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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? :-)
Yeah, so would cheap nuclear power or cheap batteries. I find cheap batteries way more likely then either of those.
Hydrogen is a battery. We have no free source of H2. We have to put energy into making it, storing it, and transporting it. We get less energy back than we put in. The most generous lifecycle analyses that I have seen estimate 60-70% roundtrip efficiency.
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…
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…
I think maybe for cars it’s over but the energy density argument still favors hydrogen so I’d add another option. C) provide greater energy density allowing for heavy equipment, trucks, trains, and planes to use electric power.
It remains to be seen whether existing airframes can be retrofitted with under-wing LH2 tank nacelles, or if we will need whole new airframes.
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.
Ammonia has been mentioned a few times in this thread, but I will expand a bit, because I believe it is the most promising hydrogen-based approach. Essentially, the idea is to use ammonia directly as fuel. There is an ARPA-E funded project (that I'm currently failing to find) that cracks ammonia into hydrogen and nitrogen using heat. They claim that they can create a mixture of H2 and ammonia that will burn at any re…
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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+.
Supply will rise to meet demand.
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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…
Having some cheap long-term energy storage option is one way to solve that problem, but another is better power grid interconnection. For instance, Chicago could get solar power from Chile in the winter time to buffer out the seasonal variability. Or if they didn't even want to have to maintain a smaller buffer to deal with day/night cycles, they could get solar power from, say, Algeria and Australia depending on tim…
This is basically a proposal to power all of Americas at night using solar deployment in Australia? This is far outside the realm of technical and infrastructural feasability.
What about reliability? UK power connection to france has burned down a few months ago and it will take 2 years to fix, and it only moves like 2 GW
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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…
Exactly. The solar energy that can be captured throughout the year using not much more than the roof area of a single-family home would be enough to cover its entire annual energy needs, both for electricity and heating. The problem is that you need to store about 30,000 kWh of energy over a period of several months. That’s on the order of 400 Tesla Model 3 batteries worth of storage. Not only is it prohibitively exp…
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> 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.
Electricity is currently much more expensive than it was last year.
Aluminium refineries use OP-ex heavy, so the day your dream of cheap electricity materialises, aluminium will become nearly free