> As humanity tries to reduce its carbon emissions
It's time to change this stereotype. Humanity tries to reduce its greenhouse gases emissions, and CO2 is not the biggest problem.
Cheap, sustainable hydrogen through solar power
51–60 of 124 posts
Re: Cheap, sustainable hydrogen through solar power
#52Unless you need hydrogen for a capability that only hydrogen has it is much more efficient to use solar electricity either directly or to charge batteries.
In those parts of the globe where it makes sense to use solar, and during the day, yes.
For everything else, you need a way to store the energy that can be measured in weeks, not hours. You also need to transport it. And you need to stabilize the energy output not to be entirely dependent on whether the sun shines. That's why hydrogen might be a good energy reservoir.
Re: Cheap, sustainable hydrogen through solar power
#53Is hydrogen cheap to transport, cheap to store, and cheap to use though? I thought making it was only a small part of the problems with hydrogen.
You can add hydrogen to natural gas (using existing pipelines and storage), and so slowly replace that. No changes to existing infrastructure needed up to maybe 20% I think.
hydrogen worsens the impact of methane in the atmosphere and as such simply pumping hydrogen through existing infrastructure sounds pretty dangerous.
https://theconversation.com/dont-rush-into-a-hydrogen-econom...
https://agage.mit.edu/publications/global-environmental-impa...
more skeptically, given that green hydrogen remains a pipe dream, it's both a useful delaying tactic for switching to electricity and furthering investment in fossil fuels, which must stay in the ground if we are to have any hope of staying below 1.5c.
https://www.carbonbrief.org/new-fossil-fuels-incompatible-wi...
Re: Cheap, sustainable hydrogen through solar power
#54Is hydrogen cheap to transport, cheap to store, and cheap to use though? I thought making it was only a small part of the problems with hydrogen.
No, too many losses. Same problem with storage. Use isn't that expensive, fuel cells do exist. The problem with green hydrogen (made with electricity) is the inefficiency. It's only good for storage when you have already filled every battery and pumped hydro storage you have and are still making an excess. Electricity -> hydrogen -> electricity conversion is so hilariously inefficient that even petrol engines can bea…
No petrol engine can match a fuel cell on efficiency. Especially once you realize the existence of refining losses.
Re: Cheap, sustainable hydrogen through solar power
#55Earlier quoted context omitted.
I don’t understand that comparison. You can’t use electricity to make petrol, right?
Synthetic fuels can be created with electricity. But, again, the efficiency is laughable. The amount of energy lost in the conversion is so huge that it's not viable unless you've got crazy levels of overproduction. But my comparison was about the fact that petrol engines convert only 20-30% of the energy in the fuel to actual motion - everything else is lost in friction and output as heat. Toyota had a prototype eng…
Fuel cell vehicles also use electric motors. They will not lose to combustion engines on efficiency. You seem to contradict yourself on how you think hydrogen vehicles work.
Re: Cheap, sustainable hydrogen through solar power
#56Earlier quoted context omitted.
Odd comment phrasing, ChatGPT? Sure, so in the crust it's as common as silver. But that, the mean average, is hardly what matters- there won't be much in beach sand, but find the right copper-porphyry deposit and it's there as common as gallium ~50ppm. It's also a prime example of why the world needs to better recycle electonic waste, indium-tin oxide (ITO) thin film displays from the tip are a better source of indiu…
If there had not been a few kinds of mineral deposits where the indium concentration is much higher than its average, while still being very low, indium could not have been used for anything, as its price would have been too high. Even so, because the total amount of indium in the Earth's crust is about 200 times less than that of gallium, and they are concentrated by similar geochemical processes, it is likely that…
> Even so, because the total amount of indium in the Earth's crust is about 200 times less than that of gallium, and they are concentrated by similar geochemical processes, it is likely that the ratio between their exploitable reserves is about the same.
Ahh, reasoning ("likely that").
And yet, empirically, Gallium and Indium are found in similar porphyry-type mineral deposits at similar ppm concentrations .. despite being both rare and hard to find elsewhere (with indium being more or less as common as silver in the crust).
I get it - I have a strong math background and can understand your "reasoning" from the concentrations .. but then I spent a decade or so in exploration geophysics and then did the back end of a fairly authoritive global scale mineral resource database which changed my outlook on things somewhat.
I also have a shovel handling bob cat driving view of what it's like to mine in excess of 800 million tonnes of reserve depoit per annum and a production engineer level overview of various post processing circuits to extract concentrates for further processing.
Re: Cheap, sustainable hydrogen through solar power
#57Impressive idea. Hope they get a better efficiency factor.
On a side node, you can already add Hydrogen to your home. There is a startup in Berlin, DE which sells complete systems for home: solar roof, heat pump, electrolysis device, bottles and ventilation system.
During summer you fill the bottles with H2 and during winter you consume it.
I'm not affiliated with them. The price before Corona for the whole system was around 65k Euro and now around 100k Euro.
https://www.homepowersolutions.de/en/product/ Picea is the name
Re: Cheap, sustainable hydrogen through solar power
#58Unless you need hydrogen for a capability that only hydrogen has it is much more efficient to use solar electricity either directly or to charge batteries.
Yes hydrogen is has a pretty terrible volumetric energy density. In gas form stored at 200 bar, you'd need about 18 truckloads to math the amount of fuel in a single truck load of petrol. In liquid form stored at a few degrees above zero it gets a bit better. It's "only" 2.5 times less dense than lng. Of course cooling and keeping the gas at that temperature is not free. It takes energy. And as it heats up, you have to boil some of it off. So, it doesn't store that well for longer time in liquid form.
So, that makes shipping or trucking around hydrogen spectacularly uneconomical. Most hydrogen produced today is used onsite. Mainly for things like fertilizer production. Moving hydrogen around at scale is an unsolved problem. Gas pipes (after they are re-enforced) could work of course. But some of it would leak. And hydrogen mixed with air is not a good thing to have in your house.
The same property also makes using hydrogen as a fuel in planes or shipping unpractical: most of your plane/ship would be taken up by the enormous volume of hydrogen you'd need to move it around.
Michael Liebreich's hydrogen ladder is a good reference here. https://www.linkedin.com/pulse/clean-hydrogen-ladder-v40-mic...
In it he organizes different use cases by their economical value. Things like road transport and domestic heating are at the bottom of the scale (i.e. you could do it but it would be very inefficient and costly). Near the top are some of the more realistic things, some of which are already being done.
Instead of moving hydrogen to where you implement those use cases (e.g. steel making), it would be more practical/logical to move the use case to where you can produce the hydrogen the cheapest. The bigger the energy need, the higher the savings. You basically compete on energy cost.
Re: Cheap, sustainable hydrogen through solar power
#59Earlier quoted context omitted.
Then why do the actual people who work with hydrogen worry about transport losses if you just need a thick enough tank? In Michael Liebreich’s Keynote Speech at World Hydrogen Congress 2022[0] he speaks about the problems of shipping hydrogen. you get around 1% of loss PER DAY (0.1% for LNG). And because of the huge tanks the energy capacity is 1/4 of a comparable LNG carrier. The economics just don't make sense. [0]…
The talk is about liquefied gas. Bottled gas has way too low density to put it on a tanker. The losses are due to boil-off, not due to leakage.
In gas form, hydrogen is much worse. You need about 18 truckloads of hydrogen stored at 200 bar to match a single truck load of diesel in terms of energy.
Re: Cheap, sustainable hydrogen through solar power
#60Earlier quoted context omitted.
> Just put it in a gas bottle. is a bit of an understatement. Consider that a household LNG gas cyclinder (propane if you're central north american I guess) is typically built to contain between 100 and 200 psi whereas hydrogen requires high pressure tanks to contain between 5,000–10,000 psi. That's a factor of 50 difference in required containment pressure capability.
Standard industrial gas bottles are 200 or 300 bar (2900 or 4350 psi for the metrically challenged). They work just fine for storing hydrogen [1]. [1] https://www.lindedirect.com/resources/gases/hydrogen
That's indeed how hydrogen is transported around today. The thing is, the volumetric density of hydrogen is quite bad. About 3x less energy than methane in gas form, which is similar to the difference in energy density in liquid form too.