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Cheap, green hydrogen would be a breakthrough in clean energy

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

#31

Post by vkou »

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.

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

#32

Post by causi »

hnlmorg wrote: post #24
causi wrote: post #18

It's too late for hydrogen. For hydrogen to be green is has to either A) be more green than storing the generating power in batteries and using it from there or B) be created with something other than electricity. It's too late for A, batteries are already too good. As for B), feel free to come up with some kind of metamaterial that can produce hydrogen mechanically and in doing so bypass the efficiency loss of elect…

> For hydrogen to be green is has to either A) be more green than storing the generating power in batteries I thought batteries had some pretty toxic elements inside them? I don’t know much about using hydrogen as a power source so I’m interested to understand how it’s less green than batteries.

Correct. For hydrogen to be green it has to be more green that producing and using batteries. We're already past that point. Well past it, in fact. The generation-to-tires efficiency of BeVs is 77%. For hydrogen it's 33%. Modern fuel cells have an H2 to electricity efficiency of 55%. You could make that 100% and it would still be less green than using batteries.

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

#33

Post by bryanlarsen »

oh_sigh wrote: post #9

Why are we all wrapped up with hydrogen when we already have a perfectly adequate hydrocarbon infrastructure? Sure, digging up old buried hydrocarbons and burning them isn't good, but couldn't we start synthesizing light hydrocarbons using green technology, so at least those usages are carbon neutral?

Yes, I believe that this has a lot more promise than using hydrogen directly. It's even less efficient than hydrogen, but there are tons of use cases where the cost of replacing old infrastructure is more expensive than the efficiency gains from electrification.

Or if your rocket runs on methane.

https://terraformindustries.com/ is just one example of companies going after this market. SpaceX is also getting into it.

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

#34

Post by foobarian »

liketochill wrote: post #5
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…

I know ammonia has safety challenges as well, but transport and storage of ammonia is routine. I believe there are new developments in using ammonia for hydrogen storage and transport, so ammonia has potential to enable hydrogen to be the fuel of the future.

And what would ammonia be? Yellow hydrogen? :-)

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

#35

Post by plutonorm »

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 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 comes out of anyones mouth, it's all designed to further some agenda or other. There's continuous information warfare going on all around us.

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

#36

Post by syntaxing »

I did a grad course on energy generation. I think the biggest problem for hydrogen is that there is not enough money in it (kind of like nuclear). IMO, a hydrogen fuel cell PHEV would would the sweet spot for a “green vehicle”. Like 70% today of hydrogen is made from fossil fuel because the reality is, there’s just not enough incentive to shift from that (like how we use so much plastic). If we put the same amount of money and research into hydrogen that we did with batteries, non platinum fuel cell and solar hydrogen is definitely technically feasible.

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

#37

Post by syntaxing »

goethes_kind wrote: post #19

I think the thing with hydrogen that people miss is that you have to accept that there will be huge energy losses. But then also have to remember that hydrogen allows you to easily handle and transport energy in the form of stable hydrocarbon fuels (if combined with power-to-gas) for example. Maybe something like scaling a solar farm to 300% of needed capacity and then combining it with hydrogen storage/transportatio…

A standard car is like 25% efficient… a PEM fuel cell is like 40% efficient

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

#38

Post by hannob »

causi wrote: post #18

It's too late for hydrogen. For hydrogen to be green is has to either A) be more green than storing the generating power in batteries and using it from there or B) be created with something other than electricity. It's too late for A, batteries are already too good. As for B), feel free to come up with some kind of metamaterial that can produce hydrogen mechanically and in doing so bypass the efficiency loss of elect…

How do you make ammonia with a battery?

The target use case for hydrogen isn't the cases where you can use a battery. It's all the places where that doesn't work.

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

#40

Post by giantrobot »

phkahler wrote: post #13
ZeroGravitas wrote: post #7

> the world will have to get better at balancing energy supply and demand so we don’t go dark when the sun isn’t shining or the wind isn’t blowing. Thanks Bill, that's really helpful, was there really no other way you could have phrased that? > 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.…

Quoted post unavailable.

The colors of hydrogen have specific meanings.

Green hydrogen - hydrogen derived from water electrolysis, ostensibly from renewable electrical sources so no greenhouse gases are produced

Blue hydrogen - hydrogen derived from hydrocarbons, produces greenhouse gases as waste

Pink hydrogen - hydrogen from water electrolysis from nuclear electrical sources, no greenhouse gases produced

The description of "green" hydrogen is only tangentially related to the colloquial use of "green". So long as no greenhouse gases are produced the hydrogen is labeled green.

The use for hydrogen isn't an energy source but as an energy transport and storage. So "green" hydrogen is still "green" in the colloquial sense despite its inefficiency if it doesn't produce any greenhouse gases in the pipeline.

All that being said, I personally think hydrogen is stupid as a transport and storage medium for electricity. Electrical transmission lines will always be more efficient than a theoretical hydrogen pipeline. A chemical battery has a lot less that can go wrong than compressed hydrogen storage. About the only place it even starts to make any sense is grid-scale storage and even then I don't think it can practically beat other storage systems.

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