Austria already ~70% renewable, as has a lot of hydro power....

Austria already ~70% renewable, as has a lot of hydro power. They also have decent amount of wind power, and ADX' partner is a midsize player with about 5% market share.
Problem with wind power is that in the near term there is excess capacity at wrong time of day (higher wind during off-peak periods).
Will take big investment in storage - both battery and H2 production and storage ...
Will happen, the big storage companies, big utilities, and big industrial CO2 emitters will take the lead.
If ADX still owns their depleted fields, they will be price takers for storage. Price will be set by big storage operators (RAG, Uniper)
ADX does not have the capital to become significant player in H2 production, they will probably be asking you for money to invest in their initial pilot plant - hydrolysers aren't cheap.