- Urban Aeronautics moves to hydrogen for its CityHawk eVTOL air taxi. "H2 is becoming one of the most exciting techs in the emerging electric aviation mkt, with exceptional energy density compared to lithium batteries, as well as super-quick refueling as compared to long waits on a battery charger" https://newatlas.com/aircraft/urban-aeronautics-hydrogen-cityhawk-evtol-hypoint/ 8 comments energy