To me, this suggests using hydrogen to fuel large scale use (e.g., generating electricity) where the water vapor can be captured, processed, and distributed for large-scale water use (e.g., cities, irrigation). Nebraska has thousands of those circular sprinkling system in the state. Since it’s on the rift, generate power for the area by burning it and use the resulting water to irrigate crops in the area.
Using liquid hydrogen to power cars seems more difficult because it is less energy-dense that distillate fuels and water capture probably is not possible.
I don’t know the cost, but it sounds like a win/win to me.
Converting water vapor to water is a simple condensation matter. This would be easy for power plants and factories.
But then, what do you do with the thousands of gallons of water? Takes infrastructure.