this post was submitted on 11 Mar 2026
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You can generate hydrogen from electrolysis.
Electrolysis efficiency is about 70% and you can store the hydrogen in pressurized underground caverns for a year or longer using another 0.12 kWh per kWh of hydrogen stored, which makes a total efficiency of around 0.6 kWh of hydrogen generation and storage for every kWh of electricity that you put in. (Source)
So if your electricity costs 6 ct/kWh (current LCOE of solar in many places), then hydrogen is gonna cost 10 ct/kWh to generate and store with current technology.
Currently, natural gas is around 5 ct/kWh, so solar would have to become a little bit cheaper to make it economically competitive.
Edit: to clarify, the 5 ct/kWh for natural gas is the gas alone; electricity from natural gas is more expensive than that (around 12 ct/kWh) and more expensive than solar.
What are you going to store hydrogen in to make this remotely viable? You lose like 60% of hydrogen within 7 days with current tanks and seals.
The new sodium batteries make this completely pointless from a cost and efficiency context
Hydrogen can be stored for years.
Hydrogen’s small molecular size facilitates permeation through many conventional materials, leading to leakage and potential embrittlement of metals. These characteristics create "unique" (read: expensive) engineering challenges.
And if you store it as a liquid that's when you enter the whole cryogenic problem, seeing it needs to be cooled to over - 225c
Even with advanced insulation, liquid hydrogen storage experiences unavoidable boil-off at rates of 0.3-3% per day, creating both economic and safety challenges.
And if you could make hydrogen via electrolysis, even with some uber wunderful unobtanium catalyst then you're still just waiting electricity that we can store far more efficiently in batteries (and with sodium batteries hitting the market there is going to be a huge revolution in battery economics and tech that will make lithium look like a drop in the ocean.
The problems are mostly solved already. You wouldn't use metals known for hydrogen embrittlement. Often times, you'd use something else, like HDPE or fiberglass that avoids this issue. Storage facilities can even be naturally occurring geological features, like salt caverns.
You would only use LH2 for specific cases, specifically where you are expected to use up the hydrogen quickly. But even this is changing, as self-refrigerating systems are being developed, allowing for very long-term LH2 storage.
We already can make hydrogen via electrolysis. This is a long-solved problem. Efficiency is not that relevant. The main limitation of batteries is that you simply cannot make enough of them. There are huge resource limitation problems. Meanwhile, hydrogen can be made from water and is effectively unlimited as a resource.
is home hydrogen a thing? i was wondering before, if it works in cars, why is it not in houses?
hydrogen scales well if you use big industrial setups, both for generation and for storage.
basically, bigger tanks are cheaper (consider higher volume/surface area ratio) and in fact the best tanks might simply be naturally occurring underground caverns. you can't have these at home.
Technically it could work. However, traditional batteries make a lot more sense. Hydrogen makes some sense for a vehicle because it can be more energy dense (it actually only makes sense for large trucks). However, it has to be stored at cryogenic temperatures. In a place where you probably don't care about mass or space much, other battery technologies are far better, without the added cost of cryogenic cooling and having to deal with hydrogen, which leaks through anything.
You would store it as a pressurized gas in this scenario. You would only use liquid hydrogen in specific situations.
Hydrogen gas is really hard to store. It is tiny, so it's basically always leaking, no matter how good your seal is.
Underground caverns can store it for years. This is simply not true.
What do you mean it isn't true? It's a well known fact. It's just a proton and an electron, so it's absolutely tiny. There is almost no way to seal it perfectly, especially in gaseous form. It's always going to leak. Even for rockets this is an issue. You can make that amount relatively small, but it pretty much always has some loss.
Caverns may make sense for large-scale solutions, because the quantity is so large compared to the loss. Most people don't have massive caverns under their house though, nor do they have a need for that large of a quantity.
Even in tank form, you can store it for months. It is not much different than CNG.
Large-scale solutions matter too. The utility companies can utilize such a thing.
The question was specifically about home hydrogen. Yes, it makes sense for utility companies, as well as large vehicles, as I said before. It's a great solution to turn renewables into a shipable commodity. Home use though doesn't make sense. A regular battery has much better properties for home use.
The same applies for home hydrogen storage too. Compressed hydrogen is good for months. Another option would be metal hydrides which apparently last a long time too. The problem is that you simply cannot power your house entirely with batteries alone.
There's a engineer that did it in his backyard. I'll see if I can find it when I get home.
https://www.youtube.com/watch?v=djg_l7cEtWg
https://hydrogenhouseproject.org/index.html
That sounds cheaper than battery storage (which at latitudes bigger than yours can get very expensive since there's little to no sun in the winter), and I'd assume more environmentally friendly than mining all that lithium as well.
How expensive is it to build out said caverns for this use, particularly if there aren't many natural ones available?
basically the caverns that are being considered/used for this are the same caverns that natural gas was extracted out of in the first place ... they clearly held some sort of gas fine for millions of years, so certainly they're gonna store a bit of hydrogen too.
Not to rain on your parade, but hydrogen and natural gas aren't really comparable for storage. The natgas molecule is 8x heavier and MUCH larger than a molecule of hydrogen. Just on the size alone, hydrogen can slip through just about everything and needs to be stored at cryogenic temperatures. I don't think rock is going to be as good of a storage media as you'd assume.
sure it's gonna leak but if the rate of leakage is slow enough, you can ignore it :)
Oh that makes sense.
We just don't have any natural gas production in Estonia lol. Perhaps the shale mines could be used. Unfortunately the biggest one had its permit extended till 2049 recently. Also I think they get filled with water naturally (they pump out a lot of dirty water), so I suppose the walls aren't actually completely sealed naturally.
yeah, geological availability might vary