I looked up the stats for a Boeing 787 Dreamliner. The fuel capacity is about 126,000 L. Judging from Wikipedia, you&#x27;d need ~5× the amount of space to store pressured hydrogen for the same amount of energy. Wikipedia also says that the cargo capacity of the same 787 is... 172,000 L. I don&#x27;t have hard numbers on the size of passenger space, but guesstimating that as the upper half of a cylindrical tube gets you in the region of 1,800,000 L. So you&#x27;re looking at taking out 10-20% of the revenue space of an aircraft to fit in hydrogen fuel tanks.<p>Now the 787 isn&#x27;t the largest craft out there, but spitballing the 747 gave similar numbers. I also don&#x27;t have numbers on how much less fuel you&#x27;d need for the lighter weight (you&#x27;d reduce the weight of the aircraft by ~⅓ with equivalent amounts of fuel). If you assume it&#x27;s more or less linear, you&#x27;re talking about using ⅔ the fuel, which would be cutting out &quot;only&quot; 5-10% of revenue space or cutting your range by ⅔ and keeping revenue space the same.<p>Given the amount that airlines are trying to squeeze out of the existing revenue space already, it doesn&#x27;t look like a particularly appealing trade-off.