Why not store it in hydride form? (Edit: my bad, should read article first, then the comments.)

That's said to be even more energy-dense than liquid H2, and it's obviously much safer.

Guessing the answer is that it requires heat to liberate the gas, and/or makes us even more dependent on rare earths.

AnotherGoodName 3 days ago | parent | next [-]

That's better. In fact the best option is to store it as methane. Electricity to methane production has the same efficiency as hydrogen. It's just a small step across to allow the hydrogen to bond to free carbon when producing it and doesn't really hurt the overall efficiency of hydrogen production from electricity since the biggest losses are in the production of the hydrogen itself. Both methane and hydrogen production from electricity have the same efficiency.

As methane it's reasonably easily liquified. You also already have a network of natural gas systems that you can utilise this in right now. There's literally fleets of natural gas vehicles today as well as pipelines everywhere. If making hydrogen from electricity was in any way viable we'd already be doing it for the methane networks we have today.

Of course if we start talking like this the myth of hydrogen being green gets blown right out of the water and we realise that storage isn't even the biggest issue of hydrogen. "Hey Toyota why don't we just use your existing CNG cars instead, it'll save us making hydrogen from methane and if we ever do start making it from electricity in bulk couldn't we just make methane similarly?".

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CamperBob2 3 days ago | parent [-]

How do you get rid of the C in the CH4, though?

By the same token, I've always thought it would be interesting if someone came up with a way to retrofit gas stations with something that could split the hydrocarbon molecules without burning them. Then we'd really be able to reuse existing infrastructure (handwaving away the storage-density problem of course, which the subject of this article might help with.)

But same problem... the carbon and the hydrogen really, really like to hang out together.

	▲	AnotherGoodName 3 days ago \| parent [-]
		You take c from the co2 when producing ch4 synthetically. You then reform the co2 on combustion. Fwiw methane to hydrogen and back again is trivial. It’s how hydrogen is predominantly made today. You can indeed make a hydrogen fuel station from methane. It’s just that it’s really really dumb to do that when hydrogen is so inefficient in an engine and so hard to store. You should just use methane all the way.

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philipkglass 3 days ago | parent | prev | next [-]

Improved hydride storage is exactly what the submitted article discusses.

A hydrogen battery that operates at just 90 °C has been developed by researchers from Japan, overcoming the high-temperature and low-capacity limits of earlier methods. The device works by moving hydride ions through a solid electrolyte, allowing magnesium hydride, which acts as the anode, to repeatedly store and release hydrogen at full capacity.

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timerol 3 days ago | parent | prev [-]

TFA is about storing hydrogen in magnesium hydride