hydrogen leaks may be an issue when you store it at 600 atmosphere pressure like ICI do - it probably makes more sense to pipe it at lower pressures for use as required, as we do for domestic gas today, rather than for applications that need us to each have a large store.

Those of us old enough to remember the old coal derived 'town gas' are recalling a mix of about 60/40 hydrogen and carbon monoxide, so both quite explosive and very poisonous. One thing that was not a problem of the day was leaks from the lead or black iron pipes, or at least no more of a problem than it is now with methane  - but the key thing is that the street pressure is only a fraction of a bar, and at the meter it used to be further regulated down to a pressure equivalent to blowing bubbles in a few inches of water.

Leaks from high pressure H2 lines can actually self ignite in air which is very nasty in a confined space, especially as in bright light the flame is hard to see until you are nearly in it.

hydrogen leaks may be an issue when you store it at 600 atmosphere pressure like ICI do - it probably makes more sense to pipe it at lower pressures for use as required, as we do for domestic gas today, rather than for applications that need us to each have a large store.

Those of us old enough to remember the old coal derived 'town gas' are recalling a mix of about 60/40 hydrogen and carbon monoxide, so both quite explosive and very poisonous. One thing that was not a problem of the day was leaks from the lead or black iron pipes, or at least no more of a problem than it is now with methane  - but the key thing is that the street pressure is only a fraction of a bar, and at the meter it used to be further regulated down to a pressure equivalent to blowing bubbles in a few inches of water.

Leaks from high pressure H2 lines can actually self ignite in air which is very nasty in a confined space, especially as in bright light the flame is hard to see until you are nearly in it.