Foldable 5V solar panel to power or recharge portable devices

This is a foldable multi-page solar panel based on inexpensive 100mmx69mm epoxy covered solar panels which can be bought on eBay for less than $3 a piece. One of these panels delivers 5.5V @ 150mA under optimal conditions (full sunshine at noon). So combining 5 of them in parallel, will result in a power source that easily delivers 500mA over most sunshine hours during the entire day. That power can be used directly via an USB cable to drive or charge any of your USB powered mobile devices or alternatively to "collect" the sun's energy in a Li-Ion USB power pack used from which you can charge your mobile devices later on.

The challenge in this project was to combine several such solar panels in a foldable compact stack, so that I can take it along easily on all my trips.

The STL files provided here are for a pack of 5 panels, but the SCAD file is parametrized to allow for any (reasonable!) number of panels in the pack. Also, it is of course possible to use solar panels with a different voltage and/or wire them differently in order to get a foldable solar panel for other purposes.

Update 2014-11-08: I just uploaded a new version of this foldable solar panel which uses larger 150x130mm solar cells that deliver 500mA at 5V each._