> Hydrogen really doesn't like to be stored though. It also ruins any storage vessel it is kept in long term.
It's true that it's the smallest atom, but it's not the smallest molecule. Helium is more prone to escapement since it's not diatomic. Doing a bit of research it looks like aluminum is actually a fine container for pressurized hydrogen (low permeation rates, low embrittlement). You do need to reinforce it (e.g., composite wrapping) if you want to go to high pressures.
>and this makes less since.
FYI, s/since/sense
I think you're over-indexing on efficiency. That's not the only metric that influences success. Suppose that we have an overabundance of intermittent sources of electricity (e.g., wind and solar). Right now there's not much you can do to store it. Batteries are great for smoothing demand over hours or days, but they're quite far from smoothing demand over weeks or months.
So if you're able to cheaply overproduce electricity, it doesn't really matter if your storage process is not particularly efficient. Even at fairly low efficiencies, it's more useful than throwing it away so long as the capital cost of the conversion equipment is low enough to tolerate the intermittency.
As for the cryogenic storage adding an additional efficiency hit - yes, correct. But there's an intercept of marginal cost, storage density, and efficiency where it will be economical to do it. The technology question is if we can deliver that intercept at a lower total cost than other alternatives.
One thing that's really attractive about hydrogen is that the costs are not the processed media. Batteries are full of expensive to mine and refine materials and their storage capacity is more-or-less directly tied to the quantities of used materials. With hydrogen production the media are water and space, both of which are almost free in many contexts. Vehicles aren't really one of them because volume is precious, but for stationary applications it's a completely different story.
It's true that it's the smallest atom, but it's not the smallest molecule. Helium is more prone to escapement since it's not diatomic. Doing a bit of research it looks like aluminum is actually a fine container for pressurized hydrogen (low permeation rates, low embrittlement). You do need to reinforce it (e.g., composite wrapping) if you want to go to high pressures.
>and this makes less since.
FYI, s/since/sense
I think you're over-indexing on efficiency. That's not the only metric that influences success. Suppose that we have an overabundance of intermittent sources of electricity (e.g., wind and solar). Right now there's not much you can do to store it. Batteries are great for smoothing demand over hours or days, but they're quite far from smoothing demand over weeks or months.
So if you're able to cheaply overproduce electricity, it doesn't really matter if your storage process is not particularly efficient. Even at fairly low efficiencies, it's more useful than throwing it away so long as the capital cost of the conversion equipment is low enough to tolerate the intermittency.
As for the cryogenic storage adding an additional efficiency hit - yes, correct. But there's an intercept of marginal cost, storage density, and efficiency where it will be economical to do it. The technology question is if we can deliver that intercept at a lower total cost than other alternatives.
One thing that's really attractive about hydrogen is that the costs are not the processed media. Batteries are full of expensive to mine and refine materials and their storage capacity is more-or-less directly tied to the quantities of used materials. With hydrogen production the media are water and space, both of which are almost free in many contexts. Vehicles aren't really one of them because volume is precious, but for stationary applications it's a completely different story.