Fun to see this problem tackled again, I worked at a startup during the boom around a decade ago. Startup failed less than a year (mixture of funding drying up and a shitty founder). Wonder if the technological landscape has changed enough where this is business viable.
Quite a lot has changed in the past decade. Li-ion Battery energy density has roughly doubled, solar tech has come a long way (both in efficiency, but also production scale/costs for commercial silicon cells), and there’s been a wave of improvements for miniaturized drone/UAS hardware. On top of that, there’s 50 years of existing research into solar flight - we’re lucky that we can learn from that!