Right, boil-off is a problem for general aviation, so compressed H2 is the hydrogen option there, which is less attractive. Although, Universal Hydrogen[0] has

Right, boil-off is a problem for general aviation, so compressed H2 is the hydrogen option there, which is less attractive. Although, Universal Hydrogen[0] has a wild idea: "... the development of a state-of-the-art uncooled liquid hydrogen storage system that will be able to store liquid hydrogen without venting for over two days. This storage life will be achieved through the use of a specially insulated dual- walled aluminium capsule that allows the pressure inside to build up without exhausting the boil-off." Yikes. [0] https://hydrogen.aero/career-list/?gh_jid=4150445004 https://hydrogen.aero/career-list/?gh_jid=4150445004