Mostly the bit where I can't actually buy them. Do you know of any good suppliers of kw-scale fuel cell systems that are cost-competitive to lithium or lead-acid batteries? Because that would be great, I just can't find them.

I think hydrogen storage is still one of the difficult parts.

I've never done any analyis on the performance of them. I should, the dual nature of hydrogen usage (cooking and power) makes it very intersting to me.

Hydrogen storage tank seems to be available but keeping it all under pressure, i've not seen many people talk about that.