A lot of the discussion here is around hydrogen fuel cells for cars and aviation. Which would be cool. But the real reason we need “green” hydrogen now is for making steel and cement: https://www.vox.com/energy-and-environment/2019/10/10/209042...
> As you can see, every low-carbon alternative raises costs more than 50 percent above baseline. The only ones that don’t raise it more than 100 percent are CCS (of the heat source only), blue hydrogen, or resistive electric in places with extremely cheap and plentiful carbon-free energy.
> The alternative that climate hawks would most prefer, the carbon-free option that would work best for most applications, is green hydrogen. But that currently raises costs between 400 and 800 percent. Ouch.
Green hydrogen is by far the most expensive option. 3-4 times more expensive than electric heat. That's the direct opposite of "the real reason we need “green” hydrogen now is for making [...] cement".
This new work will hopefully make green hydrogen cheaper. But if you're using electricity to make that hydrogen, i don't think it can ever be cheaper than electric heating.
For aviation, LH2 has such fantabulous efficiencies that we can expect to see all serious air transport switched over by 2050 (providing civilization doesn't collapse first).