Indeed. I expect we&#x27;ll synthesize jet fuel or a close equivalent (something that burns and reduces airframe weight) from electric or bio sources long after most other engines have moved to electric. Perhaps we&#x27;ll generate electricity on board, but it will be with a dense, wasting fuel.<p>And we certainly aren&#x27;t going to use solar to power commercial human air transport any time this millenium; it will always be better, for people, to compress energy before a flight and travel faster, than try to make the flight itself self-sustaining and travel slower. The only exception could be recreational flyers.