[pfdietz]

These are not abandoned salt mines, they are deliberately created caverns in salt domes. The cost of creating them is included in the capital cost ($1/kWh capacity).

Hydrogen could also be stored in depleted gas fields and in deep saline aquifers. The storage capacity available is more than adequate.

[Manfredo_1]

For the third time, storage is only one part of the puzzle. We also need a way to cheaply electrolyze water into hydrogen, compress it into the storage facility, and then use it to generate electricity. Nobody doubts that you can pump hydrogen into a big cave. What's dubious is transforming this into a usable energy-storage facility.

We haven't done this to provide 100 MWh of storage. How on earth can we be confident it'll be easy to provide 1 TWh of storage, or 10 TWh?

People mostly talk about lithium ion storage because that's what's actually available, besides geographically limited options like hydroelectricity. Until there's a company that's building dozens of gigawatt hours of hydrogen storage it's a moot point. It's a technology that exists the laboratory, not one that's commercially available.