[awjr]

Thought storing Hydrogen was notoriously hard because it can penetrates rather effectively through pretty much anything.

[chrisb]

I can't find a reference now, but as I understand it this isn't so much of an issue at low pressure.

Apparently underground low pressure storage has been used successfully: http://en.wikipedia.org/wiki/Hydrogen_storage#Underground_hy...

[KaiserPro]

http://en.wikipedia.org/wiki/Coal_gas

Seemed to be not to hard with town gas (which was >50% hydrogen)