The fourth big green energy technology
I really appreciate your optimism. It’s a rare commodity these days. Unfortunately, it doesn’t seem as contagious as cynicism and outrage. Thanks for the post.
Genuinely exciting developments! When it comes to energy sources, especially clean ones, I say the more the merrier. Hopefully we’ll get nuclear in on this hot green on green action, and kick clean electrolysis in overdrive.
PS - We’ll see if I regret using my excess solar energy for anything other than green electrolysis. ;-)
Conversion energy efficiency of electrolysis for hydrogen is about 80%. Hydrogen liquefies at a far lower temperature than any other element, close to absolute zero, so liquifaction for liquid storage is not an option. Energy density in the gaseous state is less than that of hydrocarbon gases.
As a footnote, the production of hydrogen by electrolyis also produces oxygen as a byproduct, so if it does catch on, LOX prices will be dirt cheap. A small, but nice, bonus for the economy.
Thanks for writing this. If we can make green hydrogren economical, then it opens a lot of possibilities.
Assuming we can produce it cheaply, the main downside of hydrogen is that it's a gas (and not easily liquefied), which makes it hard to store and transport. One solution is to convert hydrogen into ammonia, which is comparable to propane in terms of how easy it is to liquefy and hence store/transport.
I wonder if we will see ammonia used as a fuel for transportation. There are already ammonia-powered tractors. These are convenient because farmers already have ammonia available for use as a fertilizer.
Battery-powered cars are convenient because we have an electricity distribution system. But if ammonia were available at every gas station, then this advantage may disappear.
Looking around for mfg companies for electrolyzers I ran across this blog:
which seems to agree about exponential growth but not about why.
We should not dismiss the enormous potential in using hydrogen for long distance air travel. The fuel consumption of an aircraft is fundamentally a function of its weight and hydrogen is as good as it gets for energy weight density. Infrastructure is only needed at relatively few locations (airports) and cook-off shouldn't matter as much as for say ships.
Thanks, this is great overview and since David Roberts has blocked me appreciate update.
In long run, how does hydrogen storage on it's tearning curve for electrolysis and storage compare to "overbuilding" solar with its very impressive learning curve?
That is, it keeps happening where it's so often cheaper to build more solar than needed for most solar abundant times of day/year, to have enough solar at low solar times, or just cheaper to build solar panels facing different directions so they are more efficient in low solar times, sacrificing production in high solar times but that sacrifice "curtailment" still nets out to low cost electricity over whole year.
Seems it will depend on location (north vs south) and in long-term, what the delta of the hydrogen and solar learning curves are
We’re seeing these learning curves more and more. I wonder if they should be accompanied by rate of deployment plots since that is their fundamental input? A big question: Is rate of deployment constrained by factors other than cost. Jewell, Cherp et al take a hard look at this https://twitter.com/acherp/status/1417373405960155149
Storage is the big question. Right now it appears salt dome caverns is the only viable <10$/kWh approach, and they are geographically limited. If we are really lucky and they work well we may get that to ~$1/kWh.
Old NG wells are not suitable, unlike for storing NG (contamination, permeability), and there is a hard floor of 4x the cost of storing NG due to volumetric differences, and NG storage is VERY mature.
LH2 is much harder to make, store, and transport than LNG, so we should not expect that to be significant.
H2 is very necessary for decarbonization, but we should not expect a significant trade in H2. Instead the users will need to be near where it is made and stored. This is bad news for Germany’s industrial base…
In genes rap it is better to store H2 for user, rather than power. That should be an extreme backup, instead we can divert the power to make it for direct power most of the time when needed if the electrolysers are cheap enough.
In the late 90s, the US national HS policy debate resolution one year was that the US should invest in renewable energy. My team's affirmative case was about hydrogen batteries. At that point, most of what we had to back it up was some basic R&D and conjecture about the cleanliness of the technology.
If only I'd had the capital as a 15-year-old to put my money where my mouth was.
Excellent stuff. Harking back to one of our other (free) postings, is there a learning curve for liberal democracy?
Great read, thanks.
Think the issue with this is:
1. It's only truly "green" if it uses surplus green electricity. In most places, we're decades away from being in that position (just look at Germany today - how much they've spent on renewable energy to date and how far they are from having a green grid). Until we get to that point, "green" hydrogen is just displacement of emissions.
2. Utility solar isn't zero emission. The lifecycle emissions are around 50g/KWh. Once you account for the system loss of using Hydrogen (say, around 50%), that gets you to around 100g/kwh. A Tesla model 3, driving on a highway, consumes about 80kw/h per 200 miles so 4kg of CO2 per 100 miles. It's about twice as efficient as a small European ICE car. It's great, but doesn't get us to net zero (and even less so if you include the emissions linked to producing the car).
3. Would love for someone to actually do the maths on just how much land we'll need to produce enough renewable electricity to cover full electricity needs today + electrify most of the fossil fuel use cases. My understanding is that to get there would require 1/8th of the total land area of the lower 48 states.
Whilst I agree with you that hydrogen will be an important piece of the puzzle (especially in industrial use), the issues with leakage are very material, as highlighted elsewhere. I work in infrastructure and energy financing, and refitting the natural gas grid is extremely demanding. I'm also skeptical of large scale storage for this same reason; the leakage issues (due to molecular size) both make long term storage more difficult *and* make transport to where it's needed harder.
A note of caution on batteries: the learning curve is happening on the non-commodity part of the cost. However, over time, the commodity cost is becoming an ever larger part of the battery cost, as anodes/cathodes/etc get cheaper and more efficient. Many people are working on non lithium/cobalt batteries, and I wish them the best of luck, but if we don't have a breakthrough there, using the current commodity structure *will* lead to a flatter learning curve (as if 90% of the battery cost is the lithium, making the tech part half as expensive only gets you a 5% savings).
Take the two together, and I think storage is going to be one of the hardest nuts to crack of the transition, and will incentivise a lot of overbuild in the medium term (or continued use of natural gas plants).
There is one thing that has been missing in all these discussions. My brother tested and built hydrogen systems about forty years ago (production of hydrogen from water -believe it or not - in the Mohave Desert), hydrogen powered aircraft engines, etc.
There is a major problem with all this. Hydrogen is, I think, the smallest molecule in chemistry. And it leaks through any standard valve or pipeline connector. I have yet to hear any discussion of the future of hydrogen mention this problem or provide any information about steps taken to reduce leakage in the proposed systems.
Did you talk about conversion efficiency loss? Cost viability? Why not be techno optimist about nuclear?
Noah, I expect there would be a learning curve from nuclear as well if it got any of the attention that the myriad, mostly-failed-to-date technologies on which there are curves (praying they continue) get. There has been almost nothing significant done in nuclear for 50 years for reasons unrelated to science or technology but closely related to "green" politics (despite the fact that nuclear is more green than many such promoted approaches). So it is likely disingenuous to state it does not have a learning curve. If batteries/wind/solar/whatever were ignored to this extent, I am confident they would not either.