Cheap, sustainable hydrogen through solar power • Hacker News Board

Re: Cheap, sustainable hydrogen through solar power

#121

Post by kwhitefoot » Tue, Jan 10, 2023, 7:06 PM UTC

mrleinad wrote: post #52

kwhitefoot wrote: post #50

Unless 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.

> a way to store the energy that can be measured in weeks,

My Tesla Model S does that pretty efficiently. And for static batteries there are plenty of alternatives that don't use difficult to source elements.

> You also need to transport it.

We have a grid to do that already, with HVDC interconnects we can even sell it to places where the sun is not shining.

Re: Cheap, sustainable hydrogen through solar power

#122

Post by ephbit » Sun, Jan 15, 2023, 2:01 PM UTC

fbdab103 wrote: post #19

I am waiting for the day when there is an affordable ( Is anything like that on the horizon? Or do all of these liquid fuel synthesis options require industrial pressures/volumes/input electricity so as to forever be out of reach from residential synthesis?

This [1] comment mentions https://homepowersolutions.de/

There's also a recent HN topic [2] about it, but without any comments yet.

[1] https://news.ycombinator.com/item?id=34298804

[2] https://news.ycombinator.com/item?id=34302276

Re: Cheap, sustainable hydrogen through solar power

#123

Post by ephbit » Sun, Jan 15, 2023, 3:08 PM UTC

miahi wrote: post #29

35mm wrote: post #26

Earlier quoted context omitted.

This is currently the Lavo hydrogen electrolysis product for home use [1] However the storage tanks are quite small. I would prefer if they made the hydrogen production and storage separate, so you could save up hydrogen in the summer to use in the winter. [1] https://www.lavo.com.au/

Hydrogen storage is not something that you really want to do at home, especially in "saving up" quantities. It is quite happy to explode, you need tremendous pressures and low temperatures for efficient storage, and also hard to contain (many "normal" materials are permeable to hydrogen). [1] [1] https://en.wikipedia.org/wiki/Hydrogen_safety

> Hydrogen storage is not something that you really want to do at home, especially in "saving up" quantities. It is quite happy to explode, you need tremendous pressures and low temperatures for efficient storage, and also hard to contain ..

Agree, hydrogen storage is not something you do as easily as say piling up some fire wood.

On the other hand, it's totally possible to do at home and it is being done. Hydrogen can be stored in regular gas cylinders. See the realized projects from Home Power Solutions [1].

If these cylinders are located outside, explosions should be rather unlikely due to ventilation.

[1] https://www.homepowersolutions.de/en/picea-plus/

Re: Cheap, sustainable hydrogen through solar power

#124

Post by ephbit » Tue, Jan 17, 2023, 11:31 AM UTC

cduzz wrote: post #101

adrianN wrote: post #85

Earlier quoted context omitted.

It's probably more efficient to centralize storing weeks worth of energy.

Many people in rural New England have or wish they had secondary power generation because you need that local energy more often when there are external events that likely also break the grid (big snow storm). The chain of events is "once in a gazillion century storm wipes power to huge region; millions of households are stuck without power, power company can't go out and fix all the broken things for weeks/months, ma…

> Maybe if you can figure out how to stick a carbon or two or three onto those hydrogens you'd be in business, but it's hard to get those carbons.

Or maybe you stick three hydrogen atoms to one nitrogen atom and have ammonia.

It's pretty obvious that the single most important reason why the vast majority of machines/engines runs on hydro _carbons_ instead of hydro nitrogens, is that hydrocarbons have been humanity's most important energy source for centuries.

So it makes sense, everything is geared towards them.

But for the future, ammonia appears to be a much better choice, because nitrogen is readily available and the only thing that's missing is matured tech that runs on ammonia. Fuel cells, engines, ...

IIRC there are already container ships being built that run on ammonia.