms of greenhouse gases emissions, is produced by electrolysis of water, with renewable energy (usually solar) as the source. Hydrogen produced from fossil fuels (methane steam reforming), but with the use of carbon capture and storage (CCS) to reduce the CO2 footprint is referred to as “blue” hydrogen, while if CCS is not deployed, it becomes “gray”; hydrogen can also be “black” or “brown”, depending on the fossil fuel source (gasified black or brown coal). In this Special Issue, Moral et al. (12) reviews the literature for the recovery of hydrogen from coke oven gas, to improve the overall carbon footprint of steel production. Similarly, Osasuyi et al. (13) have examined recovering both hydrogen and sulfur from H2S, a toxic waste, via a thermochemical process.

Most countries foresee a transition from fossil fuel-based hydrogen supplies to green hydrogen as the technology develops. However, in 2020, only 2% of hydrogen produced globally was from electrolysis, with 76% produced from natural gas and 22% through coal gasification. (9) This hydrogen was primarily used in oil refining, to produce ammonia as a fertilizer ingredient, or for methanol production, (9) rather than as an energy carrier.

Now the cost:

Cost is another critical factor. Hydrogen can currently be produced from coal or gas with CCS for between USD $1.16 and $2.27 per kg, whereas the price for green hydrogen is between $5 and $6 per kg. (9) These costs convert to at least $8.33 per GJ for gray hydrogen and $41.66 per GJ for green hydrogen (120 MJ/kg3), when compared to a value of approxiamtely USD $5 per GJ for natural gas in the United States. (18) In this Special Issue, Wang et al. (19) aim to reduce the cost of electrolysis through improvements to the electrode catalysts. Regardless of the production route, hydrogen also consumes significant volumes of water (∼9 L per kg of hydrogen) when produced by electrolysis, (3) which can increase its environmental footprint and compete with other water demands, such as for agriculture and food production.

There you have it folks. So called "green" hydrogen is about 800% more expensive than dangerous natural gas, which should not be surprising since overall on this planet, hydrogen is made by burning dangerous natural gas.

I know we all like to play pretend, and not hear what we don't want to hear, but reality bites.

I have hopes for thermochemical hydrogen as a captive intermediate, but no, that's not going to happen by trashing thousands of square miles with mirrors to make in flight bird fryers while playing Archimedes at Syracuse. It can only be done with reliable and sustainable energy and solar thermal ain't it.

Have a nice evening.

[TheRealNorth]

1. Who's been talking recently about hydrogen as a fuel?

Or are we pretending that the green energy folks are clamoring for hydrogen? This seems like a strawmen-type rant.

Good night and good luck.

[NNadir]

2. We have regular commentary here on the subject of "green hydrogen."

If one reads enough, one can see lots and lots and lots of so called "green energy" folks clamoring for hydrogen. It's somewhat less prominent than it used to be, since the new thermodynamic nightmare is batteries.

If one pays attention, one can hear vast amounts of rhetoric thrown around about "energy storage."

In fact, it is discussed in the article from the primary scientific literature cited, using exactly that language.

The term "strawman" is very used widely, but very sloppily, often by poorly informed people. It doesn't mean shit.

Have a nice evening.

[ThoughtCriminal]

3. Based on last year's prices

I was trying to track down the source of the paper's cost estimate of $5-$6 per kg for green hydrogen. Unfortunately, it seems the authors may have used the wrong footnote. No matter, when your funding is from the UAE, rigorous proofreading might not be that important, and the figures are actually accurate based on the CURRENT cost of hydrogen production from renewables. But not for all locations - in some places the cost is well below that.

The key thing is that the cost of green hydrogen will almost certainly decrease over the next ten years while cost of fossil fuels will certainly increase. Also, the cost of fossil fuels does not include the environmental and geopolitical costs that are passed on to everybody at no (or little) cost to the industries that profit from it.

The bit about the hydrogen production leading to water shortages is questionable since when hydrogen is burned is produces clean water which could be reclaimed. In fact you can use the process to convert sea water into pure potable H2O.

I am not convinced that hydrogen is going to be an energy storage solution in every situation, but it is far more promising than this paper suggests.

[NNadir]

4. We've already bet the planetary atmosphere on predictions of what will happen ten years from now.

I actually have been hearing about a hydrogen economy for half a century, and for much of the 2000's and 2010's mocked Amory Lovins' prediction that "hydrogen hypercars will be in showrooms by 2004."

The paper reports data, not supposition bordering on wishful thinking. It is, in fact, in an issue of a prominent scientific journal which has oddly been dedicated to a putative "hydrogen economy," which, as I point out frequently, since hydrogen is not a primary source of energy, although people fall over themselves pretending it is, an energy wasting economy. The caveat is that at very high temperatures, hydrogen can be produced by increasing the exergy obtained from a system of heat networks, but that's not here and now in 2022.

Here is the result of all the talk of a "hydrogen economy" to which I've been listening for about half a century:

May 12: 421.87 ppm
May 11: 421.71 ppm
May 10: 421.13 ppm
May 09: 419.36 ppm
May 08: 419.82 ppm
Last Updated: May 13, 2022

Recent Daily Average Mauna Loa CO2

When I was a boy these concentrations were about 100 ppm lower. This happened in my lifetime, people talking about a hydrogen economy all throughout it.