Citizen, Seiko, Casio... have solar watches. I really like to have this kind to complement automatics, because it's the kind of quartz that requires less maintenance and it is easier to charge (compared with kinetic / auto-quartzs). If they are radio controlled, you don't even have to worry about setting the time.
But, how long does it take them to fully charge (from empty), using solar light (not exposed directly to the sun)? And how long to discharge in normal and power save modes?
I have a Citizen Eco-drive with H145 movement and it takes 30 hours to charge, it lasts for 6 months of normal use without being able to charge, and 2 years in power save (it sleeps after 7 days in darkness). You can check more Citizen movements at -> Citizen Watches Co Ltd / Eco-Drive Charging Table
Please post your experiences with solar watches.