Have you heard of "lamp gas"? It used to be delivered via cast-iron pipes to every house, factory, and street light. It was a mix of carbon monoxide and hydrogen. There was no problem with embrittlement, because the pressure was low. Natural gas is today carried (in the same pipes, some places) at quite low pressure. Germany could start admixing H2 anytime, although feeding it to NG turbines would be a better immediate use.

Anyway aluminum is quite resistant to hydrogen embrittlement.