Cheap, green hydrogen would be a breakthrough in clean energy • Hacker News Board

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#101

Post by ncmncm » Wed, Jun 22, 2022, 1:03 AM UTC

rich_sasha wrote: post #59

derriz wrote: post #25

I don't see hydrogen playing any role for energy storage or grid demand balancing. Even if all the technical and engineering challenges associated with storing and transporting it safely could be addressed, I just don't see how the economics of green hydrogen is supposed to work. The round-trip energy efficiency of electrolysis-fuel cell is poor - currently about 40%. The counter-argument is that such inefficiency do…

The point is that some countries have long dark winters, often with windless spells. Some are also lowland countries with little or no access to hydro. For green energy, you'd need to literally store months' worth of energy somehow, and the cost of doing that via batteries is prohibitive too. I guess the hope is that storing hydrogen, difficult and expensive that it is, could be made to be more like storing hydrocarb…

Energy will be stored, at utility scale, in many forms.

Hydrogen will be one of those forms. Ammonia, another. Batteries, in small amounts. There are myriad others.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#102

Post by ncmncm » Wed, Jun 22, 2022, 1:05 AM UTC

vkou wrote: post #31

derriz wrote: post #25

I don't see hydrogen playing any role for energy storage or grid demand balancing. Even if all the technical and engineering challenges associated with storing and transporting it safely could be addressed, I just don't see how the economics of green hydrogen is supposed to work. The round-trip energy efficiency of electrolysis-fuel cell is poor - currently about 40%. The counter-argument is that such inefficiency do…

> Since the cost of green hydrogen production is mostly cap-ex not op-ex Is it? I always thought that it was always op-ex, because you need to burn two joules of energy, in order to produce one joule of hydrogen-potential energy. Which, in a world where you can dig coal out of the ground for $30/tonne, is uneconomic.

When electricity op-ex is free, as from panels, electrolysis is too.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#103

Post by ncmncm » Wed, Jun 22, 2022, 1:06 AM UTC

Animats wrote: post #47

plutonorm wrote: post #35

Earlier quoted context omitted.

The only reason it's discussed is because the fossil fuel industry has a lot of experience and infrastructure around liquid fuels. It wants a future where there is a new liquid fuel so that it can leverage that experience and infrastructure. They are pouring huge sums into moving the academic and public conversation in the direction of hydrogen - it's like the tobacco companies all over again. Don't trust a word that…

Yes. I'm surprised to see this from Bill Gates: "Another option is to produce hydrogen using the current methods that burn fossil fuels and then capture the CO2 produced in the process before it’s released in the atmosphere. It may never be economical to capture 100 percent of the carbon released using incumbent technologies, but while we’re waiting for thousands of industrial facilities to retrofit their infrastruct…

There will be market for as much hydrogen as we can ever produce. Much of it will be bound to nitrogen, for ammonia, or to carbon, for kerosene, used directly in e.g. steel manufacture and in aircraft, and as feedstock for thousands of chemical processes.

It will undercut any sort of extractive stuff, because marginal cost is near zero. Wherever it can be used in place of one of the other things, it will be, because it will be the cheapest portable energy.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#104

Post by clouddrover » Wed, Jun 22, 2022, 1:08 AM UTC

craig1f wrote: post #2

It would. Yet there is no promising tech in this field. Hydrogen is supported only to draw support away from EVs. If hydrogen becomes inexpensive to produce, it will by by way of solar power used to generate it. It will never be easy to store. Hydrogen is the smallest element, and can move through solid objects over time. It is violently explosive. You think these EV fires you see all the time are bad? They're nothin…

> Hydrogen is supported only to draw support away from EVs.

I always find this false hydrogen versus batteries narrative bizarre.

Hydrogen fuel cell vehicles are EVs. It isn't an exclusive choice between hydrogen or batteries. Choose both hydrogen and batteries, both FCEVs and BEVs.

In any case, if you want your EV to be manufactured with green steel then you want hydrogen to be used in the production of that steel:

https://www.energy.gov/sites/prod/files/2017/05/f34/fcto_may...

https://arstechnica.com/science/2022/06/the-race-to-produce-...

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#105

Post by ncmncm » Wed, Jun 22, 2022, 1:10 AM UTC

tambourine_man wrote: post #44

I can get behind the round-trip inefficiencies if it gets terribly cheap, but I can't imagine how storage and transportation can ever be economical. We are trying to contain the most volatile substance in the universe. It needs incredible pressure just to be manageable and even then, it freaking diffuses within the steel walls themselves, leaking and making it brittle over time. It's not hard to imagine single proton…

Handling LH2 is really not so different from handling LNG, which we do in the millions of tons.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#106

Post by ncmncm » Wed, Jun 22, 2022, 1:12 AM UTC

Jistern wrote: post #100

ncmncm wrote: post #97

Earlier quoted context omitted.

Ammonia will not be used in urban vehicles. It will be used in farm equipment, and in place of bunker oil in ships, and burned in combined-cycle turbines in times when wind and sun are not providing, and other, cheaper storage has been used up.

Ammonia seems too dangerous. With cheap electricity from solar and wind, cheap hydrogen seems like a better answer. Sure, it's not a perfect answer, but it seems better because it seems much safer. As recently as approximately 200 years ago steel was very expensive, as was aluminum. Now both of those materials are cheap and used in a plethora of applications. Cheap electricity will similarly enable us to cost-effecti…

You will see a very great deal of anhydrous ammonia stored, transported, and used, but will not be asked to handle it yourself. Shipmakers are already gearing up to retrofit ships with ammonia tanks, to burn in existing engines. Probably important ports will start to forbid docking of bunker-oil craft.

You probably will not have much contact with hydrogen, either.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#107

Post by moralestapia » Wed, Jun 22, 2022, 1:14 AM UTC

ncmncm wrote: post #81

moralestapia wrote: post #60

Earlier quoted context omitted.

My bet is on ammonia but yeah the economics will get tricky as producers are going to ask themselves "will I get more money if I sell this as fertilizer or as fuel?" Kind of what happens with corn-based bioethanol, where they have to compete with the regular food market and viceversa.

There is no natural upper limit on ammonia produced. Add more panels, make more ammonia. The panels, placed intelligently, do not use up land needed for other things. Compare to bioethanol, strictly limited by acreage under cultivation.

>There is no natural upper limit on ammonia produced.

Weird, I've heard there's some fertilizer shortage going on ...

Anyway, the point is why would sell ammonia as fuel for $20 when you could sell it as fertilizer for $40+.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#108

Post by katmannthree » Wed, Jun 22, 2022, 1:17 AM UTC

ncmncm wrote: post #99

scythe wrote: post #96

Earlier quoted context omitted.

The problem with any fuel containing H2 in any existing engine is hydrogen embrittlement. Hydrogen is a reactive gas that attacks steel. Ammonia fuel cells have a comparable weight proposition to hydrogen at small sizes because the tank is so much lighter. I think that has legs (or wheels?). For stationary storage, the ammonia-CO2 adduct is a solid, which is nice.

Hydrogen embrittlement is always hyped to the sky. It is not a serious problem unless you are trying to keep warm, gaseous hydrogen under high pressure. So, don't. Furthermore, aluminum is quite resistant to embrittlement. Of possibly greater moment is that it leaks, and has ~200x GHG over CO2 (including secondary effects). Leaks are not dangerous in the open, or in confined places with positive airflow, but punishme…

> trying to keep warm, gaseous hydrogen under high pressure

Which of course nobody would do? Unfortunately, those are the circumstances in which H2 is made from fossil fuels and likewise the circumstances under which it is combusted in turbines. You can't just handwave materials compatibility away.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#109

Post by ncmncm » Wed, Jun 22, 2022, 1:18 AM UTC

lukeschlather wrote: post #76

derriz wrote: post #25

I don't see hydrogen playing any role for energy storage or grid demand balancing. Even if all the technical and engineering challenges associated with storing and transporting it safely could be addressed, I just don't see how the economics of green hydrogen is supposed to work. The round-trip energy efficiency of electrolysis-fuel cell is poor - currently about 40%. The counter-argument is that such inefficiency do…

> it means leaving your capital-expensive electrolysis plant idle for half or 2/3rds of the day. I think that's an exaggeration, and neglects the possibility of overbuilding solar/wind. It may mean leaving your relatively low capital expenditure wind and solar farms 50% underutilized for half the day but the benefit here is that you can guarantee a 95% capacity factor year-round for the expensive electrolysis plant.

Electrolysis equipment will move relentlessly toward 100% usage, drawing down other forms of storage, and transmission lines, when top-line generation flags. You might turn it off just when demand peaks.

We absolutely will overbuild solar and wind to have enough to charge up storage for 24-hour use. Making hydrogen will be such a use.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#110

Post by ncmncm » Wed, Jun 22, 2022, 1:26 AM UTC

UnchartedSystem wrote: post #45

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Guess you mean dimethoxyethane, or "glyme".

To "extract bitumen" appears to mean mine tar sands for hydrocarbons.

I expect demand for mined oil to decline to the point where only the absolute cheapest producers of it will be able to stay in business. Extracting from tar sand will be right out.