Lifting and moving mass can take quite little energy compared to actual air travel energy consumption. Lifting 100 kg straight up by 1000 m at the lower bound o

Lifting and moving mass can take quite little energy compared to actual air travel energy consumption. Lifting 100 kg straight up by 1000 m at the lower bound of physics takes ~1 MJ. But real life air travel comes to 1+ MJ per just horizontal passenger-km.