This is freakin' groovy: Photovoltaic panels + bike share at a train station + Sanyo pedelecs = a bike rental station where the electric bikes are charged through solar energy.
Sanyo announced the grand opening of two electric bike rental stations for "community use" at two train stations in Setagaya, Tokyo Japan. The city will operate these bike share stations. Sanyo built these to demonstrate their "Smart Energy Systems" program combining clean energy generation, rechargeable batteries and technology to make it all come together.
I had this idea of doing such, found three sets of panels, 2 portable, 1 roll-up and the other a foldout cloth-bound version. All available from Alibaba and Chinese manufacturers.
Either way, depending on how patient you are, it is do-able now. If you can output 18V 5A you can use any RC charger with the correctly wired battery pack. 6S batteries can be charged 4 at a time from some of these chargers, albeit slowly.