Hydrogen is really interesting in that, being the lightest known element, has a really good gravimetric energy density or energy to weight ratio, a much higher ratio than kerosene in fact. The issue though is that it has a really bad volumetric energy density or energy to volume ratio, even with liquid hydrogen you need much more of it to equal the same energy as jet fuel, and a huge issue with commercial hydrogen planes is that it’s hard to physically fit all those tanks while still having room for passengers. So in a situation like this, can one of the huge jets like the 747 or A380 be a potential solution? Since hydrogen is lighter than jet fuel but take up a lot of space, a plane running on hydrogen would probably be slightly lighter for the same range, but will need to accommodate fewer passengers, possibly much fewer due to the hydrogen tanks needing to take up fusalage volume as we don’t currently have any practical way to fit them into the wings, for something like the A320 and 737 that can seriously cut into your capacity, probably taking it down from a medium haul medium capacity aircraft to the realm of regional jets at best, still with the same external volume. But wouldn’t a huge plane be able to absorb those volume losses by having more volume in general? Therefore I’d imagine the capacity-range sweet spot for hydrogen planes might actually be larger than normal planes. Even if not the biggest planes like the 747 and A380, maybe we’d mostly be using widebodies in a hypothetical timeline where hydrogen becomes the norm in commercial aviation?
Could this be something that can happen or am I totally wrong here?
In theory, yes, I suppose so, but in reality you’d need to do the math to get an answer to your question. The thing here is “huge” is a relative statement. Does “huge” mean 747 sized? Or does it mean 4x 747 size? Because something that large is likely not practical for reasons aside from hydrogen practicalities.
Assuming it were possible to work through the engineering of such a plane, you’d also need to completely rebuild airports to account for something that big (see the 777X with folding wingtips to avoid the problem of needing wider gates). That said, I’m sure someone has already done this analysis and came to an unfavorable conclusion because if it checked out Boeing and Airbus would be racing to have hydrogen airliners ready to go in the not too distant future.