You are confusing energy storage and fuel storage. I am talking about CAES, it uses electricity to compress air and feed that into a container, like a metal cylinder or caverns lined with impermeable material. When you need electricity, you release the air through a generator and produce electricity.
Hydroelectric, compressed air and batteries have round trip efficiency of ~80%.
The facility you linked produces and stores chemical fuel, and can't even convert it back into electricity. It is really easy to store insane quantity of fuel, just like we can store loads of oil.
The kicker is that production of Hydrogen and other e-fuelds is less than 50% efficient, and converting them back to electricity is another 50% loss. Compression for storage and transportation mean further losses. So the overall round-trip efficiency is expected to be about 25% or lower.
It is probably possible to build an economy based on e-fuels, and that's what many oil companies are pushing for. They are probably the only viable way to achieve seasonal storage. It's a different set of tradeoffs.
Another system used a hydrogen-side electrode made of foamed metal immersed in water, where the surface area presented to the water was therefore very large, and the small pore size limited the hydrogen bubbles' interference with contact between water and electrode surface.
Cost. Fuel cells require quality manufactured membranes that also require regular maintenance and replacement. Getting volume with them is also a hard problem.
Thermochemical hydrogen offers the best prospect for hydrogen production if it can be worked out, because the whole-process efficiency from solar or nuclear heat can exceed the practical limits of water electrolysis. Most recent work focuses on the copper chloride process (which uses an electrolytic step) [1]. The best purely thermal cycle is sulfur-iodine, but running the process sustainably has yet to be achieved due to the corrosive nature of the intermediates.
Russians did that at some point in the 70s 80s. They pumped compressed air into some salt mines and that worked well until one of the mines sprung a leak and blew the mountain up
Hydroelectric, compressed air and batteries have round trip efficiency of ~80%.
https://www.sciencedirect.com/topics/engineering/compressed-...
The facility you linked produces and stores chemical fuel, and can't even convert it back into electricity. It is really easy to store insane quantity of fuel, just like we can store loads of oil.
The kicker is that production of Hydrogen and other e-fuelds is less than 50% efficient, and converting them back to electricity is another 50% loss. Compression for storage and transportation mean further losses. So the overall round-trip efficiency is expected to be about 25% or lower.
It is probably possible to build an economy based on e-fuels, and that's what many oil companies are pushing for. They are probably the only viable way to achieve seasonal storage. It's a different set of tradeoffs.