On Apr 9, 3:05 pm, wrote:
cavedweller wrote:

The engineering problem for wide spread use is hydrogen embrittlement.

For instance?

For instance the only existing distribution plumbing that will handle
hydrogen is on liquid hydrogen trucks; you can't run it down existing
gas pipe lines.

Hmmmm. I see that I should have asked rather "Of what?" (relative to
hydrogen embrittlement)