[cryptoz]

Well, I do have a vision where solar power is actually enough, but that's certainly not possible today. This might work in 3-4 years, depending on what happens in battery tech and solar efficiency. Otherwise, I think you might have to build a network similar to Matternet [1] / Tesla Supercharger; making a ground-based charging infrastructure investment might be necessary to get started, even if that tech isn't necessary in 10 years.

[1] Matternet is awesome. http://matternet.us/

[Lexarius]

Have you considered buying solar-powered drones from Titan Aerospace before Facebook snatches them up? Probably a bit pricey, but they are marketed as atmospheric satellites.

[cushychicken]

Titan Aerospace's offerings are tailored for high altitude use - this gentleman is looking for drones flying under 400 feet. Different application.

[luckyno13]

I know I am way over simplifying this but I always thought integrating something similar to the Roomba's ability to find "home," land, recharge and resume would be a nice solution.

[fixedd]

Better yet, have it find an overhead power line ;)

[fooqux]

Oh sure, the FAA wouldn't mind that at all. ;)

Besides, the various utility companies would surely not be pleased by the theft of energy.