When looking at hydrogen fuel tanks, they often give the capacity in terms of "standard litres". However, I can't find a definition of what this is.
I assumed this may mean a litre of hydrogen gas at room temperature? If so, is this at standard air pressure or is it compressed to a certain pressure? If so, what is this pressure?
I also thought perhaps it was a conversion to a litre of liquid hydrogen?
Or is it neither of these?
Is there a conversion between standard litres and kilograms for Hydrogen?