As hydrogen hype is ramping up again, this time very clearly due to the fossil fuel industry putting its very large, well-funded thumb on the scales of public perception and policy-making, a pair of academic papers on the climate merits of “blue” hydrogen have been published recently. The first was by Howarth and Jacobson, and found that “blue” hydrogen had full lifecycle emissions that made it a non-starter as a climate solution. The second, by a host of authors — 16 of them, which is an unusually large number for an academic paper in this field, and more in keeping with a pile-on letter with signatories — finds that “blue” hydrogen can be a good low-carbon addition to the solution set.
The Howarth, Jacobson, et al paper will be assessed in a separate article, but this pair of pieces will assess the merits of the hyper-authored paper favoring “blue” hydrogen, On the climate impacts of blue hydrogen production, in the journal ChemRxiv. Note that this journal is in the same vein as other journals appearing at present, in that it publishes non-peer reviewed material, a very acceptable practice for important fields with long peer-review cycles but one that comes with a proviso.
As such, this article is an assessment of something that is very early in the review cycle, and some comments may become stale as the paper moves through to final publication. As a non-peer reviewed early publication journal, it doesn’t have an impact factor. By comparison, the Howarth Jacobson paper is peer-reviewed and published in Wiley’s open access journal Energy Science & Engineering, which has an impact factor of 4.07. This is not in any way dismiss the paper, but to acknowledge that it is somewhat less reliable by this measure at this time. I refer to papers in similar early publication journals regularly, most notably Cornell’s arXiv on machine learning, where peer review cycles can take two years.
The paper appears to have been in the works for a while with a subset of the authors, then the Howarth and Jacobson paper was published, and this paper was rushed to early publication in reaction, presumably with the addition of authors who wanted to make their disagreement with Jacobson known as well. This is reminiscent of the 20 author critique of Jacobson et al’s 2015 published study on 100% renewables by 2050 for the USA, a critique I found without particular merit, but in this case the publication is parallel to Jacobson’s, not directly critiquing it. My observation at the time was that everyone was agreeing that up to 80% was fully achievable with renewables, but that the last 20% would be too hard or expensive. My further observation is that last 20% is now often the last 10% according to many. I suspect Jacobson will be proven right, and further that his vision is by far the fastest and cheapest one to get electricity decarbonized by 80% to 90%, so if other technologies prove necessary for the last bit, they can wait.
That the authors are reacting to the Howarth-Jacobson paper is clear from the abstract by the way, where they say “However, recent research raises questions about the effective climate impacts of blue hydrogen from a life cycle perspective.” This is not to denigrate the authors. Like the authors of the previous critique, they have a different belief about what will be necessary to decarbonize the world, and so this is, in my opinion, something of a tempest in a teapot. Except that it isn’t. The credibility of “blue” hydrogen is essential for the fossil fuel industry to maintain its current level of policy and opinion pressure for adoption of fossil-fuel sourced hydrogen in a much larger way than any current use of the molecule.
And so, to the contents of the paper. The approach to this will be to quote key elements from the paper and respond to them.
“Hydrogen is foreseen to be an important energy vector in (and after) the transition to net-zero Greenhouse Gas (GHG) emission economies.”
This is an overstatement at best. Hydrogen as an energy vector is being promoted heavily by the fossil fuel industry, but fails multiple tests associated with economics, efficiency and effectiveness after decades of attempts. Hydrogen will be required as a chemical feedstock in industry, but is unlikely to be widely used in transportation, storage or heating. There are much better alternatives for the vast majority of use cases.
For those who missed it, I recently published a three part series with a contrarian but I think more accurate perspective on the future of hydrogen demand, one which saw global hydrogen demand falling, not rising. This is version 1.0 and intended to provide the basis for a fuller discussion. And to be clear, it’s a singular non-academic analyst’s perspective and in no way peer reviewed or intended to be peer reviewed, much like Liebreich’s excellent and useful hydrogen ladder. There are large error bars and it’s an opinion, not a prediction. But it is an opinion based on what is necessary across multiple domains for us to actually take action on climate, the laws of thermodynamics and basic economics. My perspective that hydrogen demand will be falling is a large part of the reason I don’t think that “blue” hydrogen is even necessary. Perpetuating and expensively remediating the significant negative externalities of the fossil fuel industry isn’t required to nearly the degree that the fossil fuel industry is trying to convince people it is.
If an updated version of the paper is produced that the authors might make this a more accurate statement, but note that it is not the direct point of the paper. It is, however, indicative of their assumptions, something which becomes clearer and clearer through the paper.
“The reductions in carbon dioxide equivalent (CO2-eq.) emissions per unit of hydrogen production were in the order of 50-85% when compared to standard NG-based hydrogen production without CCS”
There are two concerns with it. The first is that the goal cannot be 50% or even 85%. The goal is 100%. In connection with the expectation of a very large role for hydrogen in energy, 50–85% simply perpetuates the damage of climate change.
Later in the paper, the authors find that in the best cases with high monitoring and maintenance, it can exceed 90%. Further, they say that technologies that are in prototype today but not scaled could achieve 100%. It’s important to recognize that the authors make it clear that only in the best case scenarios with the absolute best practices and technology that is currently unproven will “blue” hydrogen be compatible with climate change requirements.
The second concerns CCS. Having reviewed all major CCS implementations and most proposed technologies, publishing regularly on the subject for several years, there is no way that CCS can or will scale to the magnitude of the emissions. At present, the total global CCUS market is 230 million tons of CO2 annually. 90 million tons of that is for enhanced oil recovery, and as the CO2 being ‘sequestered’ is first pumped from underground where it was already sequestered, is strongly negative for climate change. Meanwhile, the current scale of annual emissions is in the 40 billion tons range, and the total excess atmospheric CO2 is over a thousand billion tons. In order to stabilize the climate, we have to get to net zero and start drawing down the thousand billion tons.
This concludes the first half of the assessment of the “blue” hydrogen life-cycle assessment. As a reminder, this is non-peer reviewed draft apparently rushed to publication, and so comments in this article may not reflect the final published version of the paper. That said, given the assumptions and provenance, it’s unlikely to be substantially altered unless other reviewers find substantive errors in the modeling. I don’t dispute the LCA work that the authors have done, but am merely pointing out that their arguments about “blue” hydrogen’s value have little merit in the actual world we inhabit.